E70 misfire on cylinder 1
 

I would do valve adjustment before changing injectors.

Wouldn't the valves affect more than one cylinder? It has only ever been misfire on cylinder one. I don't hear any clicking coming from the engine.
Trying some fuel injector cleaner before I rip it apart. Just got this vehicle so I don't know the history.


Sent from my iPad using Tapatalk

Skip the valve adjustment....

Miles? Age?

Do you have BMW software and cable? I believe there may be a way to look at injector timing, etc, to see if something unusual is going on there. There is a gernman terms called "Running Unrest".. a measure of the acceleration of the crank after each firing, a measure of unbalanced cylinders. Ive used this to track down bad coils.

NOTE. I had a bad coil in an s62, when I switched positions the problem moved but NOT precisely. This is because the algorithm is inductive (it looks at crank motion, and decides what coil must have caused the lack of accel) ...not an email from Cyl 1 saying "i am bad"... your issue may be the coil prior to that cyl (in the firing order) causing the DME to misdiagnose the source of the misfire... by finding the firing order and choosing your coil swaps, you can get better diagnostics

87000km 2007
I switched the coil from 1 to 5(other side of the engine on the front) I wonder if I would have a different code if I changed it with number 3?? 5 does fire right after 1.
That might be an interesting test. Thanks for that info.

I have BMWhat app for android and Dash Commander for reading codes

BMWhat has a section under Parameter that has a "Running unrest filtered"
for each cylinder. Values varied for each cylinder evenly across the 8 cylinders. Not sure what the values should be but they all seemed the same 0-181/sec.

If I let the car idle in the morning for 2 minutes the misfire doesn't occur.

have you moved the spark plug around?
have you replaced spark plugs?

I did move coil and plug from cylinder 1 to 5
Plugs looked clean. Going to try and switch them to cylinder further away in the firing order to see if the code changes.


Sent from my iPad using Tapatalk

Almost sounds like contact related issue.
As in the voltage is getting too low or the contact connecter that is plugged into the coil is loose (I mean the metal part internal to the connector).
Do you see any oxidation on the connector?

Going to have another look at the coils and connectors tomorrow.
This morning I did have another light come on right after startup. It was a traction control abs light malfunction. I had no power steering until I read that if you turn the steering wheel all the way left and right and it said initializing and the light went away. I also read that this and other warning lights may be a result of a weak battery. Could the misfire be caused by a weak battery? Doubt it, but don't know much.


Sent from my iPad using Tapatalk

Looks like you are looking at a failing battery.
However, if possible also take a brief look at your alternator too.

Ok my problem has been solved.
I replaced cylinder 1's fuel injector.
Upon removing passenger side bank of injectors it was clear that cylinder 1 was not like the others. The other injectors were dry and cylinder 1 was wet with a black buildup on the tip.

My misfire is gone.
I want others to know that the acceleration hesitation at low rpm is also gone. In my search for a fix I came across a lot of people with a low rpm hesitation that seemed to baffle many people. Most people were pointing at the VANOS but I tried cleaning vanos solenoids with no luck. Turns out it was a faulty injector.

Pulling the injector was quite easy and maybe a 4 out of 10 for a DIY job. The wiring harness on the N62 can be loosened enough to access the rear bolt that holds on the fuel rail. You will have to take off the Valvetronic motor, not such a big deal and no need for BMW tool to reset. It resets itself just don't start the car right away and screw it back in when installing for it to find its endpoints. Search and read about this before removal. Not much else has to come off to get the injectors out.


Ok nevermind... after 4 days of no misfires. This morning is -25C and I yet again have a misfire on cylinder 1 and the hesitation is back..
:banghead:

Who is directing the troubleshooting??? A qualified BMW master tech? If not, someone is pissing away money. IMO.

That running unrest test is a key. Post up the results before AND AFTER you moved coils. At idle and at say 2000rpm.

Did you know the firing order??? I believe 1-5-4-8-6-3-7-2

So you basically moved that one notch over. Im not sure how this DME traps misfires, but Id want much more separation before spending $$$ chasing zebras.

GL


('Zebras' a reference to diagnostic medicine- "when you hear hoof beats dont think zebra")

You remember as a kid jumping into a pool thinking you were in the shallow end and ending up gasping for air as your head goes under the water. Thats what this is like. No Master BMW tech involved...Yet. I thought maybe coils, spark plugs or injector... Easy fix. This eccentric shafts and VANOS problems get very complicated.
I know the running order. Its not a spark issue. I swapped coils front to back.

