Car overheats at speed
Thread Starter
Le Mans Master
Joined: Oct 2000
Posts: 6,209
Likes: 33
From: Texas-out west
Car overheats at speed
Car has small hipo motor, runs cool with airco on in town all day long, but at 65 + in runs right up to redzone or 250 degrees. It has new clutch fan. Car is high mileage with over 200K on motor. Ideas? Thanks.
Pro
Joined: Jun 2000
Posts: 569
Likes: 0
From: phoenix az
Re: Car overheats at speed (LT1driver)
Mine was doing the exact same thing. I had the radiator rodded, a high volume water pump, removed thermostat, nothing helped. I dont know why but the only thing that fixed it was an aluminum radiator.
Safety Car
Joined: Jun 2001
Posts: 4,004
Likes: 2
From: Severna Park Md
Re: Car overheats at speed (LT1driver)
I had a car that did this once before. I tried everything in the book to solve the problem except rodding the rad. Most likely the radiator tubes are plugged internally. Also could be excessive debris and bugs and whatnot clogging the rad fins, not allowing the air to pass thru the rad. Drain a small amount of coolant from the rad and look down into the cap opening with a flaslight. If you see lots of crud and build up comming out of the tubes its probably time to pull it and send it in for a rodding or a new core. You might find that a new rad is a better choice.
Race Director
Joined: Apr 1999
Posts: 10,866
Likes: 717
From: Beverly Hills/Pine Ridge Florida
Re: Car overheats at speed (lou)
Is the front air dam in place? Are the seals in place around the radiator and shroud? Overheating at speed could be caused by these items. Chuck
Team Owner
Joined: Jul 1999
Posts: 65,492
Likes: 230
From: Orange Park Florida
Re: Car overheats at speed (LT1driver)
I did all of the above suggestions but on my '72, the cure was removing the front tag and frame...revealing the egg crate grill in the center....
that increased front airflow about 30%....problem solved....
of course in Md. youneed go illegal without a front tag, but it's a minor offense and not likely to be noticed....I drove a '70 Lemans/GTO like that for years up there....
GENE
that increased front airflow about 30%....problem solved....
of course in Md. youneed go illegal without a front tag, but it's a minor offense and not likely to be noticed....I drove a '70 Lemans/GTO like that for years up there....
GENE
Melting Slicks
Joined: Feb 2001
Posts: 2,562
Likes: 1
From: (Temporarily) Colorado Springs Colorado
Re: Car overheats at speed (mrvette)
I'm with Chuck on this one. If it doesn't overheat in traffic and low speeds, the basic cooling system must be in marginally good condition. At higher speeds all air must be directed through the radiator. You must have the lower air dam, and all radiator seals in place. Make sure the upper one makes a complete seal with your hood.
Good luck and keep us informed.
Good luck and keep us informed.
Race Director
Joined: Feb 1999
Posts: 16,978
Likes: 7
From: In Dreams There Is Truth Ohio
Re: Car overheats at speed (The Wanderer)
End of june I got the 533 running. Putzing around town it was fine, on the open highway it shot up to a steady 230.
Problem was the cooling fins, on the bottom part of the radiator, had seperated from the core. Got a new core, dual fans, was running below 180, I put back the front license frame bracket and plate. Now it runs a steady 180. :cheers:
Problem was the cooling fins, on the bottom part of the radiator, had seperated from the core. Got a new core, dual fans, was running below 180, I put back the front license frame bracket and plate. Now it runs a steady 180. :cheers:
Corvette Stories
The Best of Corvette for Corvette Enthusiasts
Top 10 Most Expensive Corvettes Ever Sold on Bring A Trailer
Brett Foote
10 Things Every Corvette Owner Needs (2026 Edition)
Michael S. Palmer
8 Most "Only Corvette Owners Understand" Quirks and Problems
Pouria Savadkouei
10 Reasons the C6 Z06 is Still A Performance Benchmark After 20 Years
Joe Kucinski
How Much Horsepower Every Corvette Engine "LOST" in 1972
Joe Kucinski
Top 10 DOs and DON'Ts for Protecting Your Convertible Top!
Michael S. Palmer
Top 10 Most Explosive Corvettes Ever Made: Power-to-Weight Ratio Ranked!
Joe Kucinski
150 hp to 1,250 hp: Every Corvette Generation Compared by the Specs That Matter
Joe Kucinski
8 Coolest Corvette Pace Cars (and Replicas) of All Time
Verdad Gallardo
Thread Starter
Le Mans Master
Joined: Oct 2000
Posts: 6,209
Likes: 33
From: Texas-out west
Re: Car overheats at speed (GDaina)
Thanks for the comments, I will try the radiator first since the water pump was changed not to long ago, I will let you know what works. Thanks.
Mike
Mike
Thread Starter
Le Mans Master
Joined: Oct 2000
Posts: 6,209
Likes: 33
From: Texas-out west
Re: Car overheats at speed (yellow 72)
Thanks all, I changed the lower hose and the problem seems to have been solved. I will take a 3 hour trip this weekend to confirm. Thanks again. :D
