2001 Chrysler PT Cruiser whirring

My cruiser makes a whirring noise coming from the engine/drivetrain

Does it do it when revving in park?
Have a helper rev the engine. Listen closely around the serpentine belt for the noise.
Remove the belt (engine off!) and turn the pulleys by hand to see if they work smoothly.

Under what operating conditions?

A few years ago my car started making a whirring sound. Someone described it as the sound of an alien spaceship landing. It was coming from the alternator.

I ordered a new one over the internet, planning to change it that weekend. Then, on Friday, on my way to work, the whirring one left this life. I drove straight to a shop to have it replaced, knowing I’d never make it home again (30 miles) on just the battery, and when I got home my new one was on my doorstep.

Thank you for the reply. I get the sound, which from behind the wheel sounds like it’s coming from the left front of the engine bay, while in gear and under throttle or coasting. I don’t hear it at idle or when revving in neutral. The car has 91,000 k on it. I recently replaced the timing belt, water pump, motor mounts and axels/boots. You’re right about it sounding like an alien space craft.

You might be able to zero in on its source with a mechanic’s stethoscope, available anywhere including (I think) Walmart. They’re dirt cheap.

A loose or torn CV boot can produce a kind of hollow resonating sound, but not at idle or revving in neutral. Having just put a new OEM Honda CV boot on my Civic, I found it takes a lot of force with the right tool to tighten the boot clamps adequately; and the clamps that came with an aftermarket boot I tried are not nearly as sturdy.

The_same_mountainbike: Thank you for that tip. I try Walmart first.

I believe that your car has a noisy wheel bearing. Take a mechanic with you for a drive, should be easy to identify the noise.

Thanks for the reply. I have a trusted mechanic who’s hourly rate is $85 vs the market rate of $130 around here. Off I go first thing tomorrow to see him.