Glyn M Ruck

Yes - if it is a persistent misfire - not 1 in a thousand.

d1no

well i just replaced the fuel filterr.. what a pain in the *** with working under the car with low clearance and the location of the filter is akward too.. the car still runs the same and the idle goes up and down a bit.. looks like im going to have to wait for the spark plugs

d1no

a little update on this.. i couldnt find the bosch plugs anywhere local so i just ordered em on ebay for a crazy deal came out to like 5 something a plug .. today i took out the old plugs and i couldnt beleive what kind of plugs someone stuck in there.. there was 3 champion plugs and 1 autolite plug that was huge like bigger then the rest of the plugs.. no wonder the car ran like crap.. I bought my car with 55k why would anyone put crap plugs in there at 50k?? SOOO YOU GUYS WHO BOUGHT USED W203 CHECK YOUR SPARK PLUGS U NEVER KNOW!!

Glyn M Ruck

The things that ******'s do to cars. I'm sure she will enjoy a new set of plugs!

d1no

I'm with you Gyln, using proper plugs is not much more money and sure gives less problems.. I hate when people cut corners..

d1no

OK got the plugs today installed all 4 of them.. They are Bosch FR6MPP332 which is the right ones for my car correct? at first the car ran a bit better and idle started being rough again.. I reset the codes and they havent come back in the 15 min driving I did.. But when the car warms up and I drive it a bit spirited for few min and let it idle it idled perfectly and no shaking.. After it cooled of and i restarted it, the idle was rough and keeps going up and down.. so far I replaced the plugs and the fuel filter.. what could it be.. Im calling on monday to see if that hose recall has been done..

91RS

I haven't had much experience with high miles on these cars yet, but have you ever cleaned the throttle body? That's usually a source of a rough idle.

LILBENZ230

This sounds similar to Phil's (nlpamg) 05 C230 when it had throttle body problems. You should definitely look into that.

Glyn M Ruck

+1 clean throttle body & MAF while you are about it. On Phil - Our moderator's car they had to replace the throttle body to get rid of rough idle. Sometimes the TB actuator goes haywire & chatters.

Check for all air leaks - e.g. that damn hose.

Glyn M Ruck

Matt & I do it again & post over one another - LOL

d1no

Thanks Matt and Glyn I read nlpamg's thread and it does seem similar to mine and considering how dirty my engine bay seems it could be those things.. I will clean the trottle body and maf tommrow and also get some techron to add in to the fuel so it can clean up the engine a bit too.. Any other easy fixes to try?

d1no

Well i just called the dealer and it seems like there is an open recall on my car for the vent hose.. do you guys think thats what the problem could be?

I also cleaned the throttle body and idle is still weird.. is it ok if i drive the car without the air intake hose attached because that thing is filthy lol?

91RS

An unmetered air leak can and will cause a rough idle. I'd take the car in for the recall and get that done for sure.

d1no

^ I've made an appointment for next week.. Would it hurt my car if I drove it to work with the rough idle.. I mean with the new plugs and fuel filter the car seems to feel better and pulls harder than before and engine is smooth unless its idling on a cold start, there is no check engine light at the moment.

Glyn M Ruck

Fine to drive.