Buzzing noise that stops when warmed up

[KMG]

Hi, I have a '64 156 THP GT with 36000 miles on the clock, and for the past year I've had an intermittent 'buzzing' noise like a wasp in a tin can when driving from cold at around 3000 revs. This noise stops when I accelerate and when I slow down, and it disappears by itself when the car warms up after a couple of miles. I've just had the car in for replacement seals in the turbo oil return pipe, and the mechanic says he experienced said noise. He thinks it could be the Cam Chain Tensioner, or the VVT unit. He's put a special additive in the oil that is specially to treat this symptom and says hopefully it will cure it, as it could just be a bit 'sticky'. He's advised me to ask on this forum if anyone has experienced anything similar. He also says if it continues he will change the offending item to be on the safe side. If anyone has any thoughts on this I'd be grateful for their advice.

Thanks,

Kevin

 

[Kenneth]

I had a noise like that but it was only when the engine hit about 3000rpm. It drove me nuts for a while until I realised a bit of that bendy heat shielding stuff hadn’t been moulded back round some wires and pipes on the left hand side of the turbo after I’d been mucking around with something down there…. Turned out it was THAT. And it did really only do it until the engine got hot.