Help overheating on a 84
Thread Starter
Instructor
Joined: Aug 2003
Posts: 204
Likes: 0
From: GALES FERRY CT
Help overheating on a 84
My 84 is just starting to overheat. It used to run a temp of around 195 then one day I was driving and the temp started to rise. I thought I had a bad thermostat so I changed it with a 180deg one. Water level was good and no leaks. Air flow in the front was not blocked. The temp came down at first to 210-225. Then it started to rise again and went to over 255. I stopped the car let it cool and tried again temp would rise to 225 then go down and then rise but not overheat , top hose was hot but you could squeeze it. Shut the car off tried again temp rose to overheat and the top hose was hot and you could not squeeze it. Need help!!!! 
Melting Slicks
Joined: Jan 2005
Posts: 2,658
Likes: 4
From: Clifton Park NY
Don't assume you have a head gasket problem until you check some other common problems out first.
Have you checked for debris between the condensor and the radiator? very common problem
At what temp is your fan turning on?
Remember don't just throw parts at it. Troubleshoot first
When I first got mine it used to climb up to 240 in traffic. Now the car never or should I say hardly ever sees over 205.
Thread Starter
Instructor
Joined: Aug 2003
Posts: 204
Likes: 0
From: GALES FERRY CT
Fan is turning at at 190. Yesterday I took it around the block about 2 miles. The temp climbed to 259 just as I ended, I pulled in the drive and then sat at idle and the temp came down to 214. So I am really lost now.
Race Director
Joined: Sep 2000
Posts: 17,298
Likes: 33
From: The Top of Utah
Originally Posted by MILESTONE#001
Fan is turning at at 190. Yesterday I took it around the block about 2 miles. The temp climbed to 259 just as I ended, I pulled in the drive and then sat at idle and the temp came down to 214. So I am really lost now.
If you didn't pull the radiator, chances are your the "Air flow in the front was not blocked." comment may not be accurate. As qws suggests you likely DO have an air flow problem caused by a blockage not casually detected. The sucking up of a plastic bag or other debris can easily cause a "sudden" problem. Unless you have done it before and know what to look for, pull the radiator and clean out from in between the radiator and condenser. You might be surprised what you find in there.
Additionally, fully warmed up, the hose should be hard. If you can easily squeeze the hose, you may have air in the system, or a radiator cap that won't hold pressure.
RACE ON!!!
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Le Mans Master
Joined: Oct 2003
Posts: 6,130
Likes: 2
From: seattle WA
You replaced the thermostat, perhaps it was bad. Burping the system is removing air pockets. Put the car on a slight incline (front up), take the radiator cap off and run the engine, at around 1500 RPMs (at operating temps) watch the coolant level in the radiator, as it drops (forcing the air out of the system) add coolant.
Race Director
Joined: Sep 2000
Posts: 17,298
Likes: 33
From: The Top of Utah
Originally Posted by MILESTONE#001
The radiator is only about 2 years old was put in new at the local dealer. and the fan is electric.
All C4s have electric fans. If it weren't electric it couldn't be coming on too early. A mechanical, belt driven, fan is always turning, although the fan clutch might not be engaged. A fan on temp of 190° is too low, especially in an engine that frequently runs at 195°.
RACE ON!!!
Melting Slicks
Joined: Feb 2008
Posts: 3,286
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From: Palm Beach
Drifting
Joined: Aug 2003
Posts: 1,565
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From: somewhere between heaven and hell WI
I have not pulled the radiator in my 84 in a long time, but see if there is mounts on the top that you can remove and tilt the radiator toward the engine. You should be able to see in between the radiator and condensor for any debris.
I think there is a large plastic shroud over the radiator. Try removing that to see in there.
I think there is a large plastic shroud over the radiator. Try removing that to see in there.
Le Mans Master
Joined: Oct 2003
Posts: 6,130
Likes: 2
From: seattle WA
I just pulled the shroud on my 87 when I cleaned mine, and it was packed in between with all kinds of debris. I used a very narrow attachment on my shop vac. and then hosed it out. Just becareful not to damage the radiator or condensor.
