KroniK

Long time lurker, but I now have a reason to make an account and post.

So recently I bought a 94 Pickup with a 3-VZe Engine in it. When I bought it, it had a bad O2 sensor so It wasn't running well. I replaced that and noticed it needed a little more radiator fluid. Filled that up and then when I started it white smoke came pouring out of the exhaust. Long story short it had a blown head gasket.

Tore the whole thing down and rebuilt it. It seems to run well, no white exhaust etc but it overheats very quickly. In fact, if I let it run with the radiator cap off, after about 10-15mins the coolant starts shooting out of the cap like a geyser about every 2-3 seconds. It will erupt and then settle down, erupt and then settle down, all in about 2-3 second cycles. It starts off very small but if you let it run very long the water will start spraying well above the hood.

I have tried bleeding the system several times. I get great heat out of the heater, and when I start it up and put my hand over the radiator cap, I don't feel any pressure from what would be a bad head gasket or cracked head.

I have tried replacing the T-stat and inserting it correctly with the small hole at 12 O'clock and It still seems to overheat.

I tried driving it about 5 - 10 miles without a T-stat and didn't have any issues with it overheating and I got it to the point where I was getting heat out of the heater. I didnt push it very hard though.

last night I pulled the T-stat back out after overheating it again (within about 20 mins) and there was no liquid behind the T-stat. I cracked all the nuts that hold the hose on to the T-Stat and let it drain, opened it the rest of the way and saw that the T-Stat was still well sealed. I popped the T-Stat out with a screw driver, expecting hot coolant to pour out behind it but nothing ever came out. The T-Stat was closed when I pulled it out.

Anyway Im confused as to what could be causing this. I did look over the heads and block carefully when I had them out. I resurfaced the heads and inspected them myself (I have a CNC mill) and didn't find any cracks. The engine was supposed to have had a complete rebuild at one of our dealers in town only 20K miles ago!! because of this I did not pull out the valves and inspect the valve seals for any cracks (plus I don't have a valve spring compression tool) so I guess that is a possibility. And It could be that one of the gaskets I got was bad or something, but I would guess that I would feel the pressure when I covered the radiator cap.

Any Ideas are welcome... Im at my wits end.

Punchy

Good chance the heads are cracked, And most likely the headgasket is blown again on #6, Any kind of over heat blows it soon.

When you get it all done again, Make sure you have the radiator shroud and a good clutch on the fan.

Slowey23

sounds to me like your water sysem could be blocked, try removing the thermostat, seal a hose for air or water in that outlet and pump which ever in and see if it comes out

Co_94_PU

iTrader: (-1)

You may have made a mistake when you put the gaskets in, it's a common error. Poke around a bit and you'll find some threads and photos.

Rent the coolant test light and chemicals from the local parts store. This will rule out exhaust gases and oil in the cooling system.