sixpack
Senior Member
- Joined
- Mar 17, 2003
- Messages
- 187
- Reaction score
- 2
- Location
- Renfrew Scotland
- Your Mercedes
- 2012 w212 220
Hi forum
My 2002 c270cdi makes a kind of thump thump thump sound, at crankshaft speed. Its worst when cold and almost disappears after about 3 miles warm up. When hot, it does it under acceleration. Excuse the description but Ive never heard this sound before. Idle is OK, power is OK, it goes like stink, and economy seems OK. I thought possibly an injector because the noise is not present if you take your foot off the gas. Ive tried listening to all 5 injectors, they all sound the same but Im probably just hearing the sound of the solenoid operating. No warning lights show but I havnt had it to a dealer to look at codes. Anyone had this before ?. I was thinking of unplugging the power to each inj. in turn to see if I could isolate it further but would this be safe, or cause a fault code. Any comments welcome.
Peter
My 2002 c270cdi makes a kind of thump thump thump sound, at crankshaft speed. Its worst when cold and almost disappears after about 3 miles warm up. When hot, it does it under acceleration. Excuse the description but Ive never heard this sound before. Idle is OK, power is OK, it goes like stink, and economy seems OK. I thought possibly an injector because the noise is not present if you take your foot off the gas. Ive tried listening to all 5 injectors, they all sound the same but Im probably just hearing the sound of the solenoid operating. No warning lights show but I havnt had it to a dealer to look at codes. Anyone had this before ?. I was thinking of unplugging the power to each inj. in turn to see if I could isolate it further but would this be safe, or cause a fault code. Any comments welcome.
Peter