I have a 2007 HHR with a small oil leak occurring at the left rear of the engine. (Passenger side near the fire wall) The oil is getting on the exhaust manifold and vaporizing. Any idea what might be the source of the leak? Is this an expensive repair?

 

Valve cover? And passenger side is the right. In the USA, anyhow.

 

Could be the front cover seal at the harmonic balancer, it could be the seal at the timing chain tensioner, also.

Can you get your phone camera in there and take a photo?

 

why not find the leak visually?
of course, you need a lift or a viewing hole, but I think it's faster and more reliable than just making assumptions

 

This Ecotec isn’t in an HHR but the photo demonstrates the oil being slung and blown back along the engine.