strange engine noise?

[CONDYBOY]

Hi all I'm getting a strange rumbling noise every now and again from the engine, most noticeable at tickover, if I rev the engine it goes away, then it comes back at intermittant intervals not regular. any ideas.
p.s. it's a v40 1.9dci.
Could it be the vacuum system or turbo?

[volvokid]

I get a slight rumbling noise SOMETIMES when I take my foot of the accelerator and let the car slow down in first gear at low revs but I think it’s the exhaust.

[nobananas]

Could be a alternator bearing or belt tensioner bearing starting to get noisy. You could slip off the drive belt and then run the engine, if the noise goes away then you know it's something driven off the serpetine belt. Or could be gearbox or clutch release bearing problem.

[CONDYBOY]

cheers lads I'll take a look as soon as I get the chance.