Disabling VANOS by disconecting VANOS solenoid or disconecting eccentric shaft sensor causes the shaft to return to a default position witch maximizes intake valve lift. In this position the car runs fine with no misfires, or stumbling at all!!! (Just a crappy CEL) I think the misfire is caused by insufficent opening of the intake valve which lead me to the intermediate lever.

The whole idea of reading and learning is to NOT piss away any money. If I took this car to the dealer they would have changed coils and plugs, then maybe injectors, which would have cost me more than what I have spent. The problem is most people on the internet don't know much more than swapping coils. Thats not a jab at you, it is just that I have eliminated that as a problem.

I will post some pictures from INPA once I get them maybe it will show something unusual.
Thanks for the help

Yeah, disconnecting the Valvetronic motor[s] makes the engine run like a regular engine with the load regulating done by the throttle body and not the VT. But it also works a bit restricted on power, so that can mask the problem. It is good to see what INPA says.

Sorry not sure how to shrink those pictures.
Tried hard to make the car stumble and take a picture in each section.
Cam position sensor seems off?
Knock sensor was a bit off but engine roughness didn't move?
MAF?? Will check that one again.

1. How old is the battery? When was it last replaced?

2. Can you run a VANOS functional test?

3. might consider removing the VANOS Actuators and cleaning them thoroughly. (I would do a functional test first, but since you seem to want to just do things and not diagnose, this is relatively easy.)

4. Can you scope each CPS? and maybe the Crank position sensor? On other model BMWs the CPSs are KNOWN to go bad over time leading to cam timing issues and codes.

5. that 'run roughness' seems wrong. All zero? Impossible I would think...

1. Not sure how old the battery is? Just purchased the vehicle a few months ago. Never had any issues with it cranking slow. It seems to be charging correctly.

2. Downloading DIS v57 to do a vanos check. Not sure if I can do that in inpa?

3. Vanos solenoids have been removed and cleaned with compressed air. HaHa I love working on cars and have nothing better to do. NOT.

4. I haven't scoped the CPS. Wouldn't I get a CPS malfunction if they were bad? I don't know how to do that test. Will figure it out. Are the intake and exhaust CPS the same? I think they looked exactly the same hope I didn't mix them up.

5. I agree. I am going to repeat that test again.

Thanks

BMW has an issue when voltages get low and their 'intelligent battery management' software fails to provide enough voltage to certain modules. The old days of a solid '13.4V when running' are gone. BMW actually allows the voltage to drop to avoid putting a draw on the alternator and motor during cold start. Emissions I think. (This is the reason you hear about 'short drives' leading to battery issues.) But it can also cause sporadic issues with various modules. I dont think this is likely as yours is very repeatable.

You SHOULD get a CPS error when they fully fail. But we have come to learn that they can internally degrade and lead to shifted values/signals. The DME doesnt run a complete diagnostic on every aspect of the signal: it is there or it is not there. If it is there, but distorted, you get no CPS code but distorted cam timing. Can that manifest as a misfire? Dunno.

In the E39 S62 land we just recommend replacing all 4 CPS as maintenance. Period. Why mess with a sniper-shot diagnosis, when the prepondernace of evidence points to 'you will need to replace these eventually.'

I dont know the part numbers- look them up. If different part numbers then they are different.

Finally got DIS installed and did a check on the Vanos and intermediate levers tolerances. Both tested ok. It is spring now so outside temperature is warmer. I don't get many misfires anymore... maybe once every 2 weeks. I still notice the acceleration hesitation but it is less severe. Some days there is no hesitation at all and other days it is quite noticeable.

On the days with no misfires I do notice that the car idles higher when first started. Maybe 700-800rpm and then when it warms up it drops down to 500-600rpm. Is this a clue? Temp sensors? What causes the higher idle at startup?

In DIS I did notice that the battery looks like it was replaced with a mileage just before I purchased the car. Maybe someone was trying to fix the misfires before selling the car... Who knows?

Yikes. Had the same fault this past weekend. As part of the N63 Customer Service Pkg, dealer is replacing all injectors, fuel pump, hoses, mass airflow sensor, and plugs. Fingers crossed.

Has your vehicle had this done? Even if it is out of warranty, might they cover it if it was never performed?

