[SOLVED] Cylinder 1 Misfire - P0301 / P0300 Mystery
 

Turned out to be incorrectly installed keepers on one of the exhaust valves (cylinder 1), causing an exhaust leak.

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Hi! Looking for help to track down a misfire on cylinder 1 for a 2007 e70 4.8i. Any help appreciated

P0301 - Cylinder 1 Misfire [0029CD]
P0300 - Random Misfire [0029CC]

Check Engine Light On
Rough Idle Cold & Warm
Some hesitation under load
All new Plugs
All new Coils
Cleaned Vanos sensors
Switched plugs and coils around (cylinder 1 & 2, 1 & 5), even tried old plug/coil in cylinder 1, no change in code
Changed coolant hoses (to fix a rotted fitting and associated leak)

Have replaced Valve Cover gaskets and all related sensor seals (vanos, eccentric shaft, upper timing cover, vacuum pump etc) during valve stem seal replacement
Have replaced worn crankcase vent pipe (was leaking)
Smoke tested (paint can/mineral oil from ebay) and see no leaks from intake or crankcase

I haven't had a compression test done yet, however, there was no misfire or roughness and no CEL (at least not like now) prior to all the work done above (all at the same time) even though it leaked oil/coolant and smoked like crazy.

I did have the engine partition off to make room and so I could replace all four major parts. The lower center piece was a pain.

I checked the voltage to cylinder 1 fuel injector and wiring and listened to it tick, all numbers matched specs and it sounded like it was operating correctly.

I'm wondering if water/moisture from rain during the 2 weeks I had the engine apart might be the cause. In ISTA - the Oxygen Sensor State for Bank 1 doesn't fluctuate at all (no mater the engine state) like bank 2 does. Fuses are good (30 amp under the footwell).

I'm new to INPA/ISTA but here I've attached an image of the value I'm talking about.

Check compression. Looking at oxygen sensor voltages when you have a dead cylinder is probably just going to confuse you.

Feels like there is something causing one bank to hit the rails on AFR- which is causing the misfires. NOT a 'dead cylinder'.

Air leak, broken hose, crack, etc perhaps

Thanks both.

I am going to get a compression test done and have the gaskets for the intake manifold in case there's a leak I can't see with the smoke machine. Don't have the seals for the injectors though, and would like to replace them since I'll be in that area.

Lot of money to spend on something that prolly wont tell you a thing...

Trick is to look for a leak. NOT replace parts willy nilly hoping you guess right.

IMO

Tried looking for a leak multiple times with a smoke machine, no luck. Might look into UV dye and see if maybe my eyes are just not good enough. :D

Haven't done anything since the holidays/freezing cold hit, except finally get something to log the fuel trims.

Dropbox link for anybody that cares to take a look. Bank 1 stuck in open loop it seems.

https://www.dropbox.com/s/x793oob08z...12018.xls?dl=0

Where did you input the smoke from the smoke machine? If you have not already done so, it's good to input the smoke from the oil filler cap; with the intake sealed off. Snap-on (Blue Point) makes a blue stretchy rubber smoke machine adapter that will work with our oil filler hole. Second, Snap-on sells smoke fluid that has a UV dye in it; ($$$$$) so you can use a UV flashlight and those yellow safety goggles to better see a small leak. Third, you need to have somewhat pressurized smoke to work well...not sure that your paint can will do that; does it connect to your shop-air?

I have the smoke paint can hooked up to shop air with a regulator dialed back to 3-4 psi. I've tried the following smoke inputs:

• crankcase vent pipe to intake manifold (left vent pipe itself connected to left and right side, plugged the middle connection)
• directly into the vacuum pump where the booster line connects, since it's bolted directly to bank 1

I have not tried directly in the oil filler cap, wasn't sure about there, so thanks for the suggestion. One place I've thought about but also not sure was the dipstick tube since I've read people having small leaks there.


I removed the intake boot and just put a rubber glove + rubber band over the throttle body (works great!). You get to see the pressure build and it seals well.

Since it's too cold to do anything, been trying to learn more about fuel trims and 02 sensor data. As I (currently) understand it, since sensor 1 & 2 are wideband, then 0.0 mA = stoichiometric. Positive number means going lean, negative means going rich.

Looking at the numbers from a Carly Gen2 adapter + OBD Fusion (pro), looks like Bank 1 is much leaner than Bank 2. I measured 900 pts (changes in reported values) and compared them, along with RMP and saw the following:

Average Bank 1 - .505mA
Average Bank 2 - .163mA

Average difference between the two over that time = 434%

This appears to be more evidence of unmetered air/vacuum leak... ? Sprayed Carb cleaner around Cylinder 1 fuel injector and intake while watching RPMs, didn't notice any changes.

This data is meaningless if you're got misfires or a disabled cylinder pumping raw air into the exhaust. This creates a lean condition the DME can't possibly correct. You've ruled out the coil and plug, I would replace the fuel injector.

Have you tried cleaning the MAF? I was having misfires on my E46. Cleaned the MAF and it's been running great since.

I have cleaned it, twice actually. Unplugged it as well with no changes other than getting a code.

Out of curiosity, was the code for an intake air temp sensor?

(MAF has a temp sensor in it, along with air density...)

