82Powerhouse

1982 Corvette
350 CID
700R4
4-core radiator

I am still having trouble with overheating. I can drive the car at around 45 and the temp will perpendicular on the gauge – around 200 I think, I am not near the car. This takes about 25-30 minutes, but it gets there. If I drive it 65+, then it will eventually burry the needle and start to boil over. I can’t run the AC because it will also bury the needle at any speed. I have replaced all of the listed parts below. I did notice that the hose coming from the thermostat, and the inlet hose from the heater to the water pump were collapsing while it was running hot – not completely, but enough to show there is negative pressure there somewhere. I am not sure what else to try. I have had it flushed several times, but that did nothing as well. Someone did mention that it might have an air pocket in there. If so, then it probably will be in the heads, because I just replaced the water pump and it drained the rest of the engine – I guess. Any help on this would be greatly appreciated.

Parts replaced.

Water pump
All hoses
Thermostat
Radiator is about 1.5 years old.
Fan blade
Fan clutch
Fan relay


The heater core has not been replaced yet, but there was good flow going through it.

TIA,
CDM

Fevre

Do you have a spring in the lower hose? It will collapse if not. I use a universal hose which has molded in ribs but I am running an elec fan and no shroud.

Also check your timing and fuel metering, if you are running retarded timing or lean (or both) it will run hot. Check to see if your vac adv is hooked up.

Cooling issues are not always just cooling system issues

Twin_Turbo

I see you have a high rise hood and a daytona front, is the stock airdam still in place? I noticed the temps soaring after installing my L88 hood, what happens is the incoming air passes over the radiator instead of through it, if you don't have the airdam it'll be even worse because of the majority of air going under the car. I would install a lower scoop if not present and also add a leading edge in the front of the top rail of the radiator frame to force the air through the rad

sly vette

Radiator cap...
Later,
Sly

Calm Screamer2

A collapsed radiator hose can be caused by a defective radiator cap, or the tube going to the coolant reservoir may be clogged. As the engine gets hot, it creates a vacuum which draws coolant from the reservoir. If the path to the reservoir is plugged...then what happens???...the hose will tend to collapse . Hope this helps.

jdp6000

If you can drive at 45 all day long without breaking 200 I'd say Twin Turbo is right on the money. Front spoiler and blocked off at the top of the rad it critical.

I see you broke the 220 mark a couple of times...does your electric fan kick in??? It should.

Do you have a shoud around the fan???

Jim

SIXFOOTER

I agree, Radiator cap is a easy duck. Fix the radiator seals, make sure the lower hose has ribs, Air dam has to be there and in proper shape and shroud has to be there if your running stock fan

terry82

i would take out the thermostatand see what it does .the new thermostat could be bad or you put it in up side down .check it so that you know .if that does not work i would drain the radiator .take off the lower hose and the top hose .then put a garden water hose in the top inlet of the radiator, turn the water on,check the flow coming out at the bottom out let. to make sure that radiator is not pluged .

BerniesVette

If you think you have a vapor lock do this; jack the front of the car up in the air, take the rad cap off making sure it is full of coolant, start the engine and when the water starts to flow, add coolant until it will no longer take it and install the cap. This "burps" the air from the engine. another thing I do is drill a small hole in the thermostat to keep coolant flowing even though the t-stat is closed. Then air isn't allowed to be trapped. As the others stated; check the radiator cap, the thermostat, the hoses especially the lower one that needs a spring in it to keep it from collapsing. And make sure that the area around the radiator anf the adiator support is completely sealed so that air cannot go around the radiator; it must be forced to go thru it. I hope you find the source of your problem.
Bernie

chevymans 77

have you made any changes to the car? If so what were they?

...Roger...

Those hoses on the pressure side of the pump collapsing bothers me,could this be the suction side pulling them down through the radiator backwards because the coolant cant get out of the intake?Thermostat restiction?Like Terry said take the therm. out and try it.

MsVetteMan

Check your timing. Probably running pretty advanced, and may be leaning out due to it.

Back your timing down to 8 or 10 and take it on a cruise....tell me what happens........

82Powerhouse

The radiator cap has been replaced, I just forgot to put that on the list. And I do have an original shroud.

The thermostat is out and there is no difference.

All of this started when I replaced the mech. fan to an electric one. That did not work, and ever since then, I have had this overheating problem. Even with the Daytona front and the twin turbo hood – without any of the air dams, etc. I have replaced the Daytona front with the original. It still does the same – hence the help request.

I will try checking the timing and also raising the front of the car with the cap open to let any possible air out.

johns73

please post a photo of the fron of you engine.

toyvet1

I chased the same problem for a couple years and found out it was a bad intake manifold. After inspecting it I could find no flaws in it. Once I changed out the manifold the problem went away. I also am running a daytona bumper with turbo hood. FYI I am running a TPI engine.

MsVetteMan

Just an off he wall thought.....fan turning the right direction?

Also pull and check a couple of plugs.......really white means lean....and will cause overheating, especially at highway speeds.....been there.

jdp6000

Whats telling the fan to turn on??? Hopefully not the ECM....it tells the stock electric fan to kick in north of 220...its only there as a secondary source of cooling.

Since you have replaced the fan with an electric how did you rig it to turn on at the appropriate time???

Jim

82Powerhouse

I have tried reversing the fan with the same lack of results. The auxillary fan is controlled by a Hayden relay (Hayden or Imperial) and I have it set to turn on at 90 degrees.

Eventually I plan on changing the intake anyway, maybe I should think about doing it sooner than later. It is not stock, it came with the car when I bought it.

I am hoping to have the time to work on it this weekend some. I have not had a chance to do it when I get home - it's too late and I live in an apartment.

Ironcross

I believe the correct thermostat for a 82 is a 195 stat used for the emission controls since the early 70`s for those smog engines. The radiator may not be able to recover fast enough with a low temp stat.

Rockn-Roll

Are you saying that everything was fine with the mechanical fan? If so then consider some aspects of the mechanical fan. For instance it will freewheel at higher engine RPMs so that at higher speeds the fan won't prevent air flow through the radiator. Basically, a fan is there just for low speed and idle air flow. An ideal fan would disappear at about 50MPH. So...perhaps look at other fans and look for some that have more features.