Whistle

[nuggety]

Hi ive got an annoying whistle everytime i pull away and slow down i changed the manifold gasket last time it happened but its come back slightly different tune this time and ive checked the manifold bolts any suggestions

[4bye4]

Not much info mate - but sounds like you are on the track, probably air leak somewhere, cracked manifold, manifold gasket or may be warped manifold. Without details of the motor its a hard one to call. Welcome to the forum by the way.

[JackCollo]

Does it the pitch change at all with engine rpm? And do you have a boost gauge installed?

[JME_GU]

Any cracks or deterioration in the air pipe from the airbox, or to/from intercooler?

[JackCollo]

Check all your intercooler rubber pipes as I found on my own patrol the heat and pressure had cause a tiny split in one of the hoses
All I can suggest is check all your boost lines and intake lines and pipes make sure everything is tight and not splitting

[Bush Ranger]

Check the little alloy manifold that connects the egr stepper motor (I think it`s called that) that recirculates the exhaust gas back in to the motor, it may be warped at either end flanges. I had that problem after replacing the the stepper motor. I only noticed a whistle every time I took off at certain rpm and differing times in other gears when adding more power.