Any ideas ! Strange thumping noise

[shamedpot]

Recently noticed this strange thumping noise on cold starts goes away once warm doesn't sound DMF issue no warning lights van drives great ? Doesn't seem linked to engine rev speed or clutch movement and not a constant noise just a random thumping

?

 

[Chrishall888]

Is the belt jumping about much?
Maybe tensioner for the aux belt?
If it’s on the o/s I’d take the belt off and try without

 

[shamedpot]

Thanks for the reply I thought it maybe the belt and half it changed last week with a new tensioner but still same ?

 

[Chrishall888]

Did you run the engine with it off?

 

[shamedpot]

No a garage did it and oddly enough it's only when first cold in the morning any other time to there's no noise ,,!

 

[Chrishall888]

That would be my first step. Not a difficult task to do on the drive.
It would help rule in/out the O/s pulleys, alternator etc.