2003 PT Cruiser turbo. Has just 67k miles on it. Just began making a low pitched loud whistle sound on acceleration or load/uphill. Gets louder with greater acceleration/load, no decrease in power.

any part driven by the drive belt can do this

air leak.

pomerstearing pump

HOW MANY MILES ON CAR.

check the turbo outlet pipe ,from turbo to inlet manifold ,sounds like it has a leak

Sounds like a throwout bearing is dry.

does it quit after it warm up or while driving it?your belts might be loose

Turbos are fairly simple pieces of equipment and the failure almost always happens in the bearings. It sounds to me like one or both bearings are shot and aren't allowing the impeller to spin up properly. You'll need a rebuild or a new/reconditioned turbo.

My pt gets only 16 to 18 miles per gallon.check your air filter.

It's probably the turbo you're hearing. They spin very fast and make a noise like that. Ever hear an 18-wheeler go by you and accelerate and they make that high-pitched whistle? That's the turbo spooling up. Now, if it sounds like a dentist's drill, that's usually a sign that the turbo is failing, but I'd bet that since your car is under four years old, as long as you've kept up on the maintenance, it's the normal turbo spool.