I honestly don't recall. It was one of the first things I tried, hoping for an 'easy' fix. As soon as I plugged it back it, the code resolved itself.

However, I just unplugged it and these were the codes presented specific to it:

P0113 - Intake Air Temp Sensor 1 Circuit High
P0100 - Mass or Volume Air Flow Circuit
P113B - "Manufacturer Defined" - Mass air flow (MAF)/volume air flow (VAF), 1 – incorrect signal


In other news, UV dye and light kit delivered yesterday, so will be playing around with those probably later this week or over the weekend to make sure I've covered all the bases for an air leak. At least, for my own peace of mind. Will try looking for leaks as suggested earlier and exhaust as well.

Also, I have had a replacement injector for some time, so that might happen as well. I've discovered it's much easier to have a part on hand and not need it than no part at all. Only reason I haven't replaced it already is I've never done that type of work (coding, index numbers, etc, etc...) and didn't want to go that route till I was certain or had no other options. Plus, most of what I've read and Indy's I've talked to suggest replacing the entire bank.

Dont just concentrate on the big items- a hose leading off somewhere with a cracked elbow or split in the middle can be a hidden culprit

N62 injectors don't need coding, they're plug-n-play.
Hmmmm.....now what possible motive would a shop have to recommend replacing all 4 injectors when only one cylinder has a problem.....:dunno:

I would assume I would need to reset adaptions at least?

Most of what I've been told is it's 'better' to do the extra work since you're already there and you may end up having to replace one or more of the rest anyway, depending on the root cause.

Probably not much gain involved for a shop only doing one vs 4 to 8.

Adaption reset is not required. This is easily DIYable. For the most part fuel injectors are life-of-the-car parts. Replacing 3 or 7 functional injectors at $140 each is money down the drain.

Just changed the fuel injector since it was a little warmer today and that was much easier than I expected. Thanks for the confidence boost!

Result: runs a little smoother but still same codes and same idle/driving issues as before.

More smoke testing and Compression test is next on the list. Is this something that can be done at home with a compressor and leak down kit? I've never done a compression test myself. Looked around online and not sure exactly how to do it still. Does anyone know of a guide specific to the 4.8i?

Also, took some pics of the intake valves for cylinders 1-3 since I had the injectors out.

Congratulations on the repair, too bad it didn't help. Compression check should be next. How many miles?.

149600 miles

I really thought this would point you at the issue....

Can you run a Vanos Function test??

Not exactly sure...

Went through ISTA to see what I could find. This was the closest I came. Let me know if I should be looking for something else/more specific.

A VANOS problem should affect all cylinders in the bank, not just 1.

1. I dont think that is a vanos function test. Just the status. INPA has one, at least for my M62

The vanos function should try to position the vanos at the extremes...if it cant, thsi MAY cause the engine to run very rich or lean in certain RPM bands.

2. I am not convinced this is a singular "only cyl 1" issue. OP reported cyl misfire AND 'random' misfires.

While trying to figure this out noticed a coolant leak and spent quite a bit of time trying to track it down. Thought maybe the valley pan based on others posts, but couldn't quite tell until I used some UV dye - made it shine bright...

Would a bad valley pan gasket cause a misfire on a specific cylinder or just account for the random misfire code (P0300)?

Update: Have the intake off now, break for lunch, then will get back to getting the valley pan gasket off.

However, wanted to see what people thought about the condition of the intake valves...

Does it look like the intake seal has failed and this could be the source of the misfire? There's a good bit of buildup on cylinder 1 of oil (?) and some of the rest have a similar, but less sever buildup. Also, the first nut on Bank 1 was not as snug as the rest.

I could never get smoke to show there or get the idle to change with any type of spray.

In case you're wondering, coolant looks green due to the UV dye as I do use BMW blue.

Clearly the valley pan needed to be done; if not the coolant transfer pipe as well. Probably unrelated to your issues though.

That oil build up is pretty significant. Have you ever done the valve guide seals? You're a bit beyond the normal mileage for that, so it's likely an issue. I'd be surprised if you were not seeing the significant symptoms of that: Idle for a few minutes then hit the gas and see a large cloud of white smoke out the exhaust.

If you decide to do the seals, I have an AGA kit for rental in the "For Sale Section". PM me for info.

Yep, I've done the whole smoke screen deal and got a t-shirt :rofl:

Replaced the valve stem seals last part of 2017 before it got cold. Had the misfire ever since.

The first nut on the Intake (bank 1 side - front corner) was not torqued down properly when I started pulling it apart, so I'm hoping maybe, just maybe whilst laying across the engine a few times to do the valve seals that particular nut loosened up enough to cause a vacuum leak I couldn't see (even with smoke) and caused this whole mess.

I used the AGA set and a lot of patience!

Currently in the middle of cleaning up the intake and ports as carefully as possible... (new BMW valley pan gasket in place)

Well, the plot thickens! So if the misfire started right after you did the valve seal job, that tells us something. Either something you did wrong caused the misfire, or it was just a coincidence. As for me, I'm not a big believer in coincidences.

For starters, I'd look all the way around the valve covers very carefully for any signs of an oil leak. You'll need a mirror for the back ends. I'd also pull all the coilpacks and shine a light into the tubes to see if any oil is in there.

