Strange Whistling sound

[Giovanni]

I drive a 122s which has recently been restored. Recently I have noticed that once the car is warmed up and driven normally a strange whistling noise is heard from the engine when driving, the strange thing is that this noise stops when I accelerate and is clearly heard when I take my foot off the accelerator, any Ideas???
:lightbulb:

[asneddon]

I've got the same problem on my 1800 since having a new exhaust fitted. Whistle at very light throttle, no whistle when under load. I've checked air filters and manifold for leaks and can't find any. I think it's to do with the exhaust. See my thread on how to waste £700.

[Giovanni]

I have taken the car to get tuned and the mechanic is having problems in getting the engine to behave itself, the CO2 and the HC keep varying and dont seem to stabalise. He thinks there is a leak at one of the rods but is not too sure as he has never came accross this before. Can anyone suggest any way his theory can be tested and more importantly fixed.