Uneven tightening of the valve cover can result in leakages. A bad gasket could also be the cause. If the leak is from around the arches of the cam holders, that could be because no sealant was applied or not applied evenly.
If the IAC is not operating, it would cause idling problems. Surging are usually due to idling speed excessively high.
Friday, May 24th, 2013 AT 7:54 AM