Inside is SO HOT!!!
Thread Starter
Racer
Joined: Apr 2006
Posts: 297
Likes: 0
From: Houston Texas
Inside is SO HOT!!!
Myvette runs smooth and doesn t overheat at all but after driving for about 30 mn i start feeling a lot of hot air by the pedals. Also, the sides (plastic) of the radio and the carpet, and under wheel is VERY HOT!!! which makes the entire car warm even with the AC full blast. Is this normal? what can I do? help!!! I live in Houston!!! it's always too hot already!! 
Intermediate
Joined: Oct 2005
Posts: 46
Likes: 0
From: Vikersund
This is a common problem with the most of Corvettes. The hot air flaps are not hermetic or in malfunction. The temporary solution of this problem is to built in a valve in the heater hose. Reparation of the heather/AC system is a bigger job. Unfortunely have I to make this job on my Corvette too!
Racer
Joined: Dec 2004
Posts: 379
Likes: 0
From: Fairfield Texas
You might want to check and see if foam collar is still on top of
bellhousing.This helps keep the engine heat from going into the trans.
tunnel. One thing I did that helped with cabin heat was put a manual
cutoff valve in the heater hose.The factory vacuum operated valve
is nortorious for leaking hot water into heater core. Of course there is
always the option of adding insulation under the carpet.
bellhousing.This helps keep the engine heat from going into the trans.
tunnel. One thing I did that helped with cabin heat was put a manual
cutoff valve in the heater hose.The factory vacuum operated valve
is nortorious for leaking hot water into heater core. Of course there is
always the option of adding insulation under the carpet.
Pro
Joined: Oct 2003
Posts: 641
Likes: 2
From: Storm lake Iowa
Safety Car
Joined: Oct 2004
Posts: 3,725
Likes: 5
From: Minnesota
Like the others say, put a manual shutoff valve on the heater hose. Also, you want to be sure the gasket that seals the back of the hood is in good shape to keep the hot engine air out of the air intakes (mine was completely missing
). Another thing is to insulate under the carpet. The last thing I might try is some header heat wrap to lower the under hood temps a little.
). Another thing is to insulate under the carpet. The last thing I might try is some header heat wrap to lower the under hood temps a little.
Thread Starter
Racer
Joined: Apr 2006
Posts: 297
Likes: 0
From: Houston Texas
thanks for ur answers I wuld not trade my c3 for a C5 even if u give me money on top!!! loool
as far as AC I have AC it s blowing cold but the car get so warm under that it cancels it out.
Some were talking aout a shut off valve??? would it affect performance or could it damage my engine?
I wuld not trade my c3 for a C5 even if u give me money on top!!! loool as far as AC I have AC it s blowing cold but the car get so warm under that it cancels it out.
Some were talking aout a shut off valve??? would it affect performance or could it damage my engine?
Racer
Joined: Jun 2004
Posts: 474
Likes: 0
From: Moncks Corner South Carolina
Originally Posted by AGVI
Get a C5 or do what the others said. Actually get some AC!
I had the same problem with my C5. Thought my shoes were going to melt. I pulled the entire interior out and insulated the tunnel and floorboards. Made a huge difference. Probably have to do this to my C3 also.
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Safety Car
Joined: Oct 2004
Posts: 3,725
Likes: 5
From: Minnesota
You live in Houston? Do you ever use the heat? I'd probably bypass the heater core altogether. One less thing to worry about leaking. Just run a hose from the pump to the thermostat housing. If you really want to put in a valve most any auto parts store should have one. It'll screw into the thermostat housing.
Burning Brakes
Joined: Jan 2004
Posts: 769
Likes: 0
From: Ft. Lauderdale Fl
Try side pipes
I drive all year round here in South Florida and my feet never get hot. Short headers pipe goes right outboard and never goes under the driver and passenger seat. We don't have inspections so no cat is needed. Good luck 
I drive all year round here in South Florida and my feet never get hot. Short headers pipe goes right outboard and never goes under the driver and passenger seat. We don't have inspections so no cat is needed. Good luck
Instructor
Joined: Dec 2005
Posts: 190
Likes: 0
From: Hot AZ
I had the same problem with my 78 since new 
Then I found out the temperature control lever cable has a white plastic adjustment control about 10-12 inches from the leaver attachment point. It is located on the pass side of the console. What it does is lengthens or shortens the cable to adjust the air diverter in the a/c - heater plenum. Mine wasn't adjusted correctly from the factory and allowed hot air to mix with the outside air. After I adjusted it to make sure the diverter valve was close with the temp lever all the way to cold...no more hot air always blowing 
Well, that is when its not 100 degrees in AZ anyway. The a/c even works better too! Check it out before you do any of the major surgery you might get lucky 
Then I found out the temperature control lever cable has a white plastic adjustment control about 10-12 inches from the leaver attachment point. It is located on the pass side of the console. What it does is lengthens or shortens the cable to adjust the air diverter in the a/c - heater plenum. Mine wasn't adjusted correctly from the factory and allowed hot air to mix with the outside air. After I adjusted it to make sure the diverter valve was close with the temp lever all the way to cold...no more hot air always blowing Well, that is when its not 100 degrees in AZ anyway. The a/c even works better too! Check it out before you do any of the major surgery you might get lucky
Instructor
Joined: Dec 2005
Posts: 103
Likes: 0
From: Pittsburgh PA
Originally Posted by chevylit
You might want to check and see if foam collar is still on top of
bellhousing.This helps keep the engine heat from going into the trans.
