2.3 kompressor bad idle when cold

[nick9one1]

I'm trying to diagnose a bad idle on my c230k, and hoping someone can point me in the right direction.

Here is what I've discovered so far;

• Idle is bad when completely cold
• when warm its not perfectly smooth, but far better than when cold
• I've cleaned the MAF, and tried running with it disconnected - exactly the same.
• I cant see any obvious vacuum leaks.
• no error codes.

I'm hoping its just a vacuum leak, but the way this kompresors are designed I'm not sure if this is really possible.
non turbo/kompressor cars take the vacuum after the MAF. so when you get a vacuum leak, unmetered air bypasses the maf. From what I can see on my car, there are no vacuum hoses after the MAF. So even if air was leaking in a split hose it would still run though the MAF.
Can anyone confirm this?

this video is after about 60s second of running, just at the point the idle starts to smooth out.

https://youtu.be/lS0mL_h0OUI

 

[streethawk]

I'm trying to diagnose a bad idle on my c230k, and hoping someone can point me in the right direction.

Here is what I've discovered so far;


[*]Idle is bad when completely cold
[*]when warm its not perfectly smooth, but far better than when cold
[*]I've cleaned the MAF, and tried running with it disconnected - exactly the same.
[*]I cant see any obvious vacuum leaks.
[*]no error codes.


I'm hoping its just a vacuum leak, but the way this kompresors are designed I'm not sure if this is really possible.
non turbo/kompressor cars take the vacuum after the MAF. so when you get a vacuum leak, unmetered air bypasses the maf. From what I can see on my car, there are no vacuum hoses after the MAF. So even if air was leaking in a split hose it would still run though the MAF.
Can anyone confirm this?

this video is after about 60s second of running, just at the point the idle starts to smooth out.

https://youtu.be/lS0mL_h0OUI

Not sure if it's the same as w202 but new breathers and check valve and clean both jets under inlet where these breathers plug in is normally problem but on w202 but yours shouldn't be too different

 

[nick9one1]

thanks for that. Wasn't aware of that problem.

Is this what you are talking about? Mercedes-Benz Owners' Forums - View Single Post - How to stop MAF oil contamination (CLK 230K - W208)

 

[streethawk]

thanks for that. Wasn't aware of that problem.

Is this what you are talking about? Mercedes-Benz Owners' Forums - View Single Post - How to stop MAF oil contamination (CLK 230K - W208)

Yep. This will stop oil getting on maf too as this blockage make oil come out of rocker breather which then makes its way through the inlet.

 

[nick9one1]

I haven't had chance to do this yet.. But have had another poke around under the bonnet to see of I could spot an obvious problem with the hoses you talked about.
I can hear what sounds like a vacuum leak from somewhere under the manifold.
I might try the carb cleaner/butane trick before I take it apart.

 

[flango]

It will most certainly be a vacuum leak, also check all the piping under the Kompressor often this splits and leads to lumpy idle

 

[ahok19]

https://youtu.be/lS0mL_h0OUI

good video !!!

 

[nick9one1]

I finally got round to checking the nozzles and one way valve under the inlet. They were pretty oily, but not blocked as far as I could tell.

Surprisingly, the hoses were all in pretty good condition - not brittle or cracked, and still soft. I wonder if MB changed the type of rubber for the W203?

 

[nick9one1]

I'm still having this problem, and it seems to be getting worse.

I went ahead and replaced all the hoses and one way valve under the inlet.
This hasn't made any difference what so ever.

I had a good look at the other hoses, all seem to be in good condition and not leaking.

Any other suggestions?