93 not getting warm inside

[Lyndon S.]

I have a friend that just got a low mileage 93. I know nothing about the C4s from that time frame. He said that the heater does not feel like it gets hot enough in the cabin. I ask him if it had plenty of water, he said yes, well I said maybe it is a stopped up heater core. Then I got to thinking that car has the small block with the reverse flow cooling right? I said maybe that could be the reason it dose not get warm in the cabin? Is that a possibility on those particular years, I would think that would not really make that much of a difference. Any one got any other ideas on a 93 that want warm the car?

________
Kelly

[Joe L.]

Re: 93 not getting warm inside

I have a friend that just got a low mileage 93. I know nothing about the C4s from that time frame. He said that the heater does not feel like it gets hot enough in the cabin. I ask him if it had plenty of water, he said yes, well I said maybe it is a stopped up heater core. Then I got to thinking that car has the small block with the reverse flow cooling right? I said maybe that could be the reason it dose not get warm in the cabin? Is that a possibility on those particular years, I would think that would not really make that much of a difference. Any one got any other ideas on a 93 that want warm the car?

________
Kelly

Kelly-----


Believe me, the reverse flow cooling has absolutely no effect on the ability of a 92-96 Corvette heater to provide enough heat. My 1992 will quickly heat the cabin to uncomfortable levels.

Assuming the car has C68 electronic A/C controls, which the vast majority of 92-93 Corvettes had, I'd suspect a possible problem with the controller. These controllers can be problematic. I doubt the problem is with the heater core, itself, and the owner better hope that's not where the problem lies. One DOES NOT want to need a heater core replacement on a C4.

However, the best thing to do to diagnose the actual problem is to follow the diagnostic procedure spelled out in the 1993 Corvette Service Manual.

[Wayne W.]

Re: 93 not getting warm inside

There are three basic electronic controls, the module on the center console, the servo on the RH duct assembly, and a module on the firewall about where you right toe is pointing when driving the car. The last is the most common trouble area. If you take it off and take it appart, you will likely see bad solder joints on some of the connections. Resolder usually takes care of the problem.

[Terry M.]

Re: 93 not getting warm inside

Feel the heater hoses when the engine is at operating temperature and see if the hoses are hot.

When that engine is used in B-body cars there is a flow restriction engineered into one of the heater lines. It is a black plastic cylinder, one end of which is attached to the heater hose with a crimped fitting (like and AC hose), the other end of which uses a hose clamp. It has an arrow on it indicating the direction of flow. I can't tell you for sure the connections are the same for a Corvette, but ....

Chevrolet loved to put sealant pellets, similar to Stop Leak, into the cooling systems of these cars. That material accumulates in the heater core and in this flow restriction.

Disconnect the heater hoses at this flow restriction, and at the "T" to the coolant expansion tank and flush the heater hoses and core well. Use a garden hose pushing into each hose in turn. If you can use hot water it will be more effective.

While you are at it give the expansion tank, engine and radiator a good flushing as well. Fill it back up with the recommended coolant, burp the air out of the cooling system (which is a separate story in itself), and be happy. This works all the time for B-bodies, and I believe there are enough similarities in the cooling systems to make it worth considering for the Corvette.

[Lyndon S.]

Re: 93 not getting warm inside

[Paul H.]

Re: 93 not getting warm inside

What is the operating temperature of the engine when it's warmed up? If it has a 160 thermostat and a fan programmed to come on around 170 (which alot of people did on C4's) the car will run cool in colder weather and not provide enough heat in the cabin. My last C4 did this. The previous owner had installed the 160 thermo and reprogammed the fan. The car ran about 165-170 in the winter and threw lukewarm air when the heat was on.