head blown ?

I need some other symptoms of blown head gasket or head issues. I don't see white smoke from exhaust, I don't see any foam on the dipstick, but I do see some underneath the oil filler cap. This truck has blown head gaskets in the past. The radiator was clogged, and the thermo was stuck open. So I replaced those and it was fine for about 500 miles. It suddenly got hot when I got to work, so I quickly shut it off. I looked in radiator & overflow, it was low. So I thought some of the bubbles in the system had come out, and level dropped. I drove it home, temp stayed good. One symptom it just started doing was rough idle, but smoothes out when you get going. So any thoughts ??????

Doe's the coolant system smell contaminated with fuel, or oil smell?
You might consider http:www.steelseal.com

The most common symptoms of a bad HG are white exhaust from burning coolant, and/or coolant and oil mixing.

You can do tests like pressure leakdown test on the cooling system and cylinders to check for/locate a problem.

I was just going to post up a question regarding HG. I have a first gen 89 4Runner 3.0 V6 and been noticing lately that my exhaust is super rich and smelly, white or grey in color. I had my timing belt done about 7000kms ago. I am not going through any coolant, and I have not found any oil in my coolant resevoir. Temperature guage is always steady never moving up and down while driving and at an idle it holds steady. It seems sometimes the smell is worse than other times, make any sence? Also at an idle I notice that the tail pipe will blow rings of smoke is that odd? I never noticed before. But it is getting pretty bad and feeling guilty about the smoke kicking out my tail pipe everywhere.

With the timing belt do I have to have it adjusted after it's been installed originally? Could I be running rich and pushing non combusted fuel out the tail pipe? Everything around the engine itself is tight and clean and not leaking anywhere. What is my next check? Should I get a compression test to see if I have a bad piston?

From what you describe it sounds like you may be running rich. You might trying seeing if the ECM has logged any error codes that might help.

I took my 4Runner in for a compression test and I had 0psi in my number 6 cylinder. Guess I broke a ring. My time with this vehicle has ended, sadly a chapter has closed. So long Frank N Stein my friend. I have sold you to another owner and hope you are treated with the respect you deserve.

I just wanted to let you guys know, it was the head gaskets !!! I had heads surfaced & tested, replaced head gaskets, got all new hoses and the good news is its running great. I got that freakin' air bubble up around the heater core that interfears with the overdrive and stuff...but I parked it on a huge incline and it worked its way out. So thanks all you guys for the advice ... :cool: