Missing during cold start

[seagrasser]

Hi guys. Looking for some help in diagnosing a misfire during cold startup in the morning.
Car details: 2009 e82 (N54), 55k miles, FBO, JB4 running custom map 6 (map 1 for now until I can figure this out), original injectors, no leaks at turbo, no wastegate rattle.

What I know: Valve cover has developed crack just forward of PCV system. Oil leaking into valley between cylinders 3/4. I know this is a new development since I replaced the valve cover gasket and plugs earlier this summer.

What I have done so far: Put in new set of plugs (visible oil on threads on cylinders 3 and 5). Changed all of the ignition coils (Delphi). Ordered new valve cover and updated PCV valve from BMS. Walnut blast done last winter.

Planning on getting the valve cover on this weekend but want opinions.

Question: after replacing plugs yesterday, I am still getting misfire in the morning at cold start. Is this a symptom of the valve cover being vented to atmosphere, or are my injectors shot/fouled now?

Want to get the car healthy again, so what do you guys think?

[Smitty925]

I am having a very similar issue as well. It misfires only on cold starts. I've changed all spark plugs and coils but no improvement either. I hope it's not the injectors!

[seagrasser]

Originally Posted by Smitty925

I am having a very similar issue as well. It misfires only on cold starts. I've changed all spark plugs and coils but no improvement either. I hope it's not the injectors!

I would check your valve cover and vacuum lines. Compromising the vacuum can cause this (as well as faulty injectors).

[E82MSport]

When is the last time you had your intake valves walnut blasted?

[Smitty925]

I had my valves walnut blasted just 2 months ago

[seagrasser]

Mine were blasted about 8 months ago

[6MT_Addict]

Have you replaced the cracked cover yet? Probably the cause

[seagrasser]

Valve cover is replaced and reset the adaptations. Fixed 95% of the problem. Still have a little hesitation at cold start. Think injectors are next, but at least I have some time to diagnose them.

[Dat Aus]

Clean the VANOS solenoids.

http://www.n54tech.com/forums/showthread.php?t=20650

[seagrasser]

Hmm, appreciate the advice, but I have not had one VANOS code yet. Guess it couldn't hurt.

[Dackelone]

Originally Posted by seagrasser

Valve cover is replaced and reset the adaptations. Fixed 95% of the problem. Still have a little hesitation at cold start. Think injectors are next, but at least I have some time to diagnose them.

Pull off the valve cover and start the car up in a dark garage. Spray down(with a mister bottle) the injectors and look for arcing.

Did you use BMW spark plugs? They say "BMW-Bosch" on them. The Bosch aftermarket plugs can cause a misfire.

I would also spray down the valve cover with NON-flammable(VERY IMPORTANT!!! CRC makes a non flammable) Brake Cleaner spray. When you hose down the intake tract... (with the engine running) IF the engine starts to die... you've found the problem.

I would also look at all the vacuum lines around the valve cover(above the turbos going to the WG solenoids) and the vacuum line that runs around the oil filter housing. They are known to get brittle and leak. Basically tug on the vacuum lines and see IF any are broken.

I don't think a VANOS solenoids is your problem.

What you CAN DO is read the idle speed out from the OBDII port... when you feel the miss... see IF the idle speed goes down. IF so you know its something on the primary ignition side(coils, plugs). IF the idle stays steady, but you FEEL the miss. Then its something on the fuel side. Like... a bad injector or spray pattern or fuel pressure.

Good Luck,
Dackel

[Dat Aus]

Originally Posted by seagrasser

Hmm, appreciate the advice, but I have not had one VANOS code yet. Guess it couldn't hurt.

There are numerous people in that thread who reported small misfires and rough idling when cold that were resolved by cleaning/replacing VANOS solenoids. I'm not saying it's definitely the cause of the problem but for the 30 minutes of work it takes to clean them, it's definitely worth a try before you replace the injectors.

