Gr2331mj

My radiator blew on 2003 Cherokee 4.0. Replaced rad, when I start it up I can see the coolant in the container on left begin to bubble, and the engine smokes a little in the top and out of the oil cap on top of engine. I'm going to replace head gasket. What are chance it's my transmission? Any suggestions?

BlackHart

Why are you thinking transmission? And does it bubble constantly?

Bustedback

Put a cooling system pressure tester on the radiator, don't pump it up. Now start the engine and watch the gauge. You shouldn't see a rise in pressure until the engine reaches operating temperature. It you see the pressure build quickly from a cold start you may have a blown head gasket. I don't know why you would think the transmission would be the problem. A little oil vapor from the oil fill cap is normal.

MNOE

I don't mean to thread jack here but, would a blown head gasket cause a misfire?

Bustedback

In most cases it will, but not all of the time.

munyanb

Does it overheat now? Is there water in the oil? does it look creamy? How bad did it overheat? With the cap off , can you see water circulation? Don't remove the cap when its hot, but only when it's cold. You haven't been very specific with the info. The bubbles could have just been air coming out of the system. And explain why the transmission is suspect?

munyanb

A misfire can be caused by anything that makes you misfire, lol. A cracked valve, head gasket, bad gas, clogged injector, bad rings, etc. A head gasket usually has some more tell tale symptoms like mixed fluids, or coolant system blowing out, or something usually points in that direction.