1990 Volvo 240 wagon sounds like a cat and may need an exorcism

It sounds like a huge, happy cat in a tunnel when turning right and accelerating at the same time. It’s an echoing whirring/purring sort of sound. Any ideas about what it could be?

It also clunks in the rear with slight vibration. Could this be caused by an issue with the rear suspension or the engine mounts or something else?

Also, the locks seem to be possessed. When I try to unlock all the doors by pulling up on the driver’s lock, the rest of the doors either unlock perfectly or lock harder, i.e.,all the passenger locks slam down and cannot be retracted. Sometimes the locks will either lock and unlock or lock and lock harder on their own while I’m driving. What is going on?

Please help!

The noise is most likely rear suspension bushings. In particular, the rear lower control arm bushings are suspect. This is a common maintenance item on 240 Volvos. Replacing them requires a special tool, which you can buy or you can make if you have a well-equipped garage.

The door locks I don’t know about. Our family has had several 240s and none of them ever had a problem with the locks.