BConly

Ok, I'm going to tell you all that is going wrong with my '97 e420, it might be a few separate problems, or one big problem, I have no idea as I am not an auto mechanic. Heres the scoop:

I bring my car into service at an autorized MB dealer on a regular basis, and nothing went wrong until about 6 months ago. It started out as just a slightly rough idle, I didn't think much of it, as it wasn't very noticable, but it got worse over time. Instead of just being a rought idle, it began to jerk back and forth under speeds of about 3mph. Yes, at very low speeds (such as those when idling on flat ground with foot off both pedals), the car jerks back and forth and the tachometer shows that the engine revs are fluxuating more than usual. For some reason, this doesn't happen all the time, I'll usually start the car, and it'll be fine but about halfway to work, i'll stop at a light and the car will start to jerk agressivly and idle roughly. Once it starts, usually it will continue to do it until I turn off my engine, but occasionally it will stop doing it at some point.

A few weeks after it started doing it, I took it in to be serviced, they found nothing wrong and assured me that my I was immagining things. The day I got my car back, as I was driving home, the "Check Engine Electronics" light came on, and I drove right back to the dealership and showed them. They took another look and again claimed to have found nothing. They said that the sensor was just faulty, and they reset the sensor. The problems continued to occur, so I went back to my dealership and again they found nothing wrong.

Now the problem has seemingly gotten worse, it happens more often and the shaking is worse. The Check Electronics light comes on sometimes and turns itself off the next time I start my car. Also, recently, the car seems to be having a little bit more trouble starting, this could be completely unrelated, but i figure I'll tell you anyways.

Just for the record, I am a very conservative driver, I never redline, so I don't think its because I have driven the car hard. If you have any questions, please ask, i'll be checking this thread daily. If you want to talk to me in person, my AIM is BConly - i'm usually on at night from 7pm-11pm pdt. Thanks a lot!
-Peter


PS. I posted this in the e class forum but was told to post it here too. Sorry for posting it in two places, I didn't know any better at the time.

Also, if anybody could tell me a good auto shop to take my e420 in the Los Angeles area, that would be greatly appreciated. Peace out,
Peter

BConly

help plz?

suginami

Sounds like a bad mass air sensor, throttle actuator, or a bad vacuum leak - possible at the intake manifold seal.

patrick

When the "check engine electronics" light has come on there will ALWAYS be a fault code in memory! But maybe your dealer does not know what to do with the codes in memory?

Maybe you should read this:
https://mbworld.org/forums/showthrea...452#post102452

If the fault codes refer to cylinders that have been shut off, you may have bad gas (water?...).
Do you hear uncommon noises underneath the car coming from the catalyst?

Is it a "real" (official) MB-dealer?

Patrick

BConly

First of all, I always use premium gas, so I assume the gas is ok.

Yes, it is an official MB dealer, but they are dumbasses over there, so its likely they don't know what to do with those codes of which you speak of.

I don't really hear any wierd noises coming from the engine, just the revs going up and down at idle and at under 5mph speeds.

The check engine electronics light and the check engine light both went on today, but turned off the next time i started my car, just thought i'd let you know that it is still happening.

Thanks for your help,
Peter

suginami

Something is definitely wrong.

I have never heard of check engine light coming on and then going off without being reset.

In any event, you have OBD-II, and there should be a record of the engine fault code.

The scanner can also be hooked up with the engine on, and even while the car is driving, to retrieve live information.

If the dealer is having the trouble getting these codes, then you ought to find a good independent that specializes in Mercedes automobiles.

BConly

i'm gonna take it in soon with a list of all this stuff and tell them what to check myself, maybe they'll get it right this time?

darkLCD

Bconly, where do you get your car serviced at? I also think it's a bad MAF sensor (mass air flow sensor).

BConly

WI Simonson in Santa Monica. Do you have a reccomendation on where to take the car? WI Simonson is full of mechanics that probably don't even know what a maf is.

darkLCD

BConly, I sent you a reco by PM.

suginami

There is only one shop I can recommend, and he's not too far from Santa Monica. I live in Diamond Bar, and drive 54 miles each way to get there. I know more than a dozen people all over So Cal who use this shop. I even know one guy who transports his S600 from Montana to get it worked on. He had too many wrong "fixes" from the MB dealer in Idaho. He's started working on MB's in 1965 in Spain, South Africa, Steigler Mercedes in L.A., then shop foreman for Beverly Hills Mercedesm, and finally he opened up his own shop. And his labor fee is only $60 / hr:

http://www.mercedesshop.com/shopforu...hlight=enrique

BConly

thanks for the reccomendations guys! i'll give these guys a call!
Thanks a million,
Peter C.

Lafool

I hope you find out what happened to it because mine does the same thing! They said they could not find anything wrong with it and sent me on my way.. They have already replaced the dashboard climate control and the speedometer and they think it was a short in the system...HELP!!