overheating.......
Tech Contributor
Joined: Dec 2003
Posts: 19,384
Likes: 87
From: Horncastle Lincolnshire, England
2023 C5 of the Year Finalist - Unmodified
Bill beat me to it but look up into the radiator. The Vette takes air from under the car using the center deflector dam. Make sure no one took that off for starters. Give the radiator intake a good clean out getting rid of any debris.
The cooling fans don't kick in until 230 degrees and I'd see those temperatures regularly in Summer in Vegas.
The cooling fans don't kick in until 230 degrees and I'd see those temperatures regularly in Summer in Vegas.
Thread Starter
Pro
Joined: Oct 2006
Posts: 609
Likes: 0
From: Kentucky
it has a brand new radiator. Would replacing the thermostat with a lower degree help? I replaced it with a 186 degree. It only starts to run hot at about 70mph. It reach almost 240 at one time. Cruising around, it never gets too hot.
Corvette Stories
The Best of Corvette for Corvette Enthusiasts
2027 Corvette vs The World: Every Model vs Closest Competitor
Joe Kucinski
10 Most Common Corvette Problems of the Last 20 Years!
Joe Kucinski
5 MOST and 5 LEAST Popular Corvette Model Years in History!
Joe Kucinski
2027 Corvette Buyer's Guide: Everything You Need to Know!
Joe Kucinski
10 Things C8 Corvette Owners Hate (But Won't Tell You)
Joe Kucinski
10 Best Corvettes Coming to Barrett-Jackson Palm Beach 2026!
Brett Foote
Every Corvette Grand Sport Explained! (C2, C4, C6, C7, & C8)
Joe Kucinski
Grand Sport & Grand Sport X Launch Alongside All-New 535hp LS6 V8!
Michael S. Palmer
5 Reasons Bad Drivers Crash & 5 Ways to Avoid a Costly Mistake!
Joe Kucinski
Thread Starter
Pro
Joined: Oct 2006
Posts: 609
Likes: 0
From: Kentucky
ky, and almost broke.......lol I'm a young gun and new to the LS1 vette engine. Can a dealership do a tune? Where I live, there's not much knowledge in regular shops about newer models. The ones that do know and have the experience, usually work in the dealerships. How much do they usually charge?
Drifting
Joined: Apr 2008
Posts: 1,316
Likes: 2
From: St. Louis Mo
Do the electric fan "modification" to manually turn on your fans. I saw it in a few places including "Ranger" s website.(a forum member that s an excellent driver). Maybe someone else ll give u a link to this...-Jason 
Pro
Joined: Aug 2009
Posts: 662
Likes: 0
From: Loxahatchee FL
first try what was said to others, i replaced the harmonic balancer and starting getting temps around 230 when sitting still and 200-220 when driving high way. i put the car up on lift and holy moly the amount of grass and pebbles in the condenser and radiator cooling vents. it took me an hour to air gun and water pressure to clean it out. dropped the temp 25 degrees stayed under 200 still and driving.
Race Director
Joined: Mar 2008
Posts: 12,413
Likes: 501
From: Rio Rancho NM
taken from another thread
230-240 F doesn't seem that high, check this out:
C5 Cooling Fans Operation
The low speed cooling fan is commanded on when the coolant temperature reaches 108°C (226°F). It is turned off if the coolant temperature lowers to 104°C (219°F). The high speed cooling fan is commanded on when the coolant temperature reaches 113°C (235°F). It is turned off if the coolant temperature lowers to 108°C (226°F). When the A/C is on and the coolant temperature reaches 85°C (185°F), the low speed cooling fan will be turned on at vehicle speeds less than 56 kPh (35 mph).
When you have "cooling problems" always check the radiator for foreign material (grass, leaves, plastic bags, etc.), since these C5s are bottom breathers, they act as road vacuum cleaners.
Be careful, with a leak, if air gets in the radiator, Dexcool turns to a muddy, thick brown and can foul up the cooling system.
230-240 F doesn't seem that high, check this out:
C5 Cooling Fans Operation
The low speed cooling fan is commanded on when the coolant temperature reaches 108°C (226°F). It is turned off if the coolant temperature lowers to 104°C (219°F). The high speed cooling fan is commanded on when the coolant temperature reaches 113°C (235°F). It is turned off if the coolant temperature lowers to 108°C (226°F). When the A/C is on and the coolant temperature reaches 85°C (185°F), the low speed cooling fan will be turned on at vehicle speeds less than 56 kPh (35 mph).
When you have "cooling problems" always check the radiator for foreign material (grass, leaves, plastic bags, etc.), since these C5s are bottom breathers, they act as road vacuum cleaners.
Be careful, with a leak, if air gets in the radiator, Dexcool turns to a muddy, thick brown and can foul up the cooling system.
Pro
Joined: Aug 2009
Posts: 662
Likes: 0
From: Loxahatchee FL
Not sure what the book says as I don't have one but I can tell you mine is stock. Thermostat opens about 180 low speed comes on just after don't see the hight speed come on unless AC is on. Also how it works on my 300C. In any case car runs at 194 after the cleaning compaired to 220-230 and never hits 220 in traffic anymore
fall can be really bad with the leaves too. 