Prior to the valve job - oil in abundance - fixed all leaks (mentioned in first post) - currently leak free. I've checked that so many times I have multiple mirrors, some with lights, and a camera now just to be sure. :rofl: Have felt all the way around (except the very back side against the firewall) and nothing.

I've checked the first intake and exhaust springs/rocker/seals closest to the front with the camera through the oil fill and they look fine. Can't get the camera at a good angle to check the other two for cylinder 1.

As far as oil in the coil pack / spark plug tubes - dry as a bone. Spark plug does have oil build up on center and ground electrode (tip) not on the threads. I've tried the plug that was there to start with + new NGK and Bosch (no change).

I've swapped so many plugs / coils around I can do it sleeping now.

Did you replace intake seals?

Have you turned on the engine after you replaced intake seals?



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Btw, to test your vanos in ISTA, go to service functions-power train-Vanos
You can reset your vanos /and realign the angel there.


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New seals are on the intake, but I haven't got to the point of installation yet, so yes to the first question and no to the second.

Going to see if I can pick up some injector o rings tomorrow and replace those while it's super easy to get to them. Then reinstall everything, fill up with new coolant/bleed the system, then see what happens...

Oil on a spark plug can only come from one of two places; from the valve seal, or a bad ring.

Did you ever do the compression test that was suggested early in this thread? I wouldn't throw any more effort at this engine until you're sure you don't have a bad ring.

Assuming the compression is OK, you might consider a chemical decarbonization. There are devices that hook directly to your fuel rail to spray a chemical solution into your engine. Basically, you shut down the fuel pump, so the engine runs for about a half hour on strait solution, at a set pressure. There are two different types of solutions; one that is designed to decarbonize, the other is an injector cleaner. This is the rig you need:

https://www.amazon.com/OTC-Tools-764...70_&dpSrc=srch

This listing is the basic kit, and comes with a few adapters. They make a "Pro" kit that comes with a whole toolbox full of adapters at a higher price level:

https://www.tooltopia.com/otc-tools-...tid=OTC6550PRO

That last link also has some videos.

I bought one of these kits to clean out the engine on my G35, which DID have bad rings, and was burning a quart of oil every 500 miles. Worked pretty well, car ran a bit better. (Those V6 Nissan engines are really crap, and when the car needed a third engine at 150k miles, I sold it.)

Compression test is on the to-do list this weekend. When I have some extra time, I'll probably be pulling the valve cover off to take a look, unless some miracle happens.

Intake is back on and the coolant leak appears to have been fixed with the new valley pan. This seems to have taken care of a lot of the rough idle and the P0300. Carly and OBD Fusion tell me the same thing, but I need to reinstall ISTA (changed laptops recently).

I'll look into the decarbon links - thanks!

Code
 

Does it have an individual throttle body? If It does, you will need two people. One to punch the gas and another to make sure the rod opens the plate. Just repaired M3 with an all else failed tactic as you are facing. Mine was a P0306 code due to this. Youtube: DIY_NATION_TH

Another update: Finally got around to trying my hand at a compression (wot - two people) test on Bank 1, couldn't get the gauge to hold the psi so thinking the tester has a leak somewhere - will look into that and/or get a different gauge and do a complete retest of bank 1 - but till then...

Cylinder 1 would only go up to 30 psi. Cylinders 2, 3, and 4 120+ (couldn't quite tell since I couldn't get the needle to 'stick'.

Put about 3/4ish table spoon of oil in cylinder 1 and tested again with no change.

On the bright side, new intake seals seemed to have made a difference with the plugs. ?? Cylinder 1 isn't fouled like before and by now I would have already seen a good fouling.

I did pull the valve cover off over the weekend too, just for peace of mind, and visually checked the rocker arms, levers, springs, etc and everything looked good.

I've changed the oil a few times since last October and checked numerous times in-between, never saw any abnormal qualities (foaming, bubbles, etc). Also, coolant doesn't appear to have any oil in it and is holding steady since the valley pan change.

No oil leaks from the cover, no oil in the plug tubes either.

Lastly, I think the filthy condition of the engine due to all the [ignored] oil leaks/valve stem issues left over by the previous owner is why the plug threads look the way they do. Every time I do any work I try to clean them but seems nearly impossible to get all the gunk out of those groves (cylinder head). :rofl:

Well that compression test is NOT a favorable result. Usually, when adding oil does not bring the compression up, that means the leak is through a valve. This is better confirmed with a leak down test. When you add shop air to the cylinder through an adapter into the suspect cylinder, you can see where the air comes out; oil fill cap, tailpipe, or intake. I could see a scenario where a valve guide seal was bad for so long that the carbon build up is now preventing a valve from completely closing. Was this car exhibiting the classic signs of bad valve guide seals? (Punch the gas after idling a few minutes and get a big cloud of smoke out the exhaust; but otherwise running more or less normally.)

Assuming it's an valve leak, you might want to get a boroscope into that spark plug hole and see if you can determine what's wrong. If there's heavy carbon build up around the valves, getting that removed might solve this problem. I had previously suggested a way to do that.

