Rough idle

4.0 V-6 165,000 miles

I have a rough idle after engine is heated......

Coil pack, plug wires and plugs are relatively new. I use 93 octane gas. Any ideas?

Thanks

4.0 V-6 165,000 miles

first off, you only need 87 octane. second those things are fairly notorious forthe upper plenum seals leaking. the first one i did took about a half hour so its pretty easy. you dont have to disconnect everythign just what you need to lift the intake up enough to change the o-rings and clean the surfaces. if i remember right on the driver side up front behind the bracketry there was a metal bracket that i cut in half and tacked back together.

Thanks man....

So are you saying the intake manifold gasket is leaking? Or does it have o-rings? What is the plenum? I also have a small coolant leak from the back of the engine also........