hln a55

Hi all!! I've been lurking as a guest for some time now and I wanted to join, say hello and maybe ask for some assistance if possible.

I have an 01 E55... 40k miles only. 18 months ago I replaced the MAF, then 6 months ago it failed again. The repair shop replaced it free of charge under warranty. It is a Bosch unit.

The MAF failed again last week. The shop replaced it with a new one free of charge again but this time the error code remained. They're going to keep the car and source the issue.

Can anyone assist with what this might be? from what i've read I can't find anyone with the same issue. I have also replaced the crank position sensor (it never failed, I just did it anyhow).

The failure always happens under full throttle when you push the pedal into the "click" at the bottom.

Thanks and hope to catch up with you all more often!!!

Tony

503C43 ////AMG

This may be a long shot but do you have a K&N filter installed? The oil from the filter has been known to be a MAF killer...

hln a55

Thanks for the quick reply.... Car is completely stock including the air filter.

Fabio D

I have this issue in some M113 engines here. the problem is the throttle body unit. Star Diagnosis system sayd BAD MAF but the real problem are in the throttle body group. Tell to yor repair shop to remove the throttle body and clean them up, remove the metal cap too and sprayed with some electronic cleaner and install it again (in some cases works propperly) other cases need to replace the unit! Maybe your shop have other car or other throttle body to make a prove!

Fabio Daniel

ruBENZ

I replaced my MAF sensor at 40K as well. I habitually clean my MAF sensor at each oil change (6 - 7K miles). Currently, at 74K with the same MAF sensor. This thing likes to be clean. Good luck.

hln a55

Thanks but that wouldn't explain the error generated byba brand new MAF.

503C43 ////AMG

Did you check the throttle body unit as suggested?

hln a55

I haven't yet. The car is still at the shop so I will call them on Monday. It was a great suggestion and would seem to make sense. . Thanks guys. I'll keep you all posted on the outcome!

hln a55

Just wanted to check back and update all... The shop kept the car for a week. They checked everything again, including the wiring harness, throttle body and even the electrical charging system. In the end, the car was fine after the new MAF after all and they only charged me the $155 for my oil change and service. We did agree though that if the MAF did fail again that we would go from the Bosch after market unit to the OEM MB unit at double the cost.

Thanks all!