Second/new gauge + leak down test is the next 'to-do'. I'll post those results (maybe early next week) once done.

Yep, I didn't wait very long to do the valve seals once the smoke started (maybe a couple of weeks, after heavy research). No lights up to that point, and a couple of codes that I fixed. One for coolant, which was a rotted fitting for the upper radiator hose and one caused by a bad seal or crack in the crankcase vent hose (replaced same day). No other codes or Lights.

The cheap boroscope I have stopped working, so need to pick another one up. Went to use it while I had the valve cover off and no picture. :( I know for sure the top of the piston is covered.

I've been looking at the kit you suggested and am 95% sure I'm going that route before anything else. I've keep hoping it's a sludge/carbon issue that just needs to get cleaned up.

As far as the boroscope, I've been seeing a lot of ads for one that hooks to a smartphone. Looks very promising and quite a good deal. But if you can get your hands on a really good one, (like the Snap-on unit); that's better. I know some of the more recent high end models have an optional head for the probe that can look up and in different directions. You're not really interested in a view of the piston; you want a close look at how the valve is seated.

As far as the decarbonizer set up, where are you located? Close enough to borrow mine?

Just north of Atlanta, so not too far away. :D

Mine came with a mirror attachment, but it was too unstable to risk losing it in the cylinder.

Another Update:

Got the new camera Friday and tinkering with it this afternoon. Much better image quality than the other one I had. Only issue is it's focus distance made it hard to get a good clear image of the valves.

Video of the valves closed - trying to see if they were seated properly - if you're curious: https://youtu.be/2GxCPxO9ZjU

(Didn't see any signs of a bent or burnt valve, just covered in gunk- though I'm certainly no expert)

I've been looking at the kit, but the decarbonization fluid was discontinued (OTC 7904A1). I called OTC and they didn't have any replacement. I've googled around and haven't found anything I'm confident using + buying the kit. Any thoughts?

I found someone on eBay selling 1 can for $80 + $20 shipping :bustingup

I've used MotorVac CarbonClean MV-6

Here's a link: ($11.38)

https://www.ntxtools.com/network-too...=NTX%20Desktop

Thanks! Will be purchasing the kit Friday and see what happens.

In the mean time, I finally got a new OTC compression set, which actually worked. The one I had from Sears now seems much lower in quality.

*Cylinder 1 measured just a hair over 70 dry, I think. 90 Wet.

Attached a pic of Cylinder 2 intake valve for comparison to the other pics previously posted of Cylinder 1. So clean in comparison.

*my son thinks he hit the schrader valve on the gauge before giving me the number, but forgot to tell me until after I did the wet test. So... will do it again before the OTC cleaner/decarb run.

Ordered the OTC 7448A, OTC Adapter 549578 (per OTC should work with 07, 4.8i), OTC 7000A cleaner - 1 can, CarbonClean MV-6 Max Strength - 2 cans. Spent $100 less for all the above compared to just the 7649A kit. The adapter #'s OTC gave me for the X were not listed with that kit and I'm assuming there's no need for the decarbon adapter since the CarbonClean is designed to work through the fuel rail.

If everything comes in before next weekend, I'll do it that Sunday, but the shipping dates for some items range past that time so may have to wait longer.

The plan at this piont:

1. Pick up a combustion leak detector to make sure nothing is found (doesn't appear a single drop of coolant has been lost since the valley pan was changed, but...)
2. Leak down test on Cylinder 1
3. Test compression on all 8 Cylinders
4. Take 'Before' picks of all 8 with boroscope, try to look at valves too
5. Run the 7000A Fuel injector cleaner first
6. Test compression on all 8 Cylinders
7. Take 'After picks' of all 8
8. Run the CarboClean Decarb
9. Repeat compression test/s / take 'After' pics

I know that the fuel injector cleaner probably wont do anything for compression or change the state of the combustion chamber, at least for cylinder 1 since it has a brand new injector, but would be good for others to see separate 'proof' images anyway for both banks.

My assumption is running the fuel injector cleaner first will help maximize the effectiveness of the carbon cleaner solution. ?

Of course, on additional step; pray that one or more of the steps above solves the misfire.

The way this cleaner works is that you shut off the fuel pump, and run the car on the pure solvent. The kit comes with a book that will tell you the pressure to set the device valve at, so you're matching the normal fuel pressure. Or you can put a fuel pressure gauge on before disconnecting the fuel pump and measure the pressure.

The two tricky things are getting the proper fittings to hook up to the fuel rail, and disabling the fuel pump while still allowing the car to run. Pulling a fuse doesn't always do it; some cars you have to physically unplug the fuel pump. I don't know the procedure on the X5. BTW, on the last car I did, (an infinity G35,) the car ran about 1/2hour on one can of solvent. I would guess the X5 is a little more thirsty, so figure 20min or so.

Given that you are burning this solvent instead of fuel, it can definitely have a positive effect the combustion chambers. How much is anyone's guess. Since both the fuel injection cleaner and the decarbonizer are going exactly the same place, I'm also not sure how different their impact will be. I know I have seen distinct drivability improvements from the fuel injection cleaning. But there's a reason walnut blasting is done; the solvent might not be enough. But walnut blasting is far more invasive. It's absolutely worth a try, and the results of your "scientific" methodology will be very interesting.

