Low coolant
Thread Starter
Racer
Joined: Jul 2005
Posts: 362
Likes: 1
From: Montreal quebec
Low coolant
I've had my 1986 vette for 6 weeks.
It works great. Only has 32k miles.
But it oftens tell me I'm low in coolant. Althought the overflow is over the line when cold and hot.
what might be the problem?
thanks
Also... when the low coolant light turns on... the sound telling it lights up is a very light metallic sound... very very low and creepy. What's the usual sound?
PS... the car didn't overheat yet... I drove for an hour and it stayed a 195. Although it was only 28F outside
It works great. Only has 32k miles.
But it oftens tell me I'm low in coolant. Althought the overflow is over the line when cold and hot.
what might be the problem?
thanks
Also... when the low coolant light turns on... the sound telling it lights up is a very light metallic sound... very very low and creepy. What's the usual sound?
PS... the car didn't overheat yet... I drove for an hour and it stayed a 195. Although it was only 28F outside
Last edited by lange; Mar 6, 2006 at 09:12 PM.
Team Owner
Joined: Sep 2001
Posts: 62,160
Likes: 1,733
From: Athens AL
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The thermostat opens at 195 if stock, so if its holding there then its at least opening, but the fact that its getting this hot in that weather tells me that something else might be up.
The first culprit will be the radiator cap, if you havent replaced it. Then burp the system by letting the engine warm up to the stat opening temp with the cap off, and then holding it to 2000rpm while filling the fluid. (buy the 50/50 premixed coolant) This may only be a temporary fix, if theres a leak then it'll come back on eventually.
Inspect for leaks EVERYWHERE, all hose connections, WP, anything.
In my case, and I'm having this very problem right now, it appears to be a busted radiator. Stop Leak products are not a permanent fix, and it can be leaking without ever putting a drop on the ground....small leaks will let vapors out when the radiator gets hot.
The first culprit will be the radiator cap, if you havent replaced it. Then burp the system by letting the engine warm up to the stat opening temp with the cap off, and then holding it to 2000rpm while filling the fluid. (buy the 50/50 premixed coolant) This may only be a temporary fix, if theres a leak then it'll come back on eventually.
Inspect for leaks EVERYWHERE, all hose connections, WP, anything.
In my case, and I'm having this very problem right now, it appears to be a busted radiator. Stop Leak products are not a permanent fix, and it can be leaking without ever putting a drop on the ground....small leaks will let vapors out when the radiator gets hot.
Safety Car
Joined: Sep 2002
Posts: 4,971
Likes: 9
From: The reason time exists is so everything doesn't happen at once
You have to burp the air out of the cooling system. When the engine is cool open the top expansion tank and start the engine. As the coolant level drops add more coolant until the level in the expansion tank doesn't drop anymore. Then put the pressure cap back on and after the engine cools slowly open the air bleeder valves on the throttle body and water pump inlet. PUt towels around the valves so you don't spray coolant all over the place.
Drifting
Joined: Jun 2001
Posts: 1,997
Likes: 1
From: Lake Ozark MO
Overflow is full but the reservoir is not. That's what gives you the low coolant light (low reservoir level).
Replace the radiator cap. The old one has probably crapped out and is letting fluid release to the overflow tank.
Replace the radiator cap. The old one has probably crapped out and is letting fluid release to the overflow tank.
Burning Brakes
Joined: May 2004
Posts: 1,230
Likes: 27
From: Athens Ohio
I have an 86 also. Mine did the same thing. I went through the burping proceedure many times. It would last for a little while. I had no leaks anywhere. I finally drilled a small hole in the body of the thrmostate and the problem was solved. I hope this helps.
Melting Slicks
Joined: Jan 2002
Posts: 2,531
Likes: 35
From: Lecanto Florida
I had the "Low Coolant" light on for awhile and used the procedures I got from this forum for burping the engine/radiator. Big thing is to keep the revs up when the thermostat opens up. The water gets sucked up into the engine and you can fill the radiator to the top and put the cap on before you let the revs drop. Worked for me and haven't seen the Low Coolant light again.
but make sure you have no leaks 
