N62 misfire
 

I had some years ago random misfire in various cylinders.
Then I have unplugged right side cam sensor plug and all the issues were gone. Is it a faulty valvetronic or could it be something else?
X5 e53 04 4.4 N62

I'm not aware the car will run without the cam sensor unplugged. Do you mean the valvetronic connector?

The shade tree diagnostic for valvetronic intermediate levers or valve height setting is to unplug the valvetronic if the idle is horrible; unplug the valvetronic and it will idle fine.

The bad idle usually it the minimum valve setting or bad intermediate levers. Look to see if your VIN is included in the intermediate lever recall on the N62

The sensor is located in the back side of the engine and only on one side (passenger side) is disconnected, other one is connected. The current only DTC I have, with the cam sensor unplugged is: Camshaft Position Sensor "A" Circuit High (Bank 1 or single sensor)

The DTC is also referring exactly to the camshaft sensor.

Passenger = right or passenger left? Bank ones is right. At least a third of Co are right hand drive avoid the vague term of passenger/driver. I think that is a USA concoction from too many people could not remember left vs right.

Anyhow; you made a few statements but not really any questions. What are you trying to solve?

You need to have working CPS for your engine to run properly. Do you have software or scan tool that will read requested and actual cam angles? If so plug in the sensor and read the values.

Also, swapping Banks or intake & exhaust is an invaluable diagnostic tool. More than likely you have a bad cps that needed replacing not unplugging


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The question was in the first post: Is it a faulty valvetronic or could it be something else?

I have one tool with the Autocom/Delphi software, but it seems that I am not able to read the cam angle. Or maybe I just do not know how to use the software properly.

What is doing the valvetronic, when the CPS is unplugged? Is it increasing the valvetronic valve lift? I thought that when the CPS is unplugged, then the system will increase the valve lift and this is why it runs fine when the CPS is unplugged?

With the cps unplugged the computer has no idea when to inject fuel, how much to lift the valve how long to hold them open. The engine must have a limp home mode that's engaged so the engine will run, it probably disabled the valvetronic completely I can't imagine how much power is lost.

You need to have the car running with all CPS and root out the actual problem.

As I said first post, swap CPS bank and see if the problem follows

What are the symptoms? Backfire? Very rough idle? Does it clear up when engine is warm?

Also: when did the problem start? Did it happen suddenly or did it start mild and get worse?


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It used to start some years ago only with cold weathers, when engine was cold it had lots of misfire and engine light and so on. When warmed up then it started to run fine.

After some time it got worse, so it had misfire error also when engine and weather was warm. So basically it did start mild and got worse.

Regarding the power loss I can't comment, did not notice by butt feeling no loss.

I think you might need to take the X in to a good indy mechanic and have them look at it. If you have had problems for years I'm not sure you have the ability to tackle it.

No offense intended, just an observation. I was having the same issues Andrew is following the posts for symptoms or clues as to what is going on. Swapping cam sensors (if same part number) is a great way to diagnose a bad cam sensor as a start. But you are going to need to read out cam angles, voltages, and other real time data to diagnose this particular issue. How many miles on the X5 currently? How many when problems started?

Shoot, I seem to recall problems with the electrical box on the right side of the engine bay causing issues for some (IVC? IVS? I forget the acronym). That sound familiar Andrew?

When I estimate, then the problems have started with the mileage around 270000 and now it is somewhere around 290000.

To be honest I have not dealed with the issue for a long time at all since when I disconnected the CPS then the X drives without an issues. But I would like to start working with the issue now more deeply.

@ CW, good call.

IVM aka "Integrated Supply Module"

It cracks me up how they keep the German abbreviation but translate the part name to English. My favorite is Drive Away Protection is of course EWS.

https://uploads.tapatalk-cdn.com/202...d91830eac1.jpg


BMW 12-52-7-510-638 Integrated Supply Module https://www.amazon.com/dp/B00NQFCUEA..._RtQvEb1WMQJVW

That part can cause symptoms like described it regulates the voltage for most of the brain boxes of the car.

Sorry, but I do not catch the point with the IVM, EWS or how is it called.

Do you mean, that this can cause the issues, with what I am dealing with or? :)

N62 misfire
 

Duplicate post

IVM controls the voltage that controls almost everything so when that fails it makes it look like other parts fail. It can just be the IVM. EWS not related I was just making example of the weird noon matching acronyms


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Is there some method to test the IVM without replacing it?