[Jeff@TopGearSolutions]

Originally Posted by seagrasser

Hi guys. Looking for some help in diagnosing a misfire during cold startup in the morning.
Car details: 2009 e82 (N54), 55k miles, FBO, JB4 running custom map 6 (map 1 for now until I can figure this out), original injectors, no leaks at turbo, no wastegate rattle.

What I know: Valve cover has developed crack just forward of PCV system. Oil leaking into valley between cylinders 3/4. I know this is a new development since I replaced the valve cover gasket and plugs earlier this summer.

What I have done so far: Put in new set of plugs (visible oil on threads on cylinders 3 and 5). Changed all of the ignition coils (Delphi). Ordered new valve cover and updated PCV valve from BMS. Walnut blast done last winter.

Planning on getting the valve cover on this weekend but want opinions.

Question: after replacing plugs yesterday, I am still getting misfire in the morning at cold start. Is this a symptom of the valve cover being vented to atmosphere, or are my injectors shot/fouled now?

Want to get the car healthy again, so what do you guys think?

A crack in the valve cover would cause poor idle at cold start.

Originally Posted by seagrasser

Valve cover is replaced and reset the adaptations. Fixed 95% of the problem. Still have a little hesitation at cold start. Think injectors are next, but at least I have some time to diagnose them.

It could be injectors at this point.

Did you have any fouling of spark plugs when you pulled the old ones?

Do you smell fuel at cold start?

[seagrasser]

Originally Posted by Jeff@TopGearSolutions

It could be injectors at this point.

Did you have any fouling of spark plugs when you pulled the old ones?

Do you smell fuel at cold start?

Car is generally running much better with a hiccup here or there, so valve cover replacement solved much of the issue.

Spark plugs were fouled from oil seeping down the threads. Am guessing this could be an issue for the injectors as well.

Smelled a lot of fuel at start before I replaced the valvecover. Now only a faint trace (recall I have DP's).

My assumption now is that there may be something minor going on with the injectors, but it will need to get worse to diagnose/address.

[mxchris727]

Originally Posted by Dackelone

Spray down(with a mister bottle) the injectors and look for arcing.

I would highly advise against this. The injectors are NOT water resistant. I learned the hard way while washing the engine with the cover off.

[Dackelone]

Originally Posted by mxchris727

I would highly advise against this. The injectors are NOT water resistant. I learned the hard way while washing the engine with the cover off.

I said to "mist" the coil packs... NOT hose them down. As with all things... a little common sense goes a long way. Bottom line is IF you don't feel comfortable working on your own car... take it to a pro.

[mxchris727]

Originally Posted by Dackelone

I said to "mist" the coil packs... NOT hose them down. As with all things... a little common sense goes a long way. Bottom line is IF you don't feel comfortable working on your own car... take it to a pro.

I was misting them when washing.

[1Pirate]

I just had to have my injectors replaced. There is a TSB on this issue with cold starts and misfires related to the injectors. My issues matched the TSB including the codes that I was getting. I don't have the TSB with me today, but I will post the TSB number later. I had a check engine light that wouldn't go away despite trying several different things. I tried fuel injector cleaner and cleaning the MAF, but neither fixed the check engine light. And the car was running rich.

Then I tried replacing the plugs, but that only solved the problem temporarily. My problem was I couldn't just replace the three injectors in the bank with the code because the replacement injectors won't work with the older ones since they have been modified. My old injectors were index 8. The newer injectors are index 11 or 12. Apparently, index 8 injectors won't work with index 11 or 12 injectors. My car is a 2009 with the N54 motor.

With new plugs and injectors the car seems to be running fine now (fingers crossed).

[1Pirate]

Anyone else replaced their injectors?

[Jeff@TopGearSolutions]

Originally Posted by 1Pirate

Anyone else replaced their injectors?

Replaced all 6 on my car at 45K. Only about 2 were done. I like my car running optimally though.

Injectors are a common failure point.

[1Pirate]

I hadn't read about anyone really having issues with their injectors until it became a problem for me. My car doesn't get driven a lot. It only had 23,000 miles on it when I had to replace the injectors.