W203 - C200 CDI - Limping

[starrzo]

Hi - I bought a 2004 C200 CDI auto (with newer style interior) around 3/4 weeks ago. Since then it has been an uphill battle

When I got it I soon discovered that it was very smokey, and it would go into limp mode almost every time it was driven for more than 10 minutes. I cleaned the EGR valve which was definitely sticking and gunked up, but the problems persisted.

I have taken it to a local independent, and so far he has done the following:

* Intake manifold removed, cleaned and butterfly valves removed
* New fuel filter
* New glow plugs
* Replaced (fuel?) quantity valve from another car

Apparently the car has been put through numerous STAR diagnostic tests and everything, including the injectors, look fine. Also the MAF is reading correctly I am told.

No codes are registered when the car goes into limp mode. I drove it last night and it doesn't smoke the way it used to, however it limped after around 15 minutes of driving (limited to 3000 rpm).

So the question is, what is next? Could a blocked DPF be causing this? I have attached a photo of what I believe to be the DPF, am I correct?

Thanks in advance.

 

[olly398]

WOuld be interesting to see what the STAR readout for DPF ash content is. Mine (C220 w203) went limpy last year and it was the air mass sensor. We replaced it, the DPF started regenerating again (couple of bottles of Forte to help it) and it was right as rain. YMMV.

 

[wongl]

If the MAF is causing the car to go into Limp mode, this means that the ecu is aware that the MAF is faulty. Once the ecu registers a faulty MAF, will it smoke?

Was there any particular reason your Indy replaced the glow plugs? Glow plugs are normally used to start a cold engine, so unlikely to cause smoking when the engine has been driving for over 10 mins.

I wonder if your oil level is too high and expanding even more when the engine has warmed up? Worth checking? I have heard of an out of calibration injector(s) dumping too much diesel fuel into the cylinder and leaking into the oil sump causing the oil level to rise significantly.