Not without really digging into it. Here in the US it's ~$95. I'd just replace it. Probably going to do mine preventatively soon.

I have found this thread by googling: IVM or why my engine runs sluggish??? N62 applies to ALL cars with it. E53/e65/e60/e63/e64/e66 | BMW LOGIC7

Seems that the common issue is bad solder contact in IVM, luckily my all day job is related to PCBA manufacturing so I will check it out myself first before replacing it :)

I’m having the same issues except I have 3 constant code of cam shaft outlet cam shaft inlet and vanos bank 2 . I swapped vanos from both sides. Pulled the valve cover and replaced the cam shaft sensor ? Any ideas

I've fixed plenty of things including both of my keys with reflow.



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The point of swapping is to determine if the fault changes sides. You said swapped vanos which requires removing the valve cover and re-timing the engine. I think you means vanos solinoid.

If you swapped parts and error moved that is the culprit. If you swapped parts and the error didn't move you have work to do.

There should be FOUR CPS on N62. You said you have errors on both CPS left side. I would replace both with OEM grade don't use discount CPS.

Vanos error could be ripple effect but if you swap vanos solenoid banks you can determine that.

I would swap all four solenoids and replace the CPS in the bank with the error.

I am getting the same codes after the switch and I also check the internal chain on that side no play .i also replace the cam shaft sensor

You can't really tell if chain is tight with poking and prodding. It only really is tightened from oil pressure. The chain tensioners should be replaced every 60-70,000 miles.

A couple people have said the reluctor got loose on there N62 throwing the timing off. Did you take pictures with the valve cover off to try to compare and and chance you locked the crank at TDC to confirm timing set correctly?

Today morning I have plugged the CPS sensor connector back to its place.
Warmed up without any misfire sympthoms, after driving to work for around 5km the CEL blinked a couple of times, but the CEL did not stayed illuminated. Most probably it will after some more driving.

The car is a early 2004 model, so most probably the issues are caused by the intermediate lever arms (or how are they called) ?

When comparing the power between yesterda (CPS unplugged) and today (CPS connected) by butt feeling, no difference....

Does it make sense to mess around with the valvetronic valve lift settings? Increase the valve lift.

NO...

That will start a whole other set of issues


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Now had horrible misfire and it was undriveable, disconnected the CPS again and runs fine.

Perhaps the CPS is bad and when you unplug it it goes to a default set of values to run the engine.

So I went and pulled the ivm no issues .have vanos ordered but also thinking I need to change the timing .how would I tell if it’s bad ?

That's what I was thinking but also the valvetronic I think just stops working completely when CPS unplugged.


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When the CPS would be bad, should the misfire also not be only on that bank, on which the CPS is bad?
Unfortunately I am also quite convinced that it runs better when CPS is unplugged, since the valvetronic is disabled when the CPS is unplugged :/

I have read around, that some vanos solenoids can also cause this issue? Any comments regarding that?

N62 misfire
 

In your case if the valvetronic is misfiring, than disabling it may give a smoother running engine but it's not operatinf well.

Think of it this way:

If without the CPS plugged in you might be at 75% power which might feel ok, but plug in and it's 50%. Both are terrible. You will not solve the problem with CPS unplugged that is a guarantee

If you have errors on one bank only you can swap any parts to test: CPS, vanos solenoid, etc. Swap any and all external parts to exclude them before siding inside

What other issues it will start? Is the option to change the valve lift not there to make it possible to diagnose if the issue is in valvetronic etc? Readed this from one local forum.

Check the lower vanos solenoid on my n62 the timining chain has gone bad and eaten upp the solenoid. Dont ask how this is possible... p0021 error code and missfire on random cyl.

I've been informed people for years to replace your chain tensioner regularly else this sort of thing will happen.

Would that have happened from pulling the vanos out without "parking" (forgot the actual term) the vanos previously? What I mean is advanced the chance of damage.

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Chains tensioners and guides was done about 30000 km ago according to the papers and reciept that followed with the car, what happen with the tensioner that can cause this sort of damage? I work as a mechanic and I can´t se how its possible that the tensioner can stretch the chain without breaking. it must be a couple och centimeters longer now than before.

Now I have to replace both timing chains guides one solenoid etc...

The only reason I can see is that the chain has strechted or some of the links broke. Perhaps as previous post wrote that the tensioner gone bad but I can´t se how.

N62 misfire
 

Chains don't really stretch. A 180,000 mile chain from an M62 I measured about 8-10mm longer than new (less than 1/2%).