Finally received the cleaner, so have just done a compression test on cylinders 1-6. 7 and 8 I really don't want to fool with since the fuel and power lines are in the way and just removing the bracket that holds the ignition coils down was frustrating enough to stop. :D

1. 55
2. 195
3. 200
4. 205
5. 211
6. 194

(11 yr old son provided a 'grid' to keep the plugs/coils organized :D )


The adapter for the canister to the fuel line doesn't seem to be correct, so will be calling OTC tomorrow to make sure I have the right one.

Also, I switched plugs 1 and 2 the last time I attempted a compression test and it seems cylinder 2 'cleaned up' the plug that was in cylinder 1, while cylinder 1 'fouled up' the plug that was previously in cylinder 2 (worse than before). :dunno:

Also, one of the first things I did when I picked up this X5 was change out the struts for the trunk and assumed the hood struts needed to be replaced as well. As soon as I hung the empty canister, the hood came down. Thank fully I was prepared. :(

Update: Had to talk to OTC again to get the correct adapter, which arrived today, so did one run of injector cleaner and one run of carbon clean.

On the injector cleaner, it ran like normal, no noticeable difference once I dialed in the right pressure (33psi). The carbon clean ran like I've seen people using stuff like seafoam, where it bogged down, nearly died several times, etc. No smoking out of the exhaust though. I went to run the second can of carbon cleaner but couldn't get it started, so hooked the regular fuel line back up and gave it a quick spirited drive. All the numbers I normally look at didn't seem to be different (INPA, OBD Fusion).

Misfire still there. :(

Also, did a compression test after and will take some pics tomorrow after it's cooled down, and then run the second can of carbon clean through.

Compression Numbers:

Before cleaner / After cleaner

1. 55 / 22 <-- seems strange it went down ??
2. 195 /208
3. 200 /215
4. 205 /210
5. 211 /207
6. 194 /200

(didn't bother with 7 or 8 due to difficulty/laziness with access)


I reset all error codes before and then after all of this, no change, yet.

By far the. most. difficult. part of this process was getting that fuel line disconnected. Next after that would be tying into the fuel line with the adapter, without removing anything from the engine. :D

Rest was easy. Hook up canister, add cleaner/solution, add shop air, get pressure correct, disconnect fuel pump (one relay in the rear cargo area), start vehicle, wait.

Note for anybody who might want to try this in the future: the adapter I ended up with, which worked like a charm, was OTC's 518476, 5/16 Ford Inline Adapter.

Lastly, it did feel slightly smoother and even more so at higher RPMs (3000+).

Am I missing something or is your Cylinder #1 damaged?????????

Sure sounds like it. Bad rings, leaking/burned valve(s) or valvetronic problem.
This is a Valvetronic engine correct?
It would be nice if we could check compression with valves at max lift.
I recall reading about intermediate levers wearing and causing problems with valve lift particularly at idle when lift is the smallest. As I understood the problem, worn levers reduced valve lift causing roughness & misfires at idle due to incomplete cylinder filling. This could cause a false low compression reading. The fix was to raise the min valve lift using ISTA(?) as I recall. This higher valve lift gives the throttle plate a larger role in controlling the idle speed.

Did a leak down test on while everything was open and had 100% leak on Cylinder 1 at TDC, but couldn't figure it out where it was going. So... hooked up the smoke machine with an air hose without the schrader valve and smoke (all of it?) almost immediately came out of Cylinder 4 through the spark plug tube. All of Bank 1 plugs are out.

Would this indicate bad rings? Or an exhaust leak and the smoke was just finding the first available path?

Sorry for all the posts, maybe somebody will find all of this (thread) interesting.

Update - I plugged Cylinder 4 (threaded a hose on it) and all the smoke came out of the tailpipe. While that was happening I poked my camera through the oil filler cap to watch for any wisps of smoke inside the crankcase and never saw any.

Would this confirm exhaust leak of some kind? I'm hoping there's nothing bent or burnt. Going to run the second can of carbon clean through a little later today to see if I can't get things a little cleaner.

It's difficult to get good pictures of the exhaust valves, but I did open them up and took some pictures. I also watched the intake/exhaust as I hand cranked to see if anything looked out of the ordinary, but to my untrained eyes, nothing appeared to be wrong.

I have a few ideas on how to get some better, in focus, pics but we'll see.

Can't overlook this coincidence.
I believe all of the cam/valvetronic hardware has to be removed to change the valve seals. Can it be reinstalled incorrectly so cyl 1 valve(s) don't close completely? Can a stuck/failed lifter prevent closure?

Agree.

Or a valve retainer clip slipped off or wasn't properly seated....

Something in the back of my mind is telling me I read something like this before...here or BF...

I took another look at the one exhaust (and intake) valve that I can see through the oil filler cap with my camera - the ones closest to the front of bank 1. Hard to tell anything looking at it from a strange angle though.

Would it be worth the effort to pull the valve cover off and 're-do' the two exhaust valve seals to make sure everything is seated properly? I don't mind doing that again, except for the fact I would need something to compress the valve springs since I rented the AGA tools last year.

