ML 270 Rough running

[sappers]

Hi, quick question from new owner. I have an ML270 2002 CDI and it runs great when cold. When warmed up it will run to 2000rpm then sounds like the timing is off (as if it was a petrol model) and huge clouds of black smoke. A bit gutless until it gets up a bit of speed, say 70mph and then it's off like a train. Any thoughts? Recently had fitted new inlet manifold and swirl flap motor, gearbox fluid, filter and contact plate and a new battery.

 

[sappers]

Forgot to mention, once it reaches 2000rpm when in P or N the revs suddenly jump to 3000rpm and over.

 

[91dm]

Any lights on or have you plugged it into STAR?

 

[sappers]

No, nothing at all. Had it plugged in a couple of weeks ago and flagged up all the above problems but no lights or anything this time. I have plugged a generic wifi adapt or in and used an iPhone app but still no codes stored or pending. Does anyone know when the turbo starts to spool up and boost; wondering if this was related to 2000rpm.

 

[91dm]

Should have boost at roughly 1600rpm and from 2000rpm really pulling well.

I had a similar issue, no power or boost when warm and lots of black smoke which was caused by a bad MAF.

 

[sappers]

Thanks for that. I will try and find the specifications for the MAF and go from there. The only thing I know for sure is that it's not a genuine part.

 

[91dm]

The MAF I removed wasn't a Mercedes part but I replaced it with one which has made the difference. Even with the bad MAF, mine still sounded the same. Maybe a video of the sound would help?

 

[sappers]

I will try and video it this weekend