Tensioner loses tension allows the chain to slap around. It's how the M62 chain takes out the guides. The N62 has one piece guides that are more robust and much shorter chains using two vs one.

I haven't looked into the exact geometry to explain the example above but usually the chain won't start "chain sawing" through the engine until the tensioner stops working and enough slap builds in the chain to tear out the guide and then the free slip of the chain becomes inches vs mm.

It was quite a pressure from the chain on the vanos solenoid, nearly impossible to get it out. Can´t imagine that it´s the tensioners fault but it can be bad chains.

When it´s time to do som work on it I will find the fault and let you all know.

N62 misfire
 

Tensioner will stop providing tension. At this point the chain gets loose and "whips" think of a bull whip but made out of steel and pushed by unlimited force of the momentum of a V8 engine!

Pretty bad to fail so quick: was the tensioner OEM? I've seen non OEM I sent right back because the design didn't even LOOK similar no way it would function the same. After that one example and helping rebuild several engines that had internal destruction I would never use a non OEM tensioner.

I'm not familiar with the geometry of the N62 but did the chain "derail" and jump off track of the guides to get onto the solenoid?

There is no chance the chain from N62 is 2cm longer than new. The apparent extra length comes from guides getting chewed though usually. In rare occasion that will be followed by the chain actually coming off a toothed sprocket. At this point usually very quickly chews through the chain covers, a jam and breaks the chain and some bent valves.

Oh: loss of oil pressure due to low on or pump failure will cause loss of chain tension also.

I havent looked at it yet but my guess is poor quality on the chain, have seen some with failed chains earlier but not on a bmw. Im going to remove the valve cover and timing cover and inspect what could have gone wrong here.

On the m62 the chain can get longer if it chew up the guides, but on the n62 I dont know.

It has not "derailed" because it ran just fine except from chains rattling and out of spec on the timing (kinda obvious) and a bit rough idle, I checked vanos solenoid to start with because they could get clogged and found that issue with chain chewing threw the solenoid.

Getting my hands on the car this weekend to inspect what has happened. Hopefully something easy but I think I have to replace chains, guides, tensioner etc...

On the M62, the normal progression is;

1) loss of tension at the tensioner
2) chain will loosen and slap the bottom chain guide when you drive over a bump
3) the brittle plastic will shatter and end up in the oil pan
4) this adds a significant amount of apparent length to the chain
5) tensioner can no longer keep the chain tight at all
6) chain will slap anywhere and break more of the brittle plastic
7) tensioner will bottom out and can't even hold chain taught at all
8) the spring pressure of the intake valves on bank one will "snap" the bank one secondary timing chain "advanced" and that after the obvious rattle sound is the typical confirmation of chain guide failure.
9) if left long enough, the chain will get enough slack it will hop off a sprocket, and mass destruction happens.

The N62 has a solid chain guide design that doesn't usually shatter like M62 so I'm very curious to see what happened to allow this to happen. I'm guessing chain guide broke to give enough slack and allow the chain maybe to take a shorter path around a corner that used the solinoid as a make shift chain guide.

It's really a miracle something far worse didn't happen.

Query: why was the tensioner replaced 30k km ago? And how many km on the odometer now? My consern is that something done during that repair caused the lack of oil/tensioner pressure that usually is the start of this type of failure.

Well I bought the car from a man last year who had bought the car with broken vanos and he has replaced the vanos and reset timing just to see if he was able to fix the car.

It has worked just fine until last week when I heard the strange sound and I thougt it was the waterpump on the way to fail. I don´t know why they changed the chains, tensioner etc but something must have happened. I think the odo is about 18700 swedish miles.

There was a lot of debree from the broken solenoid and chain guide in the filter of the upper vanos solenoid.

I dont think there is lack of oil pressure in that case it should have jumped the vanos sprocket, there could be a broken link on the chain to have seen that on one car before. Well it will be interesting to see what has happened.

https://uploads.tapatalk-cdn.com/202...bee9dd731b.jpg

A peek inside shows the chain nowhere near the solinoid but inline with it.

The only way I can see the chain hitting it is if a large piece of chain guide is missing to allow enough slack that the chain could whip from momentum into the inside somehow taking a sharp corner. Bank one or two and which side of the solinoid was chewed into?

I'm very curious. It's amazing the chain didn't bind/break. That's pretty lucky.

