C5 Overheating in AZ
Thread Starter
Cruising
Joined: May 2019
Posts: 13
Likes: 2
C5 Overheating in AZ
Hey fellow Vetters, I'm really stumped as to why my '01 Base model keeps running hot. After I sprung a leak in the radiator, I replaced the radiator with a stock replacement, along with the thermostat and new hoses. I filled the system with 1/2 gallon of 50/50 coolant, 2 gallons of distilled water and 8 oz.s of Water Wetter. I had used this product in the past and it dropped the coolant operating temps by at least 15 degrees. I have drove the car several times since and the reservoir remains full with no signs of leakage. Granted it's 110 degrees during the heat of the day but the car seems to slowly, gradually warm up the temp to 240. All replies will be appreciated.
Safety Car
Joined: Dec 2018
Posts: 4,529
Likes: 41
From: CA
C5 of Year Finalist (stock) 2019
St. Jude Donor '19-'20
I put two gallons of undiluted 100% Dex Cool in my radiator and a half a gallon of water in my reservoir after replacing my radiator .stays is nice and cool in hundred degree Heat.
1/4 mile/AutoX
Joined: Jun 2014
Posts: 11,442
Likes: 2,187
From: Buffalo Texas
did you do this ???
Fill the cooling system through the surge tank.
Fill the cooling system with a 50/50 mixture of DEX-COOL® coolant and deionized water.
Start the engine.
Allow the engine to idle for 1 minute.
Install surge tank cap.
Cycle the engine RPMs from idle to 3000 in 30 second intervals until the coolant temperature reaches 99°C (210°F).
Shut off the engine.
Remove the surge tank cap.
Start the engine.
Allow the engine to Idle for 1 minute. Fill the surge tank to 12.7 mm (0.5 in) above the COLD FULL mark on the surge tank.
Install the surge tank cap.
Cycle the engine RPMs from idle to 3000 in 30 second intervals until the coolant reaches 99°C (210°F).
Shut off the engine.
Remove the surge tank cap.
Top off the coolant as necessary, 12.7 mm (0.5 in) above FULL COLD mark on the surge tank.
Rinse away any excess coolant from the engine and the engine compartment.
Inspect the concentration of the engine coolant.
Install the surge tank cap
Fill the cooling system through the surge tank.
Fill the cooling system with a 50/50 mixture of DEX-COOL® coolant and deionized water.
Start the engine.
Allow the engine to idle for 1 minute.
Install surge tank cap.
Cycle the engine RPMs from idle to 3000 in 30 second intervals until the coolant temperature reaches 99°C (210°F).
Shut off the engine.
Remove the surge tank cap.
Start the engine.
Allow the engine to Idle for 1 minute. Fill the surge tank to 12.7 mm (0.5 in) above the COLD FULL mark on the surge tank.
Install the surge tank cap.
Cycle the engine RPMs from idle to 3000 in 30 second intervals until the coolant reaches 99°C (210°F).
Shut off the engine.
Remove the surge tank cap.
Top off the coolant as necessary, 12.7 mm (0.5 in) above FULL COLD mark on the surge tank.
Rinse away any excess coolant from the engine and the engine compartment.
Inspect the concentration of the engine coolant.
Install the surge tank cap
Last edited by Pounder; Jul 29, 2019 at 10:33 AM.
Tech Contributor
Joined: Dec 1999
Posts: 32,910
Likes: 2,402
From: Anthony TX
CI 6,7,8,9,11 Vet
St. Jude Donor '08
Get a hydrometer and measure the coolant percent. You need a solid 50/50 mixture or maybe a little more to keep the mixture from boiling. GM Changes the reservoir cap from the old 15 pound cap to a new and improved 18 pound cap. Highly recommend getting that cap if yours is the old 15 pound cap.
What do you consider RUNNING HOT? 200-230 is NOT out of the norm for a LS engine.
Our blocks can become air bound and cause cooling issues. Have you burped the block using the steam cross over fittings at the front of the heads? That is easy, free and it helps.
Bill
What do you consider RUNNING HOT? 200-230 is NOT out of the norm for a LS engine.
Our blocks can become air bound and cause cooling issues. Have you burped the block using the steam cross over fittings at the front of the heads? That is easy, free and it helps.
Bill
Last edited by Bill Curlee; Jul 29, 2019 at 12:28 PM.
Thread Starter
Cruising
Joined: May 2019
Posts: 13
Likes: 2
Thanks for your reply. I drove the car yesterday in stop and go traffic, 110 degrees in the afternoon, and it warmed up to 240. Can you describe or send a link how to burp the block at the crossover? I’m not familiar with that...Thanks
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Race Director
Joined: Apr 2010
Posts: 16,253
Likes: 1,657
From: Arizona
You must be up toward Phoenix. I am south of Tucson at 4,700 feet and zero issues. Even in Tucson the Vette will get warm but not that warm.
Let us know what works for you or if you will be moving to Alaska. Hahaha
Let us know what works for you or if you will be moving to Alaska. Hahaha
Thread Starter
Cruising
Joined: May 2019
Posts: 13
Likes: 2
I just changed back to 50/50 mix coolant and drove it for about 1/2 hour in city traffic and it finished at 235 degrees. Fans were running when I stopped at home idling. Burped coolant from the block at cross over and reservoir and system seem to be full. Guess I’m still stumped
Drifting
Joined: Jul 2015
Posts: 1,844
Likes: 375
From: San Jose, CA
Specialk70: Do your temps climb to 235-240F during highway driving, street driving, or idling?
STRMLNE: Same question, since you're in the same area. You don't see above 228F. Highway, street, idle?
At 110F ambient, I would not be totally surprised at 240F hot idle, but I'd consider 240F too high if you're doing 75mph in 6th gear.
(Actually, are both of you running 6-speeds? The automatic will likely run hotter due to the trans cooler portion of the radiator, if I understand correctly.)
STRMLNE: Same question, since you're in the same area. You don't see above 228F. Highway, street, idle?
At 110F ambient, I would not be totally surprised at 240F hot idle, but I'd consider 240F too high if you're doing 75mph in 6th gear.
(Actually, are both of you running 6-speeds? The automatic will likely run hotter due to the trans cooler portion of the radiator, if I understand correctly.)