Low Whistle

[Daveathome]

Hi all 2003 125/350 Jumbo

For the last two days when on 1st start up I have been getting a low whistle noise as the revs build up, but only until the engine reachs temp
if i lift my foot it stops but if i put my foot down its starts again.
As soon as the engine is at running temp its fine no loss of power, no smoke, no odd noise's.
It had a new Engine and turbo 16k ago

[BigNeil]

sounds like a belt which is loose then when warm it expands and the noise disappears, could be alternator belt. hope this helps

[Daveathome]

No I don't think its the belt as I changed it about 4 weeks ago

[Daveathome]

I have checked all the pipes to the turbo all seem ok no splits or holes ????