Overheating problem!!!!
Race Director
Joined: May 2004
Posts: 16,667
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From: Raleigh, NC
St. Jude Donor '15
Originally Posted by bayarea
why do I get the exact opposite. when I'm driving my temps climb to 220 ish then when I stop in traffic temp goes down. could this be my thermostat also?
I had the same problem on a different car and it turned out to be a radiator clogged internally. You could run water thru it and tell only about half of it was getting any liquid through it. I guess that was enough to cool it off when it was sitting still and not producing that much heat but not when cruising...
Race Director
Joined: May 2004
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From: Raleigh, NC
St. Jude Donor '15
I had to get a new one...the radiator shop I took it to cleaned it out pretty well with some high pressure stuff they had but they couldn't get it totally cleaned out
Race Director
Joined: Oct 2002
Posts: 16,477
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From: Gone
CI 6-7-8-9-10 Veteran
St. Jude Donor '03
Originally Posted by Evil-Twin
So for those "Experts" out there, When referring to looking up the air dam and cleaning the "RADIATOR", your information is wrong, and mis leading as to the root cause of high coolant and oil temps...
I suppose if that happened to you, you'd still disassemble the entire cooling system first to check each and every compnent.
Most everyone else would take a peek up there, pull out the bag, and test the car to see if that was indeed the cause of the problem.
It doesn't much matter if it's blocking the condensor first, it is also blocking the radiator. In an instance like this, looking up the cavity in front of the air dam is the easiest thing to check first. If you find something such as a plastic bag, or a bunch of large leaves stuck in there, you may have likely found the root cause of the problem.
While your technical information is all correct, small debris that accumulates over time in the radiator fins isn't always the cause of every cooling problem either, and you didn't neccesarily troubleshoot or pinpoint this particular problem. You offered one possibility. So did the people who simply suggest checking the easy and obvious things first. The "correct fix" can only be done once the root cause of the problem has been located, and since you haven't done that yet, I can't see how you can state what the correct fix is yet.
First rule in troubleshooting: Check the obvious first, then dig deeper if necessary.
Race Director
Joined: Oct 2002
Posts: 16,477
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From: Gone
CI 6-7-8-9-10 Veteran
St. Jude Donor '03
Ditty22,
You only mentioned the oil temps, which are well within the "normal" range. Oil temp is more variable depending on how you are driving the car. Although my car usually runs oil temps in the 212-220 range, I've seen oil temp as high as 245 on occasion, with coolant temps still in the normal range. Consistent higher rpm operation will drive oil temps up.
What are your coolant temps? If they are normal, your car isn't overheating.
Is your oil level full? Recently changed? Thicker weight oil?
You only mentioned the oil temps, which are well within the "normal" range. Oil temp is more variable depending on how you are driving the car. Although my car usually runs oil temps in the 212-220 range, I've seen oil temp as high as 245 on occasion, with coolant temps still in the normal range. Consistent higher rpm operation will drive oil temps up.
What are your coolant temps? If they are normal, your car isn't overheating.
Is your oil level full? Recently changed? Thicker weight oil?
2nd Gear
Joined: Jan 2005
Posts: 2
Likes: 0
From: monroe ny
You Hit the Nail on the head
Originally Posted by Evil-Twin
First of all, looking up from the air dam would reveal debris stuck in the Air conditioner condenser Not the radiator....
The Condenser and the radiator are in tandem, much debris gets caught in the obvious places at the top of the air dam duct and stuck to the condenser...
Much of this debris get sucked through the condenser fins and winds up
blocking the actual radiator. The way to clean this is to remove the upper radiator shroud which holds the condenser and radiator.
Many people remove the debris that is stuck to the AC condenser because, that's what so many ill informed people suggest, and point to it as if it was the radiator, just as in the information given here in the above thread.
The real culprit is found behind the Condenser, the actual radiator and this needs to be addressed. Cleaning the condenser will help the AC unit work more efficiently and also help to pass cool air to the radiator found behind it... but with a clogged radiator, all the cold air in the world will not help with heat exchange. So for those "Experts" out there, When referring to looking up the air dam and cleaning the "RADIATOR", your information is wrong, and mis leading as to the root cause of high coolant and oil temps...
The correct fix is to clean both the condenser and the radiator,hidden from view and found two inches behind the condenser, the true radiator... not the one all the wannabes refer too...
Every year I clean out my radiator, the one behind the condenser and get a cup of grass, sand, bug guts, leaves and paper that made it's way through the condenser fins.
This is how it should be done.
The Condenser and the radiator are in tandem, much debris gets caught in the obvious places at the top of the air dam duct and stuck to the condenser...
Much of this debris get sucked through the condenser fins and winds up
blocking the actual radiator. The way to clean this is to remove the upper radiator shroud which holds the condenser and radiator.
Many people remove the debris that is stuck to the AC condenser because, that's what so many ill informed people suggest, and point to it as if it was the radiator, just as in the information given here in the above thread.
The real culprit is found behind the Condenser, the actual radiator and this needs to be addressed. Cleaning the condenser will help the AC unit work more efficiently and also help to pass cool air to the radiator found behind it... but with a clogged radiator, all the cold air in the world will not help with heat exchange. So for those "Experts" out there, When referring to looking up the air dam and cleaning the "RADIATOR", your information is wrong, and mis leading as to the root cause of high coolant and oil temps...
The correct fix is to clean both the condenser and the radiator,hidden from view and found two inches behind the condenser, the true radiator... not the one all the wannabes refer too...
Every year I clean out my radiator, the one behind the condenser and get a cup of grass, sand, bug guts, leaves and paper that made it's way through the condenser fins.
This is how it should be done.
Hi Evil Twin you hit the nail on the head with your post.
My name is Peter Mack
This last winter I bought a 1988 corvette .Just recently with the weather warming up I noticed the car would cycle on the cooling fans even though i was moving at highway speeds .I had already changed the Thermostat and added a 180 degree fan control and have both fans coming on together .I figured maybe the radiator was shot So I started to remove it from the car.I had read on the Forum
about leaves and debris getting up in the radiator area and after inspection saw nothing obvious that could cause the problem.! Well like you said between the condenser coil and the actual radiator is this space that was filled up with leaves and debris covering over two thirds of the radiator coil surface. This is a closed area of the shroud and can't be seen without removing the upper radiator support because the bottom and top is enclosed, whatever works its way in there stays in there unless cleaned out manually (bad design).Thank you for pointing this out
Peter Mack NY
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From: Raleigh, NC
St. Jude Donor '15
Mine has been running hot lately as well...
During the winter (<50 degrees) the car was always 183 or 185 degrees (180 t-stat). Now that the weather is warming up (broke 100 today) the car is over 230 if I leave the AC on and around 230 around town even with it off, regardless of being on the highway or sitting still. The fans are coming on fine. They've been programmed to keep the car under 200, I'm not sure of the exact #'s because the previous owner had the work done; but I can hear them kicking in pretty early. I switched over to a 170 t-stat last week, no change. I took the cover off the radiator this wknd and there was no significant amount of dirt that I could see between the condensor and radiator. I sprayed the fins out (what little I could get to..) with compressed air and TONS of crap came out. I'm going to pull the radiator next weekend and take a pressure washer or something to it and the condensor. I also ordered a new air-dam because mine is pretty beat up and that can't be helping much. Hopefully I can get this thing under control... Turning the AC off with regular 90+ degree temperatures sucks!!
During the winter (<50 degrees) the car was always 183 or 185 degrees (180 t-stat). Now that the weather is warming up (broke 100 today) the car is over 230 if I leave the AC on and around 230 around town even with it off, regardless of being on the highway or sitting still. The fans are coming on fine. They've been programmed to keep the car under 200, I'm not sure of the exact #'s because the previous owner had the work done; but I can hear them kicking in pretty early. I switched over to a 170 t-stat last week, no change. I took the cover off the radiator this wknd and there was no significant amount of dirt that I could see between the condensor and radiator. I sprayed the fins out (what little I could get to..) with compressed air and TONS of crap came out. I'm going to pull the radiator next weekend and take a pressure washer or something to it and the condensor. I also ordered a new air-dam because mine is pretty beat up and that can't be helping much. Hopefully I can get this thing under control... Turning the AC off with regular 90+ degree temperatures sucks!!
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Race Director
Joined: May 2004
Posts: 16,667
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From: Raleigh, NC
St. Jude Donor '15
Tore the radiator and condensor out today... Car was getting to 230 with AC off and highway cruising. On the way home after pressure washing everything it never got over 190 with it 90+ outside and the AC on high the whole way 
Drifting
Joined: Mar 2004
Posts: 1,500
Likes: 1
From: Mauldin sc
St. Jude Donor '05
That is very clean and shows how its so important to keep good air flow going to the radiator compartment and also keep that radiator clean and protected from road trash and water contamination and that is what the Big Mouth Air Dam is all about. It will keep cold air flowing into the radiator compartment and at the same time prevent and minimize road trash and water from contaminating your radiator and A/c condenser.