tunnel. One thing I did that helped with cabin heat was put a manual
cutoff valve in the heater hose.The factory vacuum operated valve
is nortorious for leaking hot water into heater core. Of course there is
always the option of adding insulation under the carpet.
bellhousing.This helps keep the engine heat from going into the trans.
tunnel. One thing I did that helped with cabin heat was put a manual
cutoff valve in the heater hose.The factory vacuum operated valve
is nortorious for leaking hot water into heater core. Of course there is
always the option of adding insulation under the carpet.
Melting Slicks
Joined: Dec 2005
Posts: 2,441
Likes: 0
Check all the rubber grommets in your firewall. They can let in allot of hot engine air if they're missing.
A heater core shutoff valve won't hurt the engine in any way, it merely stops the hot engine coolant from circulating through the heater core, so if you've got ventilation valve problems under the dash, at least you won't have any hot air being generated by the heater.
A heater core shutoff valve won't hurt the engine in any way, it merely stops the hot engine coolant from circulating through the heater core, so if you've got ventilation valve problems under the dash, at least you won't have any hot air being generated by the heater.
Le Mans Master
Joined: Jan 2006
Posts: 9,192
Likes: 27
From: Boca Raton Florida
Read and follow the link above to seal up all the air leaks, thats where most of the heat is comming from, thru holes in the firewall and from the vent on the pass side. Your car might be equiped with a Hot Water Cutoff Valve, it will be on one of the heater hoses right before the firewall, if it is, make sure it works, it is operated by vacuume from the AC control system. If it does not have one, install one, a half inch brass ball valve from Home Depot will do a nice job.
Check on the foam collar that is supposed to be on top of the transmission, if it is missing, use a piece of hot water pipe insulation from Home Depot, cheap fix and it blocks the hot air from off the motor flowing into the tranny tunnel. Last thing is heat thru the floor, this cam be dealt with useing Dynomat, Reflectix, of a bunch of other producs to insulate the floor of the car. Do a search in here and you will find several products that the guys have used.
Check on the foam collar that is supposed to be on top of the transmission, if it is missing, use a piece of hot water pipe insulation from Home Depot, cheap fix and it blocks the hot air from off the motor flowing into the tranny tunnel. Last thing is heat thru the floor, this cam be dealt with useing Dynomat, Reflectix, of a bunch of other producs to insulate the floor of the car. Do a search in here and you will find several products that the guys have used.
Race Director
Joined: Sep 2004
Posts: 11,874
Likes: 263
From: Arlington Va Current ride 04 vert, previous vettes: 69 vert, 77 resto mod
Originally Posted by mdjice
Some were talking aout a shut off valve??? would it affect performance or could it damage my engine?
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Le Mans Master
Joined: Aug 2000
Posts: 6,273
Likes: 14
From: Austin TX
A couple of things that haven't been mentioned:
Replace all boots - two on the shifter, one at clutch, smaller one on accelerator cable and speedo cable
Close all holes - Pull your carpet back from the firewall and have a friend blow compressed air at the firewall from the engine side. Holes in the floor and footwells will show up. Plug 'em.
Add heat shields from a 69
Do all these along with heater hose cutoff and heater door adjustment and insulation under your carpet and you will be much cooler.
Replace all boots - two on the shifter, one at clutch, smaller one on accelerator cable and speedo cable
Close all holes - Pull your carpet back from the firewall and have a friend blow compressed air at the firewall from the engine side. Holes in the floor and footwells will show up. Plug 'em.
Add heat shields from a 69
Do all these along with heater hose cutoff and heater door adjustment and insulation under your carpet and you will be much cooler.
Burning Brakes
Joined: Aug 2005
Posts: 1,126
Likes: 0
From: Hudson Falls, N.Y. 76 Vette Modified L-48
Same problem here (we get your Houston weather up here in NY during the summer)..what I did, put a turn off valve in on the inward flow hose, stopping any hot water from entering the core, then went to Radio Shack, got a couple of rolls of coax seal, sealed around the passenger vent door and plugged and removed the vacuum line to the vent door canister, then, cut a piece of styrofoam to fit the vent door hole and snuggly pushed the piece in (had to remove the canister and the connecting arm, then put the canister back in, not connecting the arm after sealing), then sealed that around the edges...
Have had a few very warm days so far and it's a pleasure to drive again...
That's my story...
Have had a few very warm days so far and it's a pleasure to drive again...
That's my story...
Racer
Joined: Sep 2005
Posts: 453
Likes: 1
From: Austin TX
Bob, what kind of heat sheilding is that and how well does it stick to the undercarriage (has any peeled off)? I assume it was freshly cleaned before you stuck it in there. I would like to insulate underneathe since my engine and tranny are out right now and later on when I do the interior insulate there as well.
