Volvo noise problem

There is a knocking noise coming from the right front of the my vehicle during acceleration. The noise stops when I brake. What could be the problem?

Model Year, Please? Approximately How Many Miles On This Volvo S80?

Model year is 2003. Approximately 90,000 miles on the car.

Do You Have A Bosch Engine Management System (As Opposed To Denso)?

I found a Volvo TSB (Technical Service Bulletin) that lists an engine knocking or rattling noise as one of several symptoms to a faulty V V T or C V V T ( variable valve timing) solenoid in Bosch engine management systems. The plunger in the solenoid can stick. I’m not sure if this would make the noise sound like it’s coming from the right front or not.

Additionally, they say that this problem can cause poor performance (of course) or illuminate your “check engine” (MIL) light and set codes.

The “fix” is to have the V V T solenoid checked and if necessary cleaned, following Volvo’s procedures.

I’d run this by a competent, experienced Volvo mechanic who can access the bulletin and see if this is a real possibility.

Does Your car’s performance suffer or has the engine light come on?


Check the upper engine mount. It is on top of the engine drectly in front of the steering wheel and attaches to the firewall. They frequently fail.