Overheating at idle
Thread Starter
Race Director
Joined: Dec 2005
Posts: 13,515
Likes: 12
From: Fisher, IL
Overheating at idle
My car over heats at idle. reaching redline temp. pretty fast if i'm not moving. I can't tell if the fan kicks on but is there anything else that might be causing this problem? I have fresh antifreeze and all new fluids in my 96 auto LT1. At what temp should my fan kick on and start to work? and if it does kick on what else could it be?
Race Director
Joined: Jan 2004
Posts: 18,727
Likes: 711
From: Bergen County, NJ
I would first find out exactly when the fans come on.
Let it idle with the hood open & see when the main and aux fans come on.
If the fans are OK, then that eliminates them as the problem.
Let it idle with the hood open & see when the main and aux fans come on.
If the fans are OK, then that eliminates them as the problem.
Race Director
Joined: Oct 2005
Posts: 11,772
Likes: 177
From: Rolla Missouri
2021 C4 of the Year - Unmodified Finalist
St. Jude Donor '10 thru '25
The simplest way to make sure the fans actually work is while it's at idle and warming into the 200 degree range, flip on the A/C. The fans should come on. With the A/C off, they should still come on once the temp reaches 228 - 230. If the digital temp gauge reaches above 235 at idle without the fans coming on, then you have a problem.
Instructor
Joined: Feb 2006
Posts: 205
Likes: 0
From: Fraser MI
Just went thru this same issue. You need to burb the cooling
system after changing antifreeze. Works best when cold.
There is a notched bolt just next to the top hose on the right
side of the thermostat. I just opened up a turn or so and started
the engine. Run right back to tighten as antifreeze is coming out.
End of overheating when at idle. I tried this when it was hot without
success. Clean up antifreeze so pets won't get to it.
Craig
system after changing antifreeze. Works best when cold.
There is a notched bolt just next to the top hose on the right
side of the thermostat. I just opened up a turn or so and started
the engine. Run right back to tighten as antifreeze is coming out.
End of overheating when at idle. I tried this when it was hot without
success. Clean up antifreeze so pets won't get to it.
Craig
Le Mans Master
Joined: Jan 2006
Posts: 6,564
Likes: 6
From: Woodstock Georgia
Originally Posted by Craig's Polo '93
Just went thru this same issue. You need to burb the cooling
system after changing antifreeze. Works best when cold.
There is a notched bolt just next to the top hose on the right
side of the thermostat. I just opened up a turn or so and started
the engine. Run right back to tighten as antifreeze is coming out.
End of overheating when at idle. I tried this when it was hot without
success. Clean up antifreeze so pets won't get to it.
Craig
system after changing antifreeze. Works best when cold.
There is a notched bolt just next to the top hose on the right
side of the thermostat. I just opened up a turn or so and started
the engine. Run right back to tighten as antifreeze is coming out.
End of overheating when at idle. I tried this when it was hot without
success. Clean up antifreeze so pets won't get to it.
Craig
Ya gotta get all the air out of the motor. Burp it good!
Thread Starter
Race Director
Joined: Dec 2005
Posts: 13,515
Likes: 12
From: Fisher, IL
i remember doing something like that with the nut and the copper line.....is that what you are talking about? i don't know if i started the car with the line open or if i just opened it and saw that anti-freeze was coming out.
I can do it again but you are saying that i should open it up then start it, then close it?
I can do it again but you are saying that i should open it up then start it, then close it?
Race Director
Joined: Aug 2003
Posts: 13,421
Likes: 8
From: Lake Mary Florida
Originally Posted by tparkhi2
i remember doing something like that with the nut and the copper line.....is that what you are talking about? i don't know if i started the car with the line open or if i just opened it and saw that anti-freeze was coming out.
I can do it again but you are saying that i should open it up then start it, then close it?
I can do it again but you are saying that i should open it up then start it, then close it?
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Le Mans Master
Joined: Jan 2006
Posts: 5,621
Likes: 206
From: Orlando FL
I'm not quite sure if I understand if you just changed the antifreeze or the problem is just occuring. However the driver side cooling fan comes on at 225 deg or whenever the A/C is turned on. The second fan comes on at about 239 deg. Unless your in standstill traffic for an hour, you should not get that hot (depending on outside air temp). You can see the left fan working and feel the air. The right fan is much louder but harder to see and feel the air due to the fact it's lower in height. You have to start first to make sure the drivers fan is coming on with the A/C.
The other side of the coin is that your thermostat could be going bad or radiator a bit cloged up. You don't run the engine to get the air out. Just remove the pressure tank cap, make sure it's full then open the small brass screws until you see the antifreeze come. Use a paper towell under screws so you dont drip on the optispark.
If you get past 240 on the road, get out of the car and look at the right side cooling fan to see if its running. (please be careful, watch your hands) Once you know this, then you can move in a logical direction.
The other side of the coin is that your thermostat could be going bad or radiator a bit cloged up. You don't run the engine to get the air out. Just remove the pressure tank cap, make sure it's full then open the small brass screws until you see the antifreeze come. Use a paper towell under screws so you dont drip on the optispark.
If you get past 240 on the road, get out of the car and look at the right side cooling fan to see if its running. (please be careful, watch your hands) Once you know this, then you can move in a logical direction.
