[Josh-PA]

Hi All,

I've had an issue with my 2011 e88 N55, no mods, 145k miles, for a while now that seems to finally be getting a little worse.

At cold start up (first time of the day, engine at ambient temperature) the car starts quickly without issue, but will have a 'stuttery' misfire for about a minute until it warms up a bit. On a very rare occasion (like one out of 100 starts) it will stall, but start right back up. Until recently this would not trigger any codes, just a couple of misfires then everything settles in fine.

For about the last 3 weeks, I am getting a check engine light on about every 3rd start with the following carly codes:
002EFE Combustion misfires several cylinders detected
002EE2 Misfire, several cylinders, damaging exhaust gas after starting up
002F0(X) Misfire, Cylinder X: Detected - i get individual codes for each of the six cylinders
002Ef(x) Misfire, Cylinder (x): damaging exhaust gas after starting up.

The cylinders listed are different on the various times I pull the codes, but usually ~3 cylinders are listed. The last code I pulled had cylinders 1, 4 and 6 listed. The time before that it was 3, 4 and 6.


The coils and plugs are OEM and relatively new (25k miles) and since it is happening on all or almost, I'd be surprised if that is the root cause. I did move some coils around and it didn't change anything.

The research I've done so far suggests maybe leaking injectors (they are original), but would it make sense that they are all leaking a little? I thought maybe HPFP, but it doesn't make sense that after a minute of warm up everything runs great. This one has me stumped and I'd really appreciate any help, suggestions or things to try.

Thanks in advance - Josh

I wasn't sure the best place to post this so I could visibility from N55 users across Exx platforms. If it should be moved, please let me know.

[Josh-PA]

just giving this one weekend bump to see if anyone experienced anything similar. I'm going to pull the plugs to see if they're wet and probably go with the idea that the injectors are old and need replacing. Would love to hear other people's thoughts before just tossing parts at it.

[RockCrusher]

Originally Posted by Josh-PA

Hi All,

I've had an issue with my 2011 e88 N55, no mods, 145k miles, for a while now that seems to finally be getting a little worse.

At cold start up (first time of the day, engine at ambient temperature) the car starts quickly without issue, but will have a 'stuttery' misfire for about a minute until it warms up a bit. On a very rare occasion (like one out of 100 starts) it will stall, but start right back up. Until recently this would not trigger any codes, just a couple of misfires then everything settles in fine.

For about the last 3 weeks, I am getting a check engine light on about every 3rd start with the following carly codes:
002EFE Combustion misfires several cylinders detected
002EE2 Misfire, several cylinders, damaging exhaust gas after starting up
002F0(X) Misfire, Cylinder X: Detected - i get individual codes for each of the six cylinders
002Ef(x) Misfire, Cylinder (x): damaging exhaust gas after starting up.

The cylinders listed are different on the various times I pull the codes, but usually ~3 cylinders are listed. The last code I pulled had cylinders 1, 4 and 6 listed. The time before that it was 3, 4 and 6.


The coils and plugs are OEM and relatively new (25k miles) and since it is happening on all or almost, I'd be surprised if that is the root cause. I did move some coils around and it didn't change anything.

The research I've done so far suggests maybe leaking injectors (they are original), but would it make sense that they are all leaking a little? I thought maybe HPFP, but it doesn't make sense that after a minute of warm up everything runs great. This one has me stumped and I'd really appreciate any help, suggestions or things to try.

Thanks in advance - Josh

I wasn't sure the best place to post this so I could visibility from N55 users across Exx platforms. If it should be moved, please let me know.

Did the symptoms appear concurrent with a change in what fuel you use? Not saying bad gas is the problem but generally the recommendation is if the engine reacts unfavorably to some brand of fuel to change brands.

Misfires description suggests an overly rich mixture or incomplete combustion.

I'd use a suitable OBD2 scan tool/code reader to monitor coolant and air intake temperatures at cold start and after.

