Help! E55 has check engine light on
 

I was stopped at the light this weekend and suddenly the engine was rough idling... tach showed 600rpm down to 100rpm then back to 600rpm back and forth. Next morning the check engine light came on. I tried to call teleaid SOS and the technician told me it was probably bad grade fuel (?) and that I should just refuel again and in a couple days it will go away. I have always used premium grade fuel in this engine, 92 octane +. So I refueled up with mobile supreme and the car still rough idles, and STALLS when I'm at the light. However when I am cruising it is FINE, engine power feels normal and I did make a 250mi roundtrip without any problems. This only happens when I am at a STOP. Has anyone had this unfortunate thing happen and how did you resolve it?

Thanks for your comments! :confused:

Hey. I had the same problem with my 2000 E430 4Matic. I too thought it was maybe bad gasoline--NYC Metro area, must be a bad station somewhere you know. Still stalled, idled rough, etc. Dealer (Millennium, Bridgewater NJ) replaced Mass Airflow Sensor. Solved the problem. Covered by warranty. I know E430 is a different animal than an AMG, but I think dealer diagnostics would be a good bet for your beast...

Its the Mass air flow sensor. Its the same crap that happened to my E55. I dont understand why this happens to so many Benzes but at least the warranty will cover it. It is still a pain in the a$$ to give up your car for a day to get it fixed.

So is this a common problem to all or certain MB models??

mas mass air sensor problemas
 

must be an E55 issue. mine went out 2 weeks ago; same symptoms as AMGGuy's. mine went out with a "chuff" under moderate throttle at about 4000rpm, then had the same rough idle and stall at idle. car has only 17k miles, and again, fixed same day by dealer under warranty.

This bad rough idle issue do not belong only to E Class. I saw the same problem in the A and C Classes with petrol engines.
What could be the "connection" between that Air Mass Flow Sensor and the idle stabilizer? Hard to understand...

Sergio

Like Vic says, it's the mass air flow sensor. Had the same thing happen to me. It seems to be a common problem on E55's at least, maybe 430's and 320's as well.
rich
'01 E55

Thanks to all replies! I have an appointment on 3-14, I'll keep you guys posted :)

I just got my car back today from having sercive done due to the "Check Engine" light on.

The cause? Mass Airflow Sensor

Good thing it came on now, because my warranty is going to be over in about 2000 miles. :)