Check your tensioner vs OEM style when you do you recovery. Also other things like if like M62 there is that oil check valve or anything that could have blocked proper oil flow. The chain tensioner applies a shit ton of force compared to the little spring that just holds it until oil pressure builds.

Bank 2 and the intake side on the solenoid was chewed up. Its the lower solenoid that has been damaged.

Bank 2 and the intake side on the solenoid was chewed up. Its the lower solenoid that has been damaged.

So I remembered watching a Russian video with English voice over of start to finish assembly of an N62. Everybody should watch just to be awed at the enginerding.


https://youtu.be/UTdCUJEw5lM

But I was hoping to see a better look at the timing chain arrangement;

https://uploads.tapatalk-cdn.com/202...c7f0dc7f2b.jpg

You aren't going to find a better view with the lower timing cover on!

https://uploads.tapatalk-cdn.com/202...d292984948.jpg

Here's the blow apart from real OEM or similar.

If the chain is still turning and the engine can still turn over; first that is a miracle! Definitely quit while you are ahead but here's my best guess with the new info I have.

Notice how close the chain gets to the vanos solinoid socket: mere mm away.

My bet is that the bottom chain guide (yellow arrow, part 7) disintegrated or broke free, allowing the bottom part of the chain to pull straight from the crank sprocket to the exhaust vanos. This gave the chain enough extra apparent length and the tensioner guide was pushed much farther in than design and literally chain sawed though the side of the vanos cylinder socket.

This is not great news because it means at the very least some alumaweld rebuilding of that vanos socket will be required. (though actually the pressure is low enough JB weld should work).

The N62 chains are maybe half or 60% the length of M62 and that onky had about 8mm stretch over 170,000 miles so it's really not possible stretch is part of the equation.

The beefy solid guides have practically eliminated the M62 type guide failure that is so well known in X5 circles. This is the first case I've ever seen actually.

I'll be very interested to see details of what happened to part 7. And I'm a little surprised if I'm correct that the tensioner guide had enough over-run to push the chain through part of the head, it should definitely have a stop so it's maybe more likely the weight and momentum of the chain just developed a loose loop of chain that came down to cut the vanos solinoid socket.

I think that's my updated theory: the chain was loose enough to come free from the tensioner guide and whip into the solinoid socket.

On the particular N62 in the video it shows two part chain guide that could self destruct and that is the top suspect that could give enough chain slack that could still run the engine and also cut into the solinoid socket.

I'm very very interested to see what actually happened hope you can look inside soon.

I think the vanos socket is just fine because it is inside of the chain. My suspission is also the no 7 or that no 16 came loose. But before I have taken it apart I have no clue just guessing.

I dont think chain guide 10 has a mechanical stop it´s actually quite similar contruction as BRP has on the rotax engines it's the chain that is the stop.

Well I think I have a couple of hours of dissasembly, need to remove bottom pan, cooler front etc... I will try to change the chains and guides with the enginge in the car but I dont know if it is doable, time will tell. The tensioner on passenger side is my biggest concern right know there is not enough room to take it out.

There has to be enough room to remove bank one tensioner.

The M62 the spacing is bad the AC compressor is in the way.

On closer inspection it does look like the chain does miss the socket. That's very good news.

Dissasenbled everything in the front this evening, so the V is really accessible know. I think I will remove the generator ac pump and do a not workshop proffessional solution on the timing chain tensioner on bank 1 ;) The mig has to do some work after this operation... If I do that I will save a lot of hours.

Well seems like the guide has snapped or a chunk came loose from it. Look at the tensioner it´s on the backside of the guide therefor it was possible for it to chew threw the solenoid. Interesting fault acctually. This could have been a lot worse with broken valves and severe damage on pistons.

Wow I was prepared to see much much worse. Looks very recoverable.

https://uploads.tapatalk-cdn.com/202...1af325c4b5.jpg

I was surprised to see any of part #7 at all. https://uploads.tapatalk-cdn.com/202...6c99cc3d0c.jpg

https://uploads.tapatalk-cdn.com/202...2521adebca.jpg

Looking at the reference photos looks like you just had the ala M62 chain guide self destruct where the plastic shoe portion shattered and went into the oil sump.

I would be willing to bet the tensioner was the cause though.

Do you know if the tensioner was replaced with the chain/guides? Havimg done a couple guide replacements, I'm betting if you aren't changing the chain you could probably change the guides without redoing the timing. (if vanos left cogged to the chain you shouldn't need to re-set the timing) just thinking out loud.

