Strange noise ?

[daze]

Hi everyone, i have a 2001 c270 cdi that is making a strange noise
It only does it when driving and there is no loss of power and the auto box changes gear as it should ????
Any suggestions welcome as i'm now thinking i should have bought a beemer

 

[Sp!ke]

I think you need to fescribe the issue in much more detail before anyone could attemt to offer an opinion.

 

[daze]

Oops sorry I thought the video would have explained it ? Anyway it sounds like something is catching and sounds like its coming from behind the dash ?? All the injectors are clean and the drive belt runs smooth and that is where me having a clue runs out

 

[Sp!ke]

Sorry, I didnt realise that was a video. That doesnt sound healthy at all. Is it running on all cylinders, Is there any black smoke?

 

[daze]

Runs fine, no black smoke starts fine ! This noise only happens when it's moving when it's parked it revs fine with no knocks or rattles ! It's got me stumped

 

[davidsw]

Does the sound change with engine speed or road speed. Cruise at say 40mph then change down a gear keeping the road speed about the same but increasing engine revs.

 

[daze]

I would say more with the speed but I'm going out in a bit so I will try changing gear and let you know

 

[daze]

Then again when I back off the throttle it virtually stops !

 

[davidsw]

Could it be prop shaft under load ?

 

[daze]

Mmmmm never thought of that ! How would I check that ??

 

[davidsw]

On a ramp check for play I guess. Have you a local mechanic who could have a quick look and listen . I would think he could track noise down .It is very difficult with noises especially when you can't hear them live under different driving conditions

 

[daze]

Well I have just been for a drive and at 45mph I dropped it down to 4th then 3rd and no change ! You would swear blind it was the cam but its not lol

 

[daze]

Well its sorted ! after reading every post relating to noises on mercs i went simple and checked the parking brake cable above the prop shaft and hey presto broken clip ! a dril, tie wrap and 10 mins later all done lovely and quiet

 

[Terry_]

Well done chap