kmchby76

ok guys, i got one for you. my brother in law has a 95 runner with a 3.0 v6. after about 3-5 miles of driving, his runner overheats. when we pop the hood,, the coolant is boiling in the radiator and the hoses and venting through the resevoir tank. we changed the themostat and added new water/antifreeze mix, still doing the same thing. anyone else experience this, and what do you all think the problem may be. there is about 110k on the motor.

ChickenLover

That's the 'danger zone' for the infamous blown HG. Any mysterious loss of coolant? Misfire? Milkshake under the oil cap? White smoke out the exhuast? Let's hope not.

Does the fan appear to be working properly? Can you hear the clutch engage when things start to heat up? Could also be as simple as a clogged radiator or weak water pump. Lots of possibilities.

TNRabbit

I second ChickenLover; sounds like a blown head gasket or water pump going bad. I had a wate pump do this (but I could drive about 50 miles before it overheated) and it actually took about 3 months for it to finally give up the ghost.

ovrrdrive

3-5 miles is almost a guaranteed HG if you're sure the thermostat isn't in backwards. .

Assuming the water pump actually circulates water, do a compression test.

wittekl

i have had this problem to, when i purchased my 95' i did general maint. to it and when removing the thermostat it had two wholes drilled into it. So at this point im just thinking what kind of redneck intervention it this, so after installing a new stant thermostat it ran hot in like 5 min would idle fine. i took everything back out and drilled two small wholes in my new thermostat. then last week i decide to go and buy a new therostat from toyota and a new radiator and put all new in to try and solve my problem. i out the new thermostat in fill the radiator half way and start it and pour it in slowly well sure enough it runs warm again. so i call my mechanic and he says that the 3.0 will create a huge air lock in the motor which is a flaw from toyota. so he says to drill two more wholes in thermostat and fill the radiator half way and to add the rest of the antifreeze very slowly. so i do prolly took me 20 minutes to fill while it was running, make sure you put the cap on before it reached operating temps. but she runs good as new. hope this helps !

kmcc78240

I did not have this problem, the thermastat part, mine was a blown headgasket.. Also a compression test might not always see a blown headgasket, get the coolant tested for exhaust gases.

scooby77

I have the same "boiling" coming from my 95' V6, but the temp has never risen above normal and the boiling is very random. It has been happening only once or twice a week if that, on days warmer than 90, and seems to begin as soon as I turn off the engine. Stopping when the engine is turned back on. Could it still be the head gasket or more likely an air pocket. Also, I had the coolant flushed last fall and never had a problem until this spring. Could it be as simple a bad cap or radiator for that matter?

regularguy412

If your cap is bad, it won't hold pressure on the system. Coolant under pressure can reach a higher temp before boiling over. That's the way it's supposed to work. Also remember, that an engine (coolant) is always hottest just AFTER you shut it off. It's not unusual for the engine temp to rise 20 degrees or more, right after you remove it's ability to cool itself. If the cap is bad, that little extra amount of heat after shutdown might cause it to boil.

Mike in Ar

rdharper

:pat: Of course!!

kmchby76

hey everyone, sorry i haven't been online, just moved and had no internet, but i'm back. thanks for all your feedback. we did find out the problem. first we changed the waterpump as it failed. after i posted i found out my brother in law poured 2 servings of bar leaks for the radiator. you guessed it, the radiator wat clogged. bought a new radiator and the runner is back on the road, i even think it runs better than my 96 runner. well thanks again for all you feedback. by the way, i know that the toyota dealer her in elk grove, ca does have a service recall to inspect the head gasket on the 2nd gens, might be worth checking out.

scooby77

So does anyone have an idea to what the symptoms previously stated could be telling me? Boiling from time to time, doesn't overheat, begins when shut off. Need to know, taking family into the mountains soon and don't need any hang-up or bang-ups.
Thanks in advance.
ps. was flushed last fall, REAL DIRTY, possible spuratic blockage...wouldn't think so because of even temp? Or could it be the infamous air pocket?

TNRabbit

What exactly is the boiling? Is it a sound coming from the radiator, or is it actually boiling over from the radiator cap or into the overflow??

scooby77

At least in my case it has been the sound from the radiator & into the res. It did overflow once out of the res., but I think I had a little too much in the overflow res.