[ponch]

Hi everyone, sorry for yet another MAF post.

The E55 is still new to me, only owned 3 months and 1500 kms driven. It has approx. 75000 kms (47000 miles). While taking it to my indie last Saturday morning (to schedule tranny service, I figure it's 9 years old) got a CEL on the way under moderate acceleration. Car lost power instantly, like going into limp mode. Codes were p0300 and p0303, cylinder 3 misfire, and the cylinder did shut down. So we figure either wire/coil pack/plug for starters, have a quick look at cylinder 3, but didn't pull anything out yet. No other stored codes, I was specifically looking for MAF codes as I am suspect of the MAF and even cleaned it two weeks ago. I have cleaned MAF's on my wife's previous W203 C240.

Reset codes and went for a ride w/ mechanic - no codes. Car pulled much harder and gas mileage improves to 12.0L/100 (19mpg) from 15L/100 (15mpg) in city traffic. Since Saturday, no CEL has reappeared, although I have been waiting for one. Shifts however are strange. Under normal acceleration, they are fluid and smooth. Under heavier acceleration the car almost feels to hold back then power comes all at once and gear seems to hang at 6500 rpm until shifting. Shifts are somewhat jerky at that point, but the car still accelerates decently, but not great. Gas mileage has worsened.

Any idea's? Just change out the MAF and do the tranny service? I am planning to pull the plug/wire tomorrow, but thought to pose the question first.

BTW - while at the indie, caught a ride in a CLS 65 AMG there having summer wheels put back on. Not a fan of the CLS, but did that engine ever impress me. It sounds wonderful!

Thanks in advance,

Rob

 

[ponch]

Thanks for the advice.

Due to limited time this weekend, I did not have a chance to pull the plug/coil/wire in cylinder 3. I did get to the battery reset Saturday afternoon, and was I ever glad I did it.
After reconnection, the car was fantastic. I only drove it for approx. 10 minutes, but it had great response, no hesitation and smooth shifting all along the rpm ranges. Torque was outrageous, and I didn’t drive it hard in fear of the trans fluid. Drove much better than I have yet to experience and there were no hanging or jerky shifts, although I will proceed with the tranny fluid change, which is scheduled for next week. Drove it again on Sunday, no changes, still strong. I will monitor to see if the car reverts back to “grandpa,” as msiumng states, but I still need to inspect cylinder 3 coils/wires/plug. I find it odd however that since the CEL last week, the problem has yet to reappear.

Rainer, the MAF is located at the rear of the engine under the air box. There is a sticky in this forum under DIY on MAF cleaning that is very accurate and well detailed along with many, many MAF posts here to help if you search them. I’ve probably read all of them before posting my issue. You will need to remove the airbox to access the MAF. I suggest searching the forum for instructions if unsure how to remove either the airbox or MAF. The MAF assembly itslef is black and cylindrical in shape with the sensor in the centre of the unit. If cleaning, please ensure that you use MAF Cleaner. Some suggest electrical contact cleaner I believe. I regret that I do not have the sticky steering wheel button issue, but I can appreciate your frustration with it. It seems us E55 owners are pretty meticulous, if not anal with our cars. I found a couple creases in my rear seat as a result of myy daughters child seat and want to replace the bench! You may wish to try the battery reset also. I was completely baffled with how different the car was after completing that.

 

[ponch]

Star Garage,

Thanks for the response. I have been monitoring closely since the code, none have re-appeared, but I will address it. As for the MAF, I’m just going to change it.