Hi Folks,
Im Really In Need Of Help Regarding My 02 C240's Rough Idle And Ticking Sound Comming From Driver Side When Im At Full Stop How Ever Im Not Getting Any Cel Or Any Warning Lights. I Took The Car To Few Indis Who Work On German Cars But They Were Unable To Diagnose The Problem, Since I Was Really Getting Annoyed By The Rough Idle I Decided To Take The Car To The Stealer Hoping They Could Atleast Identify And Diagnose My Problem And Guess What They Couldnt!!!!

Here is stealers report


here is a video of engin idling (sorry for the bad quality i will try to upload a better quality one as soon as i get a chance ) you can hear the ticking sound

http://www.youtube.com/watch?v=mA-pc4ramKw

just to add i have cleaned the TB and maf as well and still no difference.
air filters and all spark plugs changed 15K ago.
replaced both cats 10K ago
and i only use mostly 94 and rarely 91 gas only.

you guys are my last hope to get this thing fixed as its really getting on my nerves
thanks

 

the ticking sound is normal kinda its the purge valve on the drivers side fender mine dose it too

https://mbworld.org/forums/c-class-w...m-already.html see post # 5 for a pic (not mine)

 

thanks for the reply, is there any possibility of purge valve causing rough idle?

 

I got a rough idle when one of the tubes that connects to the purge valve came loose ...might want to check that everything is hooked up

 

thanks for ur reply i checked all the connections, everything seems to be good & nothings loose

 

This sounds like a vacuum leak to me. I haven't experienced this issue with a MB, but have with a BMW. Check for vacuum leaks on all the lines that run past the MAF on top of the engine as those are the most likely culprits. Other than that I'm at a loss.

 

shouldnt a vacuum leak throw a CEL??? i asked the stealer and they told me vacuum leaks throw a CEL

 

Sometimes yes, sometimes no. In theory anything that would make your engine idle like that should throw a code, but in practice that doesn't seem to be the case. On board diagnostics are great, when they work, but they've also made a lot of mechanics lazy.

My favorite method for running these things down is to let it idle, and start moving things around in the engine bay (I'm talking hoses, and lines) sometimes you stumble across the issue... Sometimes you get your hands dirty for nothing.

 

do you think i can find th leak my self? iv removed the TB before, i was thinking i might have damaged the TB seal

 

Trial and error findings are the only way to know your auto

 

did it idle ok BEFORE you removed the tb???

if so your problem is that

anothervac leak finding method ive used is a piece of small hose/tubeing put one end in your ear and poke around the engine vac lines if its a decent leak you will hear it

also be SURE that the hose dose not get grabbed by moving parts!!!!

 

Any vacuum leak can cause this - Should throw a fuel trim code but does not always do this.

If the purge valve does not shut off completely. It can cause this.

A chattering TB actuator can also cause this. It does not throw a code & replacement of the TB is the only fix.

 

I think we have a consensus! Contact's suggestion is spot on, isolating the sound with a tube works really well. I have used a shotgun mic and headphones before, and that works well too, except you hear so many mechanical sounds that you start worrying that your engine might be falling apart.

 

thanks every one for ur replys
here is better video of my running engin during the day
http://www.youtube.com/watch?v=VX_jeF0zvUQ

 

so that purge valve is the thing thats making that ticking sound?

 

yup sounds JUST like mine mine comes and goes thru

 

some how that ticking sound is louder in the cabin, r u planing on changing your purge valve?

 

Mine clicks a bit. See this...
https://mbworld.org/forums/c-class-w...-its-part.html
it has the part number.

 

Replacement will shut it up. You can also try a rubber pad in the mounting.

 

mines louder



wait thats bad

 

hehe
r u planning on changing that damn thing anytime soon? by any chance you have the part number?

 

no i plan to leave it until it dies if memory serves me correctly the part was like $60 i will see if i can dig up the part number for you

 

http://www.rmeuropean.com/Part-Numbe..._5C1313F8.aspx

 

nope im not changeing it till it dies

 

thanks alot bro