Smoke test suggests there is an exhaust valve leak. Certainly worth it to pull the valve cover and inspect, though I can't envision an improperly installed valve seal preventing a valve from closing completely. You can check that valve keepers are installed properly and that valve train gear looks identical to the other exhaust valves. Might put a straight edge across both cyl 1 exhaust valve spring retainers, they should be the same height. If they're not, then one is open/damaged. You can remove the valvetronic gear, forcing valves to close and check compression again. If it's still low you get to pull the head. Did you have any trouble re-timing the engine after valve stem seal replacement? Any piston-valve contact while turning engine over?

Thanks! That'll be my next course of action. Cylinder 1 was the first set of valves I changes the seals on, so it's certainly possible my lack of experience and quality of work is the issue.
This part I'm not quite clear on. Are you saying unclip the electric connection for the actuator (part # 11377548389) or unbolt it? I have uncliped it in the past to see if it affected the misfire, but have not done a compression test with it disconnected.
I did the seals in the vehicle without removing the cams, so did not touch the timing.

As for piston-valve contact, I don't recall ever hearing anything other than air when hand cranking, any time I've ever done that and I can't see any obvious damage to the piston or valve. Though from what I have read I suppose the only way to be sure is a close visual inspection with the piston clean and/or measuring clearances. ?

Edit: Here are the results of the OTC injection cleaner (1 can) and CarbonClean MV6 (2 cans). Results for the top of the pistons are positive, though not as impressive as I would have guessed. The valve stems look roughly the same, however, getting a good image is very difficult at this time. I've attached comparison pics for Cylinders 1 and 2 and pointed out some differences.

Note: For Cylinder 1, I had previously soaked it overnight 3 times using Acdelco X66P Fuel Injector Upper Engine Cleaner, which is why it looks so much cleaner and you can actually see parts of that piston without contamination, thinking the Piston Rings might have been the problem (obviously not now). That product did much more to clean the top of the piston, but obviously can't do much for the valves as you just pour and soak, then remove. Although, I have had fleeting thoughts of getting the exhaust valves open and then filling the cylinder up as much as possible without getting the cleaner in the exhaust port to see if I could get at least some of the valve/s soaking.

There are some videos for other BMW owners using it for Ring related misfires with good results. Cylinder 1 looked just like the other 7 until I soaked it with X66P, in case anybody mistakes it's condition with a head gasket problem.

Not the electrical part, but remove all of the mechanical valvetronic pieces, springs, levers, etc., between the camshaft and valve stem.

OK, good. I thought camshaft removal was required for valve stem seal replacement. If you didn't touch the timing chain, then there's no way valves & pistons would make contact.

Well, you appear to be on to something. Pulled the valve cover off again and took a better look and seems the keepers aren't seated correctly for one of the exhaust valves.

A little bit of relief at the moment, hoping this is indeed the whole issue. Just need to figure out the most expedient DIY to fix it. I guess I'm a sucker for learning the hard way. :D The up side is this problem has increased the number of tools in my garage, experience, and intimacy with what's under the hood of this X5. :D

Does anybody know of a way to compress the spring without removing the cam or using the AGA tools? Some variation of a universal spring compressor? I have an OTC 4573 Universal Overhead Valve Spring Compressor, but it's too bulky to work.

Assuming this is the actual problem, once I get this rectified and (hopefully) no longer have a misfire I'll update the thread title/first post for others.

Well that sure looks like the cause of the compression problem. Valve stem in right photo doesn't even stick thru the retainer. Where did the keepers go? I wonder what prevents valve from dropping into cylinder......friction w/ valve stem seal perhaps, hopefully it isn't bent.

It's hard to tell from the picture, but the top of the valve stem is actually where it's supposed to be.

I think one (maybe both) keepers is still gripping the stem, but somehow under the retaining plate. I took a pick and made sure the keeper is still there. Sadly, the other keeper must be on the 'bottom' side hidden by the rocker so I can't tell if it's where it should be, if that makes sense.

Hope that is it, and no damage is found....

Have AGA tools on the way, supposed to arrive tomorrow at some point, so might be fixed before the weekend assuming there's nothing else undiscovered to tackle and I don't have to replace the spring plate or something - can't seem to find those for sale anywhere (discontinued/unavailable). Thankfully, I still have extra unused keepers I bought laying around somewhere.

I broke the back tab of the eccentric sensor, so will be removing it and inspecting to make sure it's still structurally sound. It popped off quite easily when I disconnected it, so may have been snapped but dangling this whole time. Had a bit of a scare as while searching for that small bit of plastic, I found it laying just inside one of the rear oil drain ports. :wow: Carefully extracting it was not fun, to say the least.


Also, I lost a valve cover grommet somewhere in the removal process, which means tonight is going to be full on search party. It must have been pulled off as I maneuvered the cover out. I imagine lots of time under the engine tonight. :D

I really, really, really hope I can just remove it all and re-install and be good to go.

If you have ISTA, you can test the sensor using one of the service functions to verify whether it works properly.
So you don’t have to remove it.

Keep posting.

DME relies on the ES sensor to command the VVT motor to change the eccentric shaft angle in different RPM ranges, which subsequently changes the valves’ lifts.

If that sensor is faulty, the VVT will be blindly turning the eccentric shaft gear. Which in turn results in rough running.



