interesting noise...

[RollingThunder]

When I bought the BoneWagon it was described as having a whine from the cambelt end of the engine, and indeed it does. Not all the time, just intermittently. I assumed that it'd be the PAS pump, maybe the aircon pump, or one of the tensioners. I managed to do some listening when the noise occurred today - its loudest when I put my stethoscope on the... oil filter! Its a genuine Volvo one so I assume its got the non return valve in it - has anyone come across this before? Or is it more likely to be the oil pump making a racket - I've never heard a noisy oil pump before so can't say either way.

[Harvey]

It could be the oil pump making the noise if the oil pick pipe / filter / sump " O " rings letting air into the oil pump.
Does to oil light flicker when the engine is very hot and at tickover ?.

[RollingThunder]

No, no warning light Harvey. I'm going to try changing the filter to see if thats got a sticky valve - I can make the noise stop by blipping the throttle. After that it'll return to idle without the noise which is what makes me think its something like an oil valve rather than a bearing of some sort. Hopefully