heats up on the highway
Thread Starter
Drifting
Joined: Mar 2002
Posts: 1,877
Likes: 39
From: cincinnati ohio
Cruise-In V Veteran
heats up on the highway
My vette is 75 with air.If i drive 65 mph on the highway for approx 60 miles or more temp starts to climb slowly.It has gone to about 230 degrees.When i drop speed down to around 55 mph temp drops also.Drops to around 200.This only happens when air temp is above 70.I can drive around town in stop and go traffic without any problems-will run about 180 degrees. I have installed new GM radiator changed thermostat from 190 to 160 new belts and hoses.Would like to drive my car to Forum cruise but dont know how high temp would go.I only drive car locally because of this.
Thanks for all help
Thanks for all help
Le Mans Master
Joined: Mar 2002
Posts: 7,456
Likes: 2
From: Coming home from Luckenbach Texas
Re: heats up on the highway (jlsru75)
Check your fan clutch...or get rid of it! Mine was bad -- it got replaced along with much of the A/C system.
In 95 degree weather (what we currently have in the afternoons), my '79 runs about 220 degrees on the freeway. At stoplights, it will climb a little, but goes away when I get going. With the A/C off, she cools down some, but I heat up!
I think this is about the normal operating condition for this car!
[Modified by page62, 3:04 PM 5/2/2002]
In 95 degree weather (what we currently have in the afternoons), my '79 runs about 220 degrees on the freeway. At stoplights, it will climb a little, but goes away when I get going. With the A/C off, she cools down some, but I heat up!
I think this is about the normal operating condition for this car!
[Modified by page62, 3:04 PM 5/2/2002]
Moderator
Joined: Jun 1999
Posts: 7,117
Likes: 51
From: Dove Mountain Arizona
Re: heats up on the highway (jlsru75)
Make sure all the air goes THRU the rad and not around it. All open gaps around the rad/shroud need to be closed off. Helped mine by 20 deg minimum.
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Le Mans Master
Joined: Sep 2000
Posts: 5,635
Likes: 4
From: Orlando Floriduh
Re: heats up on the highway (jlsru75)
It may not be a cooling system problem. It may be the ignition timing. It may not be advancing far enough or not at all. Retarded timing will make an engine run hot. Obviously the higher the RPM the worse that would be. Make sure that the advance portion of the distributor moves. Sometimes the cener shaft gets frozen and the wieghts will not advance the timing. Also check the vacuum advance and related hoses. Check for a plugged catalytic converter also. This will cause overheating big time! :cool:
Burning Brakes
Joined: Nov 2001
Posts: 787
Likes: 1
From: Toronto Ontario
Re: heats up on the highway (silvervetteman)
I went through heel with my vette a few week ago with temp going up to 250F on the hyw and running at 200F in the city, Here is what I did to solve the problem.
1-Get the rad cleaned at a rad shop and do not paint the fins with any paint just leave the black primer the rad shop adds. Most guys like to see their rad look shiny and paint the core and that is a killer
2- install the seals around the rad water pipe insulation works great
3- I removed the elec fans and re-installed the stock rad fan
4- replaced the crazy comp 292h cam with a Crane 272 cam
The 454 is running at 160F with a 160 stat at any speed with the air on, I may have to go upto a 180 stat currently running to cold.
1-Get the rad cleaned at a rad shop and do not paint the fins with any paint just leave the black primer the rad shop adds. Most guys like to see their rad look shiny and paint the core and that is a killer
2- install the seals around the rad water pipe insulation works great
3- I removed the elec fans and re-installed the stock rad fan
4- replaced the crazy comp 292h cam with a Crane 272 cam
The 454 is running at 160F with a 160 stat at any speed with the air on, I may have to go upto a 180 stat currently running to cold.
Melting Slicks
Joined: May 1999
Posts: 2,897
Likes: 0
From: Moon Township PA
Re: heats up on the highway (73-454)
1-Get the rad cleaned at a rad shop and do not paint the fins with any paint just leave the black primer the rad shop adds. Most guys like to see their rad look shiny and paint the core and that is a killer
2- install the seals around the rad water pipe insulation works great
3- I removed the elec fans and re-installed the stock rad fan
4- replaced the crazy comp 292h cam with a Crane 272 cam
The 454 is running at 160F with a 160 stat at any speed with the air on, I may have to go upto a 180 stat currently running to cold.
2- install the seals around the rad water pipe insulation works great
3- I removed the elec fans and re-installed the stock rad fan
4- replaced the crazy comp 292h cam with a Crane 272 cam
The 454 is running at 160F with a 160 stat at any speed with the air on, I may have to go upto a 180 stat currently running to cold.
Gary
Melting Slicks
Joined: Dec 2000
Posts: 3,407
Likes: 2
From: Carmichael CA
Re: heats up on the highway (jlsru75)
I hope you don't have the same problem that I did. My vette was overheating real bad, and for some reason the brakes felt like they were locking up, though they freed up as soon as I pulled off the highway. I finally broke a spindle and upon inspection found that the rear wheel bearings were running without sufficient grease...too much friction was causing excessive drag and thus causing the engine to work harder and overheat. Anyway to make a long story short, all that was done was control arms were rebuilt and now I can cruise at 70 with air conditioning running in 80degree weather and the coolant maxes at 205.
Thread Starter
Drifting
Joined: Mar 2002
Posts: 1,877
Likes: 39
From: cincinnati ohio
Cruise-In V Veteran
Re: heats up on the highway (Rockn-Roll)
Rockn-Roll: I dont wont that problem.My brakes are working fine not locking up so i dont seem to have your systems.
Racer
Joined: May 2001
Posts: 401
Likes: 0
From: Carlsbad CA
Re: heats up on the highway (jlsru75)
I had the same problem in my 4Runner, and only solved it by replacing the radiator (after replacing EVERYTHING else first :mad ). I don't necessarily understand all the thermodynamics involved, but a brand new water pump and four radiator flushes had no effect. I bought a new radiator and dropped it in and have had no problems since then. Hope this helps. I know that a hi-tech engine like the 4Runner automatically adjusts timing, etc, so those can't be ruled out on your Vette, but if all else fails it may be that the radiator isn't flowing to capacity.