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I recently re-installed ISTA but get an error every time it loads. I've been trying to fix that off and on, but haven't yet. It's on the to-do list.

UPDATE - Problem SOLVED!

It was the keepers on the first exhaust valve for cylinder 1 sitting incorrectly. Somehow I missed it the when I did the original work, even though I quadruple checked everything and thought I was being meticulous about it. Also missed it the first time I removed the valve cover after the misfire appeared. :dunno:

Either way, I was concerned, to say the least, about getting the spring plate off without damaging anything as I couldn't compress it directly. So... ended up carefully getting the AGA short foot between the spring and spring plate to release the tension on the plate. That took about 1.5 hours to work out ... After that, it was a matter of gently rocking the plate until one of the keepers came lose. I had a bit of a scare though, as the second one fell into a little oil and hid from me for a while. Thought maybe it was AWOL and all those thoughts of potential damage... Very glad I have a number of magnets I can poke around with (found it that way)

Valve stem seemed straight and held near 100% with the leak down after I put it all back together with new keepers. Put it all back together and no rough idle, no misfire, no odd sounds and no codes! :bmw:

Will keep an eye on it and periodically check for oil leaks, but seems it's resolved now.

Final thing was to put on the V8 cover I bought a while back, but has been siting so lonely and sad on a shelf in the garage.

A BIG thank you to everybody that has posted!

Been following this thread for a while. Glad you got it solved. Congrats! You got lucky the valve didn’t drop and bend (or a lot worse). This is a good reminder for those of us who are plannng to DIY valve stem seals to be extra uber careful and tedious.

Congrats!

It sounds very complicated to work on the V8s!
Glad it is fixed now!
Did you tally up the costs? Mostly new tools to the garage I guess!







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Thanks! I hope this thread can help prevent the oversight I made, at least once. :D

I'm really glad that didn't happen. Also glad there was not some other issue (worn piston rings, etc).


Are you insane?! Just kidding, I really don't want to total it all up, but I do have all the numbers. You're right, there's a number of new tools I bought using this situation as an excus, erm, reason to get.

Like most things, this wasn't that complicated after getting into it, just a significant amount of learning for a garage 'mechanic'. This forum was a great source of help.

As far as costs in general, I bought this X5 well under it's value, but probably am just about even now. That includes lots more than the valve stem job though. Other than engine parts, everything I've bought will be used on other current and future vehicles, so no loss there.

The original work I did cost: $883.39 USD.

This included:

Torx sockets/drivers
Hex Sockets
Couple new magnet sticks
Valve Cover Gaskets
Upper Timing Gaskets
Vanos O-rings x8
Eccentric Shaft Sensor Gasket x2
Vacuum Pump O-ring x2
Valve Stem Seals x32
Leak down tester
New Spark plugs
Two Radiator hoses (upper and y hose that connects to it)
Spark Plug tubes
Few extra plastic rivets
New set of keepers (still have four new ones left)
New Front rotors/brakes/sensor

On top of that, I had to pay an additional $280 for an eccentric sensor that broke on bank 2. Free labor help isn't always free. Friend that was helping was a little upset at his wife, and well, I shouldn't have let him near anything for a while. Hindsight is 20/20. :D

Plus, other miscellaneous items/seals (e.g. shop towels, cleaner, etc)

I shopped around quite a bit to find things on sale to keep costs down.

I know I've spent almost as much or maybe more on restoring cosmetic/aesthetics than that though. :D

I replaced the gear shift cover, bought new floor mats (BMW floor mats are $$$), roundels, fixed most of the interior trim, purchased high quality leather refinishing products (cleaner, conditioner, stain - they look nearly brand new), vent tabs, refinished the melted parts of the grab handles, replaced the cargo hold trunk handle, purchased new covers (e.g. V8 engine cover), and new splash guard.

I still have a laundry list of things to do, but it's all been worth it and all been fun, except leaning over the hood and dropping things under the engine into what we loving call the "BMW abyss". That's probably where I've spent too much time! :D Having towels stuffed everywhere to prevent those accidents works great, but when it doesn't...

Plus, I got my kids involved, which was great.

About a month ago, I replaced the timing belt in a Camry and that was boring, tedious, 'easy', and not nearly as rewarding.

:yourock: Thank you!

Nope, the people on this forum that gave advice do though!


Also, just to tidy things up. I've put a couple hundred miles on it after a fresh oil change, passed emissions, and did a compression test on Cylinder 1 just now.



Compression Numbers:

Before cleaner / After cleaner / After 'corrective' Valve stem surgery Cyl 1

1. 55 / 22 / 192
2. 195 /208 / didn't test
3. 200 /215 / didn't test
4. 205 /210 / didn't test
5. 211 /207 / didn't test
6. 194 /200 / didn't test

I've been going easy on it for a while, except for the last few miles home today and it seems like everything is normal, for an 11 year old V8. No misfires, no MIL/CEL, no stuttering, no hesitation, no rough idle, no fouling of Cylinder 1 spark plug.


Only issue that's popped up since all this work was a code for Fine Evap leak (P0442 I think). I bought a new gas cap and that appears to have fixed the issue. Hopefully. :D The old one was original and the seal was really worn out.



