I'm thinking of buying a 2005 Volvo V5 T5 (turbo) tomorrow. Nearly everything has checked out pretty well (I took it to a Mechanic today who looked it over).

I've noticed that when the engine warms up just a bit, and as I accelerate, I hear a faint, but distinct, whistling noise. It's not the screaming noise I've heard in other videos nor is it the screeching or whining noise. The whistle that I hear is a fairly low pitch and the pitch does not change regardless of the speed or the rate at which I'm accelerating. It only happens when accelerating and when I let off the accelerator it stops like air being let out of a balloon.

One possibility is that the PCV hose is cracked but I could not confirm it at the mechanic since we didn't look. I later found a video on YouTube that may point to a possible culprit but I simply do not know.

I thought I found a forum that would answer this question but when I clicked on a link it directed me to a page that is no longer there.

Any help would be greatly appreciated.

 

there's a few things that come to mind which can produce a whine or whistle - the turbo, brake booster, vacuum pump, PCV and other hoses, even the power steering container. If you can hear the whistle while revving the engine in neutral, you may be able to use a hose as a listening tube to see if you can isolate the area - ie front of the block would suggest PCV or power steering, back the turbo/exhaust, up high the vacuum pump or brake booster...

 

That's helpful. I will have to do some diagnosis on that when I get the chance. Some newer issues have come up that I need to diagnose.