***NOT PROBLEM SOLVED!!!!*** 2007 BMW X5 4.8 N62 engine
keep reading below

Messing around with the DIS software I was able to read something that said "sporadic low voltage DME"
I first went to the battery to check and all connections and voltages looked fine.
I then went under the hood on the passenger side near the firewall and got down to where the DME is located. Poked around a bit to see if any water leaked into any components or looked for any faulty connections. It is a mess of wires in there!! I did unplug the 2 40amp fuses and looked at the 2 relays in the DME compartment. Couldn't find anything visually so I buttoned everything back up and went to start the car.
I thought I should check the codes before starting the car as I unplugged the DME fuse and figured I would get some kind of DME error code.
To my surprise I had "Misfire on Cylinder 1" !!! :dunno: The car did not have that code when I parked it and I had not even started the car yet.

I then came to the conclusion that there was an electrical problem with the DME that was causing my misfire code.

I went back in to the DME compartment unplugged everything and cleaned the connections with electrical cleaner. I did re route some of the wires as they were overlapping quite a bit with some large gauge red 12v wires with some of the smaller gauge wires. Unplugged the fuses and sanded the ends to make sure they have good contact and are able to transfer 12v properly.

Car has been running amazing since. No misfires in 3 weeks.
My hope is that this info helps someone out there. It is such an easy thing to check and requires no money or tools for that matter.
+1 for ARD as he set me on the right track with the post above:thumbup: Thanks

New owner here....what is the DME?
Just starting getting a slight hesitation at idle. CEL illuminated, pulled code and its P303 Cylinder 3 misfire.

Prolly gonna move coil this weekend and see what happens...

DME = Digital Motor Electronics

Engine Computer.

Google DME and BMW:

BMW Technology Guide : Digital Motor Electronics (DME)

After months and months of no misfires. Cold weather has returned along with the misfires.
Still only misfires on cylinder 1. Start the car it idles smooth, let it idle for 15-30 seconds, pull out of the driveway by the time I hit the end of the street and start to accelerate BOOM misfire and I can feel it running rough. Pull over shut the car off and turn it back on and it runs fine the rest of the day. The kids down the street at the bus stop must think I am weird stopping and starting every morning lol.
Took the car to a local shop and they did a smoke test which showed no leaks. They wanted to change coils and plugs which I declined. I have moved coils around and changed plugs already. They said maybe I need a software update and suggested I take it to the dealer to check out.
I may take it to the dealer. Just hope they don't tell me to change my coils like the other shop.

Did you find a solution to your issue?

I know this is an old thread but I've been going through similar issues with my 07 4.8l but I don't get the cylinder misfire fault. I use Carly which gives me a bunch of CAN faults. I have the hesitation and cel also. When it first started, it was the cel and just a little bit of hesitation at the throttle. Once I clear the faults, the cel goes away and it drives normal again. However, after a good few miles of driving, the cel and hesitation returns. It's gotten worse overtime as now the Cel comes back at every other startup. I changed and tested a bunch of stuff, even thought it was a voltage issue at one point, nope. Got ripped off by the stealership by replacing the IBS and negative cable. Then I replaced the alternator myself, checked and cleaned the vanos, replaced the battery, still the same. Then I replaced the eccentric sensors, which were fine, but along the way I discovered a fallen rocker arm on bank 1. I was for sure that this was the problem but it wasn't! So this weekend, I'm going to check the crank sensor and replace the dme relays and hopefully this will solve the mystery. If it still doesn't solve the problem, I'm getting rid of the POS!!

I don’t know if you have already changed the plugs but a bad/out of spec plug can cause this issue. A bad plug won’t always set off the CEL. I was able to use my scanner and look at fuel trims on each cylinder. I ended up replacing all my plugs but the cylinder that had the worst plug had a measurably different fuel trim. This was the cylinder causing the hesitation.


Sent from my iPhone using Xoutpost.com

Way before I thought about the plugs too but they all look fine. They are the original oridiums that came with the car. I only have 51k and im sure they've never been replaced before. Hm.. Maybe I'll look into replacing them too just for peace of mind. But how would plugs explain the CAN faults I'm getting off Carly. I would think it's a short due to a bad sensor. But anyway thanks for the advice as I'll look into it again, but sure hope Marky would tell us his verdict.

I didnt think a can fault could impact the engine.

Inputs to the DME are NOT 'bussed'. all direct wire. IIRC.

The design philosophy was that 'mission critical' stuff (like engine management) was separate from other communication, entertainment, windows, etc.