81 vette running hot help
Race Director
Joined: Mar 2008
Posts: 15,161
Likes: 17
From: coffee
Need more info...
Is your engine stock, do you have any non-stock components in your cooling system (fan, shroud, water pump, thermostat, radiator), is the air deflector behind the front fascia still in place?
Is your engine stock, do you have any non-stock components in your cooling system (fan, shroud, water pump, thermostat, radiator), is the air deflector behind the front fascia still in place?
Safety Car
Joined: Mar 2007
Posts: 3,652
Likes: 49
From: Bridgewater nj
If it's running hot but not over heating try...
some of the water additives, like wetter water. They are good for 10 to 20 degrees and it is cheap $10 bucks give or take $. If that doesn't work try Flex-o-lite Dual 27" fans for $235.00, they slide right in perfectly. P.S. if your alternator is old or low amps(under 70 amps) you may have to upgrade.
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Le Mans Master
Joined: Jan 2006
Posts: 9,192
Likes: 27
From: Boca Raton Florida
"HOT" could be different things to different people. Is the Temp gauge reading over 220*? Is it boiling over?
I have dug into this rather extensively on my 81.
Like mentioned above go thru the basics first:
Belts tight (not the problem, it would squeel if it was)
Stock t-stat is 180*, do you know whats in there now?
Radiator seals: all must be in place around the radiator to support, along the top of the air induction to hood seal.
Air Dam must be in place and mot all bent up under the front end from parking curbs.
Fan Clutch: likely culprit here, with the hood up and enging running at temp, turn it off while watching the fan, it should not turn more than 1/2 turn. If it does the clutch is most likely toast.
Fan Shroud, asuming you have the stock one in place, it should be bolted up securely and the fan should be about half way in the back of the shroud.
The 81 has an AUX fan. It is electrical and is a very poor backup device. It is supposed to come on at 238*, way to late and it does not move much air at all.
I have dug into this rather extensively on my 81.
Like mentioned above go thru the basics first:
Belts tight (not the problem, it would squeel if it was)
Stock t-stat is 180*, do you know whats in there now?
Radiator seals: all must be in place around the radiator to support, along the top of the air induction to hood seal.
Air Dam must be in place and mot all bent up under the front end from parking curbs.
Fan Clutch: likely culprit here, with the hood up and enging running at temp, turn it off while watching the fan, it should not turn more than 1/2 turn. If it does the clutch is most likely toast.
Fan Shroud, asuming you have the stock one in place, it should be bolted up securely and the fan should be about half way in the back of the shroud.
The 81 has an AUX fan. It is electrical and is a very poor backup device. It is supposed to come on at 238*, way to late and it does not move much air at all.
Le Mans Master
Joined: Apr 2004
Posts: 7,106
Likes: 38
From: Newark DE
sixfooter, I can't answer specifically on the '81 but most year C3's came stock with a 195º t-stat. This was because of emission requirement and the motors had to run hotter to burn off excess hydrocarbons.
With the factory emission equipment still installed a 195º t-stat should be retained to keep emission levels down. If the emission equipment has been removed from the car or you don't need to pass emission tests in your state than dropping down to a 180º t-stat is good....... not that the t-stat is going to make a difference in what temp the motor will go up anyway, just it's minimum operating temp.
With the factory emission equipment still installed a 195º t-stat should be retained to keep emission levels down. If the emission equipment has been removed from the car or you don't need to pass emission tests in your state than dropping down to a 180º t-stat is good....... not that the t-stat is going to make a difference in what temp the motor will go up anyway, just it's minimum operating temp.
Race Director
Joined: Dec 2007
Posts: 14,345
Likes: 4
From: Hartselle AL
St. Jude Donor '09
Drifting
Joined: Aug 2007
Posts: 1,924
Likes: 6
but, I'm a displaced Bostonian for sure. When I trash talk Massachusetts, it's based on 44 years of experience.
Melting Slicks
Joined: Mar 2006
Posts: 2,465
Likes: 0
From: Orange Park Fl
1. Check that you haven't picked up any road trash (scooped up a Wal-Mart bag off the street that is now laying on the front of your radiator). If you have compressed air, blow out any trash stuck in the radiator.
2. Flush the radiator thouroghly and refill with the minimum amount of old fashion green anti-freeze for the temperatures you experience.
3. Replace the thermostat when you do the flush.
4. Check your ignition timing.
Add two bottles of Redline Water-Wetter and call us in the morning. God bless, Sensei
2. Flush the radiator thouroghly and refill with the minimum amount of old fashion green anti-freeze for the temperatures you experience.
3. Replace the thermostat when you do the flush.
4. Check your ignition timing.
Add two bottles of Redline Water-Wetter and call us in the morning. God bless, Sensei
Drifting
Joined: Apr 2006
Posts: 1,911
Likes: 2
From: gold coast queensland
i like all of six footers advice . if you check all these things you have done most of the basic and important checks. cars run hotter normally when you have aircon on anyway so its normal, it just depends how hot you are talking???? give us some figures on whats going on???
Le Mans Master
Joined: Apr 2004
Posts: 7,106
Likes: 38
From: Newark DE
ali
if you want help you NEED to give us more details and respond with more than just a single sentence.
what temps are you running with and without the AC on.
Are you actually overheating with the coolant pucking out?
do you have ALL the radiator/core support seals in place?
do you have the airdam under the nose in place?
does it run hot all the time with the AC or or just at low speed/idle or just on the highway?
you are asking us to help you but you are not giving us information to work with.
Oh, and put your t-stat back in!
if you want help you NEED to give us more details and respond with more than just a single sentence.
what temps are you running with and without the AC on.
Are you actually overheating with the coolant pucking out?
do you have ALL the radiator/core support seals in place?
do you have the airdam under the nose in place?
does it run hot all the time with the AC or or just at low speed/idle or just on the highway?
you are asking us to help you but you are not giving us information to work with.
Oh, and put your t-stat back in!
Thread Starter
Cruising
Joined: Apr 2008
Posts: 12
Likes: 0
hi,
the vette temp 200with out ac and with ac it is 220.
the water is not pucking out when the car is hot.
it does not starts when the car is hot.
i dont where is the air dam.
it run hot all the time with the AC
the vette temp 200with out ac and with ac it is 220.
the water is not pucking out when the car is hot.
it does not starts when the car is hot.
i dont where is the air dam.
it run hot all the time with the AC