95Cherokee

Started to overheat, barely got it home, opened the hood and coolant had been shot out all over the inside of the hood.

Too dark to see anything right now, was it just a rad hose that cracked?

1976Mustang

Original radiator? I wouldn't be surprised if the rad's side tanks cracked open. That happened to me, but it wasn't as energetic.

95Cherokee

Just replaced EVERYTHING in the cooling system about 3 years ago, might be the thermostat or water pump or fan clutch, I'll see tomorrow.
I just put a 13 psi rad cap on it today, I know I should have 16 but 13 wouldn't cause a catastrophic failure.

1976Mustang

3 PSI is a lot actually, that might have been it.

carbuff

I just had the same thing happen to me. I look in my rear view mirror and theres smoke coming out the back. Pull it over and open the hood and there was coolant all over the pass side and hood. One of my heater core hoses was spliced with a dorman plastic union a few months ago. It melted and broke in half. I was shocked. luckily I had my tools with me and was able to rig it together to get home. I replaced it with a metal part and all is good now. Only lost a bit of coolant. It was definitely a scary sight, all that smoke coming out the rear.

95Cherokee

So the coolant decided to blow a quarter sized hole in the heater control valve, can't believe these things are made of plastic! It's so brittle it crumbles apart if I touch it.



Advance auto wanted $26 for one "made in China", 4 reviews, all bad, leaking within a week.

Paid double for one at the dealership, $52......but one year warranty and "Made In The USA" on the label.

EZEARL

Any particular reason you didn't just eliminate it?

95Cherokee

I want to! Will the heater controls still work, if so, why is there a heater control valve at all?

Pelican

Take it back and simply eliminate the silly thing. Another thread going right now with a picture.

EZEARL

Have to ask the engineers. They eliminated it in '97. I took mine out last yr when it cracked. Heater and a/c work fine.

95Cherokee

What are the negatives to this?

Pelican

Hot coolant just flows through continually. Heat is only dissipated when controls are set to a Heat function. HCV was eliminated entirely on later models.

EZEARL

Yep. Hot and cold are controlled by a blend door. Look under the passenger side of the dash and you'll see the cable to it. Make sure it's adjusted. If you do eliminate the HCV don't forget to plug the vacuum line to it. I haven't had any negatives to post so far.

95Cherokee

So I just replaced the heater control valve and added coolant, still overheating, the thermostat works I think, temp dropped down a couple degrees when it hit operating temp.

I turn on the heater and only cool air comes out, what does that mean?

There is no coolant leaking anywhere, efan comes on when A/C is on but doesn't bring temp down much.

southerutah

For the price of a thermostat I'd change it to eliminate possibility. Are the heater valve hoses attached to the right place. If hoses wrong wont let water thru heater core. May have a air lock . Did you run the motor when filling. As it warms up and the thermostat open level wil go down and need more antifreeze.