Armando S Nortez

This problem started not to long after my wife was using the car and the coolant light came on she let some sears people put dex cool in the engine. this car had never had dex cool used in it just standard coolant.
suddenly after the car has no heat ive check the heater core water flows easily in either direct i removed the vacuum controlled heater valve top piece with a pipe cutting tool so just the stud was left and placed the heater hose directly on it. I've changed the thermostat and refilled the system to capacity.
The outlet that is the hose that sends coolant to the heater core in take does not have any coolant coming out no more then a small trickle then nothing.I know this because i was able to remove the hose while running the engine hot and no big steam cloud what could be causing this.

307 Y ENGINE WITH COMP CONTROLLED Q JET ROCHESTER

M-14

Is it really low on coolant? It might have air in the system.
Is the water pump really old? It might have an eroded impeller. This is kind of rare & the pump would have to have a stamped impeller (olds had cast one from the factory) for this to happen.

Lady72nRob71

Clogged heater core?
Disconnect and try to force water through it with a garden hose. Couple the hose to the core with your hands to avoid damaging the core.
Try forcing water from both sides and see what happens.

If you take the hoses off and there is no coolant, then the system was not full enough, or burped enough when it was last filled.

Armando S Nortez

ok finally going to get in to it folks sorry for long reply it was summer so it went to the back burner any idea how to take that valve off i suspect a clog standard tools wont fit in that spot

tru-blue 442

Do THIS first. ^^^

rocketraider

DexCool and regular green coolant do not mix well and when mixed and heated will create a sludge. My guess is the heater water valve is clogged or possibly heater core itself.

I'd have taken it right straight back to Sears and invited them to do a COMPLETE coolant flush on that car at their expense. That would have included a new thermostat and heater water valve. There is no excuse for them having put that DexCool in a car that had green coolant. None.

If you haven't, you might as well count on having the radiator cleaned too because I can about promise that gunk is laying out in the bottom of it.

A crowsfoot type wrench will make removing the heater valve stub easier.

J-(Chicago)

Heater control valve inlet pipe is clogged now. That would be my first guess. The opening at the bottom is pretty narrow.

Unfortunately, the easiest way to take it out with all of the 307 emission items in the way, is to hack saw the big head off of it, and remove the stump with the appropriate socket and ratchet. I see you already cut the head off of it, but the restriction is in the pipe that you left in the intake.

It's a possible can of worms, for sure, since you have the aluminum A5 intake manifold. You can put a larger diameter pipe nipple in it's place, and re-attach the heater core until you get the system properly flushed. Good luck.

I believe the restriction was put there at the bottom of the heater control valve to prevent excess pressure into the heater core, but I have never had a problem running coolant through at wide open volume. I keep the coolant temps down around 180, so I'm not really worried about a 260 degree coolant/heater core explosion behind my dashboard and inside my AC box.

tru-blue 442

This was what was in my 98 Chev shortbed when I got it,
so I can attest to it. The heater core was so sludged it
was plugged.

I took the yard hose to it, blasted back and forth, upper, lower.
It cleaned out well. Note, that was summer with a black 75'
waterhose at about 150* and a lot of pressure. Small bursts
worked well. Never leaked and the heater began to work again.
Went back with the green. I HATE dexcool btw.

Good luck. I'm with Eric, the shop screwed up. They should
be held responsible.

Armando S Nortez

hopefully get to it this weekend ive gone over the core twice it wasnt even slightly restricted i have to get that stupid heater valve off of the intake manifold does any one know the bolt head size i though it was halfr inch last i looked at it im think of getting a big impact socket

J-(Chicago)

I think it's 1" , but don't remember off the top of my head.

olds 307 and 403

Dexcool and regular green do not mix. It looks like clay, not pretty. Soon that won't be an issue with the universal stuff being sold everywhere.

Armando S Nortez

well i didn't actually take it off but i was able to shove slender torx driver down in there and dislodge what ever sludge was blocking it now all i have to do is follow with a flush but heat is restored i appreciate every ones help