heat in cockpit c5 vette

not really.. you didnt say if the heater controll valve was working as it should...im guessing it is...also where do you live?.what type of heat is it...water...rotating...exhaust..try and jack it up and put heat insulation around exhaust/floor board..for starters

so shutting the heater would not help ?

Even in summer you may need the heater to clear off the windshields. Corvettes are known to be hot inside. They don't stop the road heat or engine heat from entering the cockpit. When I redid my interior, I put in a heat/noise insulation layer under the floor mats. It helped. It is a heat shield. Normally the hot water is turned off at the heater and does not flow so there is little or no heat from the coolant getting into the cockpit.

The majority of the heat comes from the exhaust pipes that run under the cockpit. Check and see if the heat shield is in place the start placing the heat and noise insulation. I'm working on that also but I don't take many log trips in my 2002 Vette and it never builds until about 45-60 minutes. Good luck.

A bit of disagreement here my friend. The majority of the heat comes not only from the exhaust but the engine and roadway. The fiberglass does not block the heat as metal does, and on hot highways, the heat will warm the cabin quite a bit. I always wondered why the C-2 and C-3 Corvettes did not have better fresh air vents. Putting a heat and sound suppressor coating under the mats helps a lot in not only reducing engine and exhaust noise, but radiated heat as well for all sources. I've spent thousands of miles in a C-2 w/out air and C-3 w/Air to know.

So either way the heat and sound suppressor under the carpet will help no matter the source.

Yes unless you have your heater on and the A/C off on a hot day. It is like insulation in your home. It will slow down and lessen the heat transfer into the cabin. It is best to use the product that is placed under the carpeting and not under the cabin exposed to the outside elements. Go on line and type in "heat shield for cars". This will give you some information, ideas of cost and different products out there. It's insulation for heat and sound. It works for me and all that I know that use it. You will not be sorry.

C2's have constant flowing water to the heater core. I am hearing of people putting in valves to shut the water off in Summer, but doesn't this shut off the expansion tank as well?