Running Hot
Thread Starter
7th Gear
Joined: Sep 2019
Posts: 7
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Running Hot
Second thing today, on my 92 Corvette. Car runs pretty hot sometimes around 225 to 230 degrees. I am thinking changing the thermostat to a 180 and flushing the system. Already made sure it is clear if front under the hood and that both fans are kicking in. Anyone else experience this ? Are those temps normal ?
Racer
Joined: Jun 2016
Posts: 292
Likes: 39
From: San Anselmo California
Our 92 did the same thing so I ordered a new thermostat. When I was installing it I noticed someone who put the last thermostat in was unclear on how to do it and slopped a bunch of gasket sealer around it causing the thermostat to not fully open. After I cleaned everything up and installed the new thermostat without gasket sealer the car runs around 190°. Our 92’s use a special thermostat that doesn’t need gasket sealer.
Drifting
Joined: Sep 2009
Posts: 1,765
Likes: 1,507
From: Willis, tx
A properly operating thermostat doesn't have anything to do with high temps. It brings the engine up to operating temp, then the radiator/air flow keeps the engine from getting too hot.
Expect a slow moving C4, in hot weather, with AC to run 220-230.
Expect a slow moving C4, in hot weather, with AC to run 220-230.
Last edited by polo91; Aug 7, 2021 at 01:20 PM.
Drifting
Joined: Nov 2018
Posts: 1,800
Likes: 579
From: Mays Landing, NJ
Second thing today, on my 92 Corvette. Car runs pretty hot sometimes around 225 to 230 degrees. I am thinking changing the thermostat to a 180 and flushing the system. Already made sure it is clear if front under the hood and that both fans are kicking in. Anyone else experience this ? Are those temps normal ?
Last edited by CorvetteRules; Aug 7, 2021 at 01:28 PM.
Melting Slicks
Joined: May 2019
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From: Mid-Atlantic
2025 C4 of the Year Finalist - Unmodified
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My '90 runs 240 degrees on average in stop and go traffic all summer long.
Then cools down as the car gets moving.
I go by the digital temp display versus the analogue one.
Just have to remember the celsius to fahrenheit conversion in your head. After a while it's just second nature.
I haven't had any problems.
Then cools down as the car gets moving.
I go by the digital temp display versus the analogue one.
Just have to remember the celsius to fahrenheit conversion in your head. After a while it's just second nature.
I haven't had any problems.
Racer
Joined: Jun 2016
Posts: 292
Likes: 39
From: San Anselmo California
A malfunctioning thermostat can cause high temps when there’s so much gasket glue that it only opens up about a quarter of the way, it never opens up fully and allows the water to circulate. My temperatures went from 230s down to 190, so it helped in my case.
Melting Slicks
Joined: Oct 2016
Posts: 2,024
Likes: 363
From: Central Alabama
To the OP, if the system is working right it does the job. Don't know the history on yours. Removing debris, is agood start, as mentioned, spoiler in palce is important, my center was mising the support and fixing that helped. original radiator may be partially blocked. So flushing and inspecting for rust and scaling is important. If water pump is original it could have deteriorated blades.
I completly revamped my cooling ssytem the first summer I owned it. All hoses, new radiator, pump, thermostat, TB bypass, new knock sensors. Had to poke throguh the sediment to get the block drained. I have not had issues since.
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Advanced
Joined: May 2021
Posts: 80
Likes: 23
From: NY
My 91 does the same thing. New T-stat, water pump, coolant, radiator hoses.
The heater core bypass line was kinked. Not sure if that had anything to do with it, but I just took it for a quick spin with the core fixed and didn’t get near 200°F when at idle.
The heater core bypass line was kinked. Not sure if that had anything to do with it, but I just took it for a quick spin with the core fixed and didn’t get near 200°F when at idle.
Le Mans Master
Joined: Jul 2004
Posts: 6,228
Likes: 698
From: Clifton Park, NY ............Clearwater, FL ... 85 Original Owner
Second thing today, on my 92 Corvette. Car runs pretty hot sometimes around 225 to 230 degrees. I am thinking changing the thermostat to a 180 and flushing the system. Already made sure it is clear if front under the hood and that both fans are kicking in. Anyone else experience this ? Are those temps normal ?
You should take the radiator out of the car. It's the only true way to clean it right. You can't see how clogged up it is until you do.
Drifting
Joined: Sep 2009
Posts: 1,765
Likes: 1,507
From: Willis, tx
Cleaning a C4 radiator should be done regularly, it's amazing the crap they pick up.
Le Mans Master
Joined: Oct 2004
Posts: 7,706
Likes: 485
From: Everett WA
C4 of Year Finalist (appearance mods) 2019
For the OP this sticky at the top of the page is a very good read:
https://www.corvetteforum.com/forums...peratures.html
https://www.corvetteforum.com/forums...peratures.html
