I am working on a 2011 s40 that had timing belt failure and I replace head and seals. Car running well but I have an oil leak on the top end of engine and on the intake manifold side of the engine. Suspect poor seal of the camshaft cover but also concerned for pvc system (oil scavenger ). Any Ideas. Oil is all over the top of engine and fills spark plug wells of 1 and 2 sparkplugs.

 

If you used the Volvo-prescribed anaerobic sealer on the top part of the head and installed the O-ring seals around the spark plugs, the head seal should never leak.

Since you mention that the oil is on top of the engine and filling the spark plug wells, check for a good seal at the oil cap. The rubber seal in the oil cap will deteriorate and leak like there's no tomorrow. I keep them in stock and you can buy them online cheap.

Send a pic if you have one.