I've got a 1994 Impreza with 101,000 miles. It has developed an oil leak that only occurs under hard acceleration, such as when entering a highway. Th leak is hard to pinpoint, but it is coming from the back of the engine and it's landing on an exhaust part, producing smoke. Again, the problem only happens under hard acceleration. Anyone know what's going on?

Could be camshaft seals, one on either side of the front of the engine. Check underneath the cambelt housing. Crank seal in the middle could also be the culprit. Or maybe all three!

 

 

You might lucky, and it's only your rocker cover gaskets. These are easier to replace. Both sides of the engine. If these are leaking, the bottom of the engine cylinder heads will be covered in oil.

Replace the PCV valve too, as this will help relieve the pressure that forces oil out through these gaskets.