There are two things that could be happening;
either the valve cover gasket is bad and the spark plug is not sealing and oil is leaking into the spark plug well and into the cylinder.
If it is the head gasket, there could be other issues as well. The oil could be getting in from a leaking valve stem seal or there may be a crack in the block.
Normally to change a 4 cylinder head gasket is around 6-8 hours of labor. So it depends on how much your repair shop charges per labor hour.
If the valve stems seals need to be re-done you need the head rebiult and that can run $1000-$1500. You should also consider just rebuilding the whole motor if the head needs to be rebuilt or at least re-ring it.
Friday, February 24th, 2012 AT 1:29 PM