I also finally had time to clean off a bunch of grime from the PO's lack of care/old oil leaks (that I fixed) and still need to do some more, but looking much nicer under the hood now.




Now on to all those 'other' codes that need fixing... (windshield washer leak, RLS sensor codes, transfer case oil - 0054C6, TPMS - hoping just a dead battery in one of the sensors)

Really good to hear!

;)

Thank you for the Help!!!

I am encountering the same issue. Misfire #2 and #8. I thought I had the seats on straight. But like you said, there is a steep learing curve.

Thanks

I am helping a friend of my wife's with her 2007/08 X5 3.0si that has a Check Engine light with code P0301 by AutoZone staff. I believe the engine is a 6-cylinder and the code is for cylinder #1 misfire.

I guess a fix starts with checking cylinder #1's spark plug, fuel injection and ignition coil. Please advise on how to identify cylinder #1.

Thank you.

Google. Images. you will get pictures, drwings, firing order, etc. We could tell you but this way you will learn how to fish!

Also, this thread was a great mystery and outcome- but it is a one in 100,000 result. Prolly start your own IMO

Before posting my request in this thread related to P0301, I did google on the Internet and on this Forum. Two pieces of info appeared to have cylinder placement info: one has 1-2-3 and 4-5-6 replaced in 2 banks parallel to the engine compartment firewall/front bumper, vs my vehicle which has the 2 banks in straight V replacement. The other piece of info has cylinders in V placement but with 8 cylinders.

As I was not getting precise description on the Internet, hence my request for expert advice on this Forum.

As to your suggestion of starting my own IMO, honestly I have not done much work with the model and certainly am not skilled enough to qualify for a meaningful piece yet. I did do a follow-up on water pump and thermostat replacement previously with photos and short description of my get-dirty experience.

Well, excellent thread, so thank you for taking time to share your experiences. I am afraid that I might be in a similar situation.
I have been doing “projects” on 2009 4.8 X5 for the last couple of weeks (stem valve seals, coolant pipe, cleaned injectors, oil thermostat gasket, obviously all new seals:valve covers, timing chain covers, spark plugs, etc.). Assembled everything yesterday, but got misfires :yikes:- uneven idling and impaired acceleration. I wiggled the coils, but no change was observed. My plan is to connect to ISTA to see specific codes and what cylinders misfire and then try to swap spark plugs, coils, and listen to injector “clicking” for a troubled cylinder (s). If unsuccessful, I might need to do the compression cylinder test like you had done and then probably take the valve cover off and inspect the keepers and stem valve assembly.


UPDATE: solved the puzzle yesterday. It was actually two issues causing the misfires.
1) driver’s side Vanos soleniods connections were mismatched. Lesson - mark them when disassemble. This particularly important given two sides are connected differently which is counterintuitive. Passenger’s side has short tail going to the top Vanos and on driver’s side the short tail connects to the bottom Vanos :banghead:
2) once solenoids were connected properly, the misfires had improved, but were still there. Checked the codes with ISTA: misfires multiple cylinders and misfire cylinder #1 :sw:
3) pulled out the coil from the cylinder #1 and noticed a drop of oil inside the connector. Cyl 1 spark plug was the first one put back in and it probably got a little bit of oil from contaminated spark plug socket:banghead: the old spark plug tubes were full of oil and the rubber insert of the spark plug socket got soaked in oil as a result. Cleaned everything real good and put back in. Engine started - engine light immediately off and no misfires, took the beast for a test drive around the block - acceleration strong, engine sound as before :woohoo:
Lesson - a little bit of oil in the coil can cause misfires, so clean, degrease tools really well.
4) another lesson learned - when assembling the engine back together don’t try put everything for initial start ( brackets for coils, all plastic engine pieces, reinforcement bar, basically leave out anything that is not critical). Otherwise, if there are misfires, you will need to disassemble again to be able to reach coils, sensors, Vanos, etc.

After the repair, the engine seems pulling stronger. I think the difference is for cleaned injectors that were tripled cleaned with brake cleaner, seaform, and carb cleaner plus new micro filters. :guinness::bmw::2thumbs:

Which plugs did you install? Maybe the wrong ones? Have you checked for vacuum leaks? I did that work and more myself.


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Installed Iridium IK20TT 4702 Denso Spark Plugs from eBay.
I was able to solve the misfires after a day of googling, YouTubing...see the original post above.
No, didn’t check the vacuum leaks, there was no unusual whistling sounds and I am actually not sure how to do that.
Is there a good tread/video on checking N62 vacuum leaks? I’d like to do that. I am suspecting that the intake manifold gasket to the block is getting old and it is probably my next project. I was seeing some wetness in that area but not sure what that was: coolant, oil, or just condensation of some sort.
Want to keep this X5 until the “wheels fall off”. The thing that makes it possible is the strong network of owners and abundant amount of information online. Love this about BMW. :thumbup:

Nice Job!! Sounds like your #1 coil wasn't quite seated.

Thanks. I had pulled and reseated every coil initially to ensure that there was an audible click and there was no impact on the misfires...I think oil contamination of the coil 1 was the final culprit and of course the wrongly connected vanos solenoids.