So my jeep runs and drives great, after about 20 minutes or so its starts to idle rough and want to die.

There is no white smoke, no water in the oil, BUT there is a verrrryy slight sheen on top of the antifreeze in the radiator. Like when water turns rainbow colored when oil is introduced. but it is barely noticeable.

The main reason I am thinking headgasket is because if I go out in the morning when the jeep is completely cool I can start it and let it run for literally a minute or two, shut it off, open the Rad cap and water shoots out like its been pressurized.

Is that normal before then engine is even warmed up at all? The water is still ice cold but the rad seems like its pressurised by exhuast gas?

Thanks for any help, I am gonna do a carbon test on friday but was just wanting some input before so.

Matt

 

Do your test. Right now anything would just be speculation.