Hello again everyone. I really need some help here. I posted a question about the rough idle previously and found that it seemed that the problem may have been a bad vaccuum hose that turned out was a recall replacement so I took it the MB Dealer and had it replaced. I still have the same problem and the CEL is still on. I bought this car used so I'm certain there is no warranty remaining so I would really appreciate any advice on diagnosing this myself or at least being informed as to the potential problem before i take it to a mechanic. I've read on here that it could be as simple asa MAF sensor or as costly as a cylinder head replacement. What can I do myself to give me some idea before I take it to someone. I dont want to pay for a head replacement unless its absolutely necessary.

 

In this case, in my opinion, the best thing you could do for yourself so you don't end up playing the parts replacement game, is to have somebody diagnose the problem before you ever spend a penny on parts. First, see
if there are any codes coming up with a code reader. Most of the auto parts shops will do this for no charge, since they are in the business of selling parts. At least they do where I live. Many independents will also. Then, if you don't have any luck there, I would take it to a reliable independent shop that specializes in MB, not a dealership.
Tell them you only want to know what the source of the rough idle is, whatever it is. Then at least you can make
a decision how you want to repair the car, and who's to do it....either them or somebody else. Guessing is only going to cost you more money. My opinion.

 

I agree.

 

Thanks guys.

 

HAve them do a compression check then check to see if the control module needs a software update.