A bad valve cover gasket does allow oil to seep to the spark plugs. Its a relatively cheap replacement. On the other hand a head gasket replacement is major and expensive. When was the last time you changed your valve cover gasket if you have? how many miles are on your car?
White "smoke" (coolant vapor/steam) and gas escaping into the coolant = head gasket blown, 100% guaranteed. No other explanation. You likely have other issues as well.
You fail to provide basic info such as the YEAR, MAKE, MODEL, or ENGINE, but replacing a head gasket isn't cheap or easy - although some are much more difficult (i.e., any V-configuration). Start saving your pennies.
And what on earth is a spark plug that "pops up"??? What could you even mean by that?
Depends on what car you have. Some have separate spark plug oil seal or the seal is included on the valve cover gasket. You just have to remove the valve cover and check. It is a very easy job.
One of my spark plugs is popping up and saturated with oil and im assuming its valve cover gasket. Would a valve cover gasket cause white smoke coming from engine and coolant overflow tank boiling too? Im thinking it would be head gasket but I dont see oil or coolant mixing.