Keep posting I'm rooting for you I am quite sure you caught this just in time to save the engine and it's not a huge fix from this point.

Well I think I need to change the chains and guides and tensioners, i guess I have to redo the timing to. I have the tools so not a big problem.

Finally I have some stuff loose to see what has happened on drivers side I actually found the piece that was missing and im wondering if I could have broken it when I took the valve cover apart.

On the passenger side the timing chain seems to have streched. Propably faulty tensioners to and has started to chew about 1 mm on the solenoid not that much but enough make me wonder if there has been cheep china shit chains in this beamer. Both tensioners are bmw oem. I don´t know if they changed the tensioners but the spring in them has verry little pressure.

Im taking down the oil pan another day and has to do a pick list of parts I could need. Did a leakdown and I dont have any bent valves, but it was hard do do because the timing is a bit off...

I sure as hell caught this just in time.

In your pic above, the alternator bracket is in place. Don't you have to remove it to get the cover off?

That looks like a lot of chain stretching.

The alternator bracket is loose had to pry it a little to get the chaincover loose. But you need to dissasemble subframe & front diff to remove the oil pan. Yes the chains are stretched a lot. Had a huge amount of luck that the valves didnt get bent.

OK. So you do have to loosen the front diff and release the bolts on the side of the engine mount bracket. I was hoping you found a better trick :)

FYI.
The old timing guide have been superseded by newer and longer ones on CYL5-8. So is the lower plastic one in CYL1-4.

I am wondering if the "stretch" is because the material that the chain is sliding on has broken off or is it really the chain.

Also saw the the lower timing guide on CYL5-8 has its tip broken off. This is the 4th N62 with the old style timing guide I've seen that has the tip broken off.

Removing and replacing guides on CYL1-4 is a pain as they do not fit without surgery.

I did find a better trick ;) Removed all bolts except one, the one behind the front diff I released until it touched the diff then I gently pryed the alternator bracked a bit to get the cover out. Going to change both timing chains guides and tensioners. I have found more plastic pieces in the oil pan probably from a previous breakdown. It´s a serious amount of work to do on this v8:s... If I ever do this again im pulling the engine out. Or atleast remove the subframe directly.

:thumbup:

Since you are this far deep into this teardown, if they have not been changed before, I would suggest you consider changing the alternator bracket gasket (12317507808) and the coolant pipe (11141439975).

After all this, you'll have a bullet proof X5. :)

I've never seen a chain stretch significantly. Please take a picture.

https://uploads.tapatalk-cdn.com/202...4de9429a0b.jpg

This is a 180,000 mile chain from M62.

Since only one chain it's much longer and this one is only maybe 7-8mm longer out of close to 2000mm.

If the chain actually stretched It would be the first time I've ever seen it.

+1
Great idea to do now.

Enjoy that mouse eared bastard, I did[emoji2959]

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+ 100


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Yes they where at the picklist just waiting for the parts to arrive ;)

Yes I will take a picture and compare the chains. It certainly looks like they are streched but it could be the guides that are completely ruined. I have not removed the chains and guides yet...

N62 misfire
 

Without some absolutely amazing defect I can’t imagine a chain actually stretching. The tiny amount is “Stretch “in the chain that I replaced it was certainly just wear at every pin .

On the M 62 with maybe almost a 2 m long chain it was only about 8 mm longer than new but it felt more like an inch because of the guides being gone

Yes I agree with that i've only seen really stretched chains on a VAG 1.3l engine and a chinese atv.

Hello folks, well the x5 is alive again, the timing chain was almost a link longer than the new ones. Perhaps there was longer chains in early n62 engines because the guides was replaced with a new type. Made it without removing cylinderheads but I had to cut the guide bolt on bank 1 about 4mm to get them in there.

The old guides fell apart just looking at them so I was really lucky, I did get 2 fault codes though on one coil and zk10 battery ignition switch (srs). The coil was an easy fix the rubber on it was broken so the spark flew all over the cyl head. But the zk10 code is anoying don´t think I could have broke the explosive charge on the battery terminal... Only removed negative terminal.

Any suggestions on that zk10 fault code except from 2ohm resistor?

Check your grounding cables...

They are all in place already checked. The fault code is for battery + terminal but it is not blown but resistance to high!

Resistance high across the bst? If you can crank, what kind of voltage drop if you measure from cig lighter to B+ under the hood?

Will do a check as soon as I get the new coil. The fault code is "11 ignition circuit zk10 / safety battery switch 1"