Turbo noise

[dennis]

My 240 Volvo wagon makes a noise that sounds like turbo whine, but is NA. Goes away when you let off the throttle. Pitch change with throttle change. Pretty strange. I though it was noise from the radio at first, but does not go away when the radio is off. It is a d24 engine which is the same as a VW 1.6 but with two extra cylinders.   

[Syncroincity]

Pitch changes with engine speed, or throttle position?

I'd check your belt covers first, make sure nothing's rubbing, or come loose.

[burn_your_money]

I'll take a guess at a restrictive exhaust coupled with a pin hole leak near the manifold

[dennis]

Pitch changes with engine speed, or throttle position?

I'd check your belt covers first, make sure nothing's rubbing, or come loose.

Throttle position. Mostly from part load to ful load. If I completely let off the throttle the noise stops.

[dennis]

I'll take a guess at a restrictive exhaust coupled with a pin hole leak near the manifold

Thats a thought. Actually planning a turbo engine later, so a bigger exhaust would not be in vain.