What you are looking for is a disagreement from one or both sensors and what the ambient temperature is. With rich misfires this suggests if there is any error in the temperature reading it is on the low side.

I had a VW Golf TDi (diesel) manifest cold start issues and found the coolant temperature sensor temperature reading elevated over ambient. I don't recall by how much but clearly wrong. Had the car in and had the coolant temperature sensor replaced and cold (and warm/hot) starts were fine afterwards.

A check of fuel pressure pre engine start, during engine start and after would eliminate a fuel (over/under) pressure condition.

For leaking injectors one might consider having the injectors removed and put into an injector cleaning machine and after being subjected to a cleaning the spray patterns would be checked and and volume would be measured to ensure all injectors were performing up to spec and all were the same.

The injectors *might* not be leaking but the tips could be fouled some. This can negatively affect the fuel spray pattern which can result in sub par combustion.

You can clean the injectors in situ. If Chevron gasoline is available where you are use Chevron Supreme 91 (with Techron). If Chevron gasoline is not available you can buy Techron at the auto parts store.

Use Techron according to the directions on the bottle. Best to add the proper amount of Techron to a tank that is not full so fuel can then be added to fill the tank and in doing so helps ensure the Techron is evenly dispersed in the fuel.

Regardless of if the Techron helps or not generally a 2nd treatment is recommended. The cost of the Techron is low enough I'd throw money at 2 treatments before biting the bullet and having the injectors out for a cleaning.

[Josh-PA]

RockCrusher

Thanks for the thorough and detailed response. I hadn't thought of mixture issues, I'll check out temp, o2 and maf sensors as well.

[Tejas1836]

If it were my vehicle, given the symptoms and coil milage, I would first replace the plugs & coils [upgrade], inspect coil wires/connectors
ETA: run Techron or Redline through it as mentioned above

[RockCrusher]

Originally Posted by Tejas1836

If it were my vehicle, given the symptoms and coil milage, I would first replace the plugs & coils [upgrade], inspect coil wires/connectors
ETA: run Techron or Redline through it as mentioned above

OP states plugs/coils (OEM) have 25K miles. While a plug or coil could go bad in that number of miles (or less) that a number of them would go bad is kind of rare.

But a red flag is OEM. I prefer OE (original equipment) aka coils/plugs with *factory* part numbers. Too often I've come upon threads what basically arise because non factory parts were used and proved to be unsuitable.

Also, the OP states he moved coils around with no change in the anomalous behavior.

OTOH a DIY auto mechanic is at a disadvantage when it comes to full on diagnostic tools and experience and training.

So firing the parts cannon at the symptoms sometimes (sometimes) can be called for.

[Tejas1836]

Originally Posted by RockCrusher

OP states plugs/coils (OEM) have 25K miles. While a plug or coil could go bad in that number of miles (or less) that a number of them would go bad is kind of rare.

But a red flag is OEM. I prefer OE (original equipment) aka coils/plugs with *factory* part numbers. Too often I've come upon threads what basically arise because non factory parts were used and proved to be unsuitable.

Also, the OP states he moved coils around with no change in the anomalous behavior.

OTOH a DIY auto mechanic is at a disadvantage when it comes to full on diagnostic tools and experience and training.

So firing the parts cannon at the symptoms sometimes (sometimes) can be called for.

Like I said, if it were my vehicle...

[Josh-PA]

Just to let everyone know I'm not ghosting this thread. I've been travelling for work and haven't had a chance to dig into the issue much more. Before posting the question, i did add a large bottle of injector cleaner on a half empty tank of gas and drove it pretty hard to push the cleaner through for about 15 miles. I then filled up and have driven about 1/4 of that tank so far. I think I noticed a pretty big improvement on cold starts, but not enough opportunities to see if it is really improved or not. I plan on getting mostly thought this tank of gas, add another round of cleaner and see how it goes for a week or so. If it isn't fully fixed by Christmas, I'll have some time over the holidays to dive into it further with the recommendations provided above. I'll close out the thread with the solution if/when I get it repaired.