Hello,

I recently had a valve job performed to my S40 Volvo and i noticed loss of power. When i accelerate my car noticeably has loss of power and takes longer to get up to speed. At idle it sounds great.

What could be the problem?

 

Wow, this could be anything. Assuming the valve job was performed properly it then boils down to how the car was put back together.

Is there anything noticeably different like smoke from the tail pipe, or loss of oil or coolant?

Have you read the codes to see if you have any stored? Is the check engine light on?

Give us a little more background to help you narrow it down.

 

Check that all vacuum hoses are connected properly and in their proper place. Often it would trigger an error code but not always.
Stan