Sick sprinter PLEASE HELP!

[Murphy75]

Hello guys, I have a Mercedes sprinter 311 2009, A couple of weeks ago water pump failed and the van came to a complete stop, took it to a mechanic (not Mercedes specialist) he replaced water pump and van I driving fine, since new water pump we've had constant tapping which increases and decreases with acceleration, took it back to garage and he has inspected whole top end and can't find anything wrong with it. He has suggested taking it to Mercedes to see if it's a common fault but can't afford this at the moment, van is driving ok but worried this tapping will cause something worse. Has anyone experienced this before? Would be great full for any help.
Many thanks.

 

[wu56Shoozz]

When you say driving Ok, Is it pulling like it was before, performing as it was or does it feel down on power?? It sounds - and I may be wrong here that its timing is out slightly hence the tapping made...

 

[Murphy75]

Thanks for replying Shooz, yes still pulling as before, just the concerning tap.

 

[wu56Shoozz]

put a video up if you can for us to hear - get a long handled screwdriver and put it to your ear, point on the engine whilst running and have a listen, see if you can guide us more accurately to "where" the noise is coming from..

P.S Yer welcome

 

[wu56Shoozz]

I'm presuming that this is a 4 pot OM646 engine ??

 

[toolman1954]

I would have thought any decent mechanic, could easily diagnose where a noise is coming from? Using either the tried and tested screwdriver method, as wu ^^^ above suggests, or if you are posh, you might have a stethascope for a listen. If that doesnt work, then its easy to drop the drive belt off, and see if the noise is still there. That will rule out power steering pump, Water Pump, and the Alternator and also the Idler pulley. On my 312, which is a different engine, there is a spring tensioner that can go t*ts up and cause an awful noise.

Steve.