C2- no heat

[John Pickens]

Was interested in a dialogue on a systemtic approach to discovering why
my newly acquired C2 will not produce heat. Would the sequence be fuse-
electrical-water valve-heater core? Thanks.

[Duke W.]

Re: C2- no heat

Check all the heater hoses to see if someone has installed a shutoff valve. Heater core water originates at the outlet on the inlet manifold with a 5/8" hose to the core inlet nipple. The 3/4" outlet hose routes to the tee for the expanison tank and then to the water pump nipple.

Owners often remove/plug heater hoses because of core leaks.

You should also verify operation of the air and heat doors in the heater housing and the three speed fan.

If you intend to do work on your car you should procure the correct AIM and service manuals for your year car.

Duke

[Jack H.]

Add-on

While this isn't very common, I HAVE seen it done.... To save $$$ or run to auto parts store, vac or water lines are plugged by prior owner shoving an appropriately sized ball bearing into the hose! This can be real FUN finding/correcting....

[john pickens]

Re: Add-on

Duke, I should also note that the air door pull is not functioning, seems the
knob is bent behind the panel.I do now have the manuals, and it doesn't seem that a closed air door would affect the heat production from what I deduce from the schematics. Would you agree?

[Bob R.]

Re: Add-on

C-2 Corvettes produce plenty of heat even with the fan off. If your not getting heat I would guess your not getting hot water flow from your engine. Check the hoses from the intake and water pump to the heater box. You might have blockage in the hoses or in the heater box. Or as mentioned earlier the old heater box may have leaked and someone disconnected it.

[Donald L.]

Re: C2- no heat

John
One simple check is do you have vaccum to the water valve?No vaccum no water to the
core.Also there is a brass vaccum switch under the dash on the box if you have
A/C.Check that too. Had a 66 with no heat and that was the cause.

[Jim T.]

Re: C2- no heat

Bought a 63 SS in San Diego back in 1968 and the heater would not blow hot air. Removed the heater hoses and flushed the heater core. It was packed with red rusty looking mud. Heater worked great after flushing it and the rest of the coolant system.

[Duke W.]

Re: Add-on

Agree. If it's a non C-60 car hot coolant flows through the core all the time. The left hand heater knob has an "off" "heater" and "defroster position, but regardless of where it's set, the heater housing should be warm all the time.

Jack's tip is a good one to check, You can probably feel along the hoses to see if they are plugged. You should be able to see the two heater cables operating if you remove the glove box.

My guess is that there's a good chance the core leaks, which is why it was somehow pluged, but if you get water flowing through it again, be careful that the coolant doesn't leak on the carpet and be prepared to pull the heater housing out for a core rebuild.

Duke

[john pickens]

Re: C2- no heat

Thanks for all your excellent suggestions.As it turns out, further close exam
of the system revealed a very small valve on the firewall side of both inlet
and outflow hoses, difficult to see and reach. Finally able to open them and presto, plenty of heat. Real question now is, what reason would someone have had to shut down the flow? I see no leaks so far.

[Duke W.]

Re: C2- no heat

Since water normally flows through the core all the times on non-a/c cars, it's not a bad idea to install a shut off valve as it will keep the interior cooler in hot summer weather. If the core is okay, just leave it there. You'll probably appreciate it next summer.

If you can figure out the manufacturer and model of the valve, I'd like to know as I am looking for an unobstrusive valve to install on my SWC.

Duke

[john pickens]

Re: C2- no heat

For Duke,
I will try to see if I can i.d. a manufacturer or number. Hard to see-will
need to try a small mirror. Thanks again.