I'll just cut to it. It has 198,000 miles on it. This will be my first big project with the Jeep. Have only done easy maintenance thus far (spark plugs, tires, brakes, shocks) the biggest project completed thus far was the radiator. I was then dealing with an annoying oil light that would come on at idle. I changed the pressure sensor, thinking that would be an easy fix, but the the light persisted. Then I started to get an intermittent high rev at idle. Which then turned into what is now a real performance problem. Everyone I've talked to suggests replacing the head gasket. Seems to be a lot of enthusiasts/ knowledgeable people on this site, so I figured I would see what yall thought.

 

A high idle can be a sign of a bad head gasket, but there's many other things can cause it as well. TPS (throttle positioning sensor), IAC (idle air control), vacuum leak, stuck throttle body, among others. So, i wouldn't start buying parts just yet.

 

if nothing else, at least do a compression test before you pull the head off.