C4 Overheating
Thread Starter
Instructor
Joined: Mar 2013
Posts: 248
Likes: 8
From: Dayton NV
C4 Overheating
First off I apologize if I posted this in the wrong thread.
Issue: 1992 Base Model Vet (LT1 Engine) Overheating when at idle or slow city driving.
I read all of the threads, I cleaned the radiator off, I flushed the fluid, then I realized my fans weren't coming on, even when the car was up to 215 degrees.
I pulled the plug for the fans at the relay, jumped them and they work.
I read that the fans come on when signaled to because of temperature and when you turn the AC on.
When I turn the AC on the fans come one, but not when the car gets hot.
So I let the car temp creep up to 210, while idling, then turn the ac on, and it cools back down to the 190's.
Is my solution to just turn the AC on when the car gets hot?
Suggestions? Thanks for any help!
Issue: 1992 Base Model Vet (LT1 Engine) Overheating when at idle or slow city driving.
I read all of the threads, I cleaned the radiator off, I flushed the fluid, then I realized my fans weren't coming on, even when the car was up to 215 degrees.
I pulled the plug for the fans at the relay, jumped them and they work.
I read that the fans come on when signaled to because of temperature and when you turn the AC on.
When I turn the AC on the fans come one, but not when the car gets hot.
So I let the car temp creep up to 210, while idling, then turn the ac on, and it cools back down to the 190's.
Is my solution to just turn the AC on when the car gets hot?
Suggestions? Thanks for any help!
Pro
Joined: Oct 2010
Posts: 603
Likes: 45
From: Baltimore County MD
First off I apologize if I posted this in the wrong thread.
Issue: 1992 Base Model Vet (LT1 Engine) Overheating when at idle or slow city driving.
I read all of the threads, I cleaned the radiator off, I flushed the fluid, then I realized my fans weren't coming on, even when the car was up to 215 degrees.
I pulled the plug for the fans at the relay, jumped them and they work.
I read that the fans come on when signaled to because of temperature and when you turn the AC on.
When I turn the AC on the fans come one, but not when the car gets hot.
So I let the car temp creep up to 210, while idling, then turn the ac on, and it cools back down to the 190's.
Is my solution to just turn the AC on when the car gets hot?
Suggestions? Thanks for any help!
Issue: 1992 Base Model Vet (LT1 Engine) Overheating when at idle or slow city driving.
I read all of the threads, I cleaned the radiator off, I flushed the fluid, then I realized my fans weren't coming on, even when the car was up to 215 degrees.
I pulled the plug for the fans at the relay, jumped them and they work.
I read that the fans come on when signaled to because of temperature and when you turn the AC on.
When I turn the AC on the fans come one, but not when the car gets hot.
So I let the car temp creep up to 210, while idling, then turn the ac on, and it cools back down to the 190's.
Is my solution to just turn the AC on when the car gets hot?
Suggestions? Thanks for any help!
Thread Starter
Instructor
Joined: Mar 2013
Posts: 248
Likes: 8
From: Dayton NV
Yes, as crazy as it sounds turn on the a/c. I also believe the fans come on closer to 230-235 not 215. Their is probably nothing wrong with your car. Sidebar here and beware --when you open up the system you take a chance of causing an air pocket(s) which will cause overheating. Some years have bleeder valves to remedy this. From what your saying it sounds like you do not have this problem.
Mine is equipped with a bleeder valve in the thermostat housing, and I used that to clear the air when I flushed the radiator.
Thanks for all the help!
Race Director
Joined: Dec 2000
Posts: 17,551
Likes: 26
From: El Paso Texas
C4's are designed to run hot. 225-230 in traffic isn't uncommon and won't hurt anything.
First thing you need to do on ANY C4 when you buy it is remove the radiator and clean the front of it. C4's are bottom feeders AKA road vacuums....you'll be amazed at what's on the front of it. 50% + blockage is common if it hasn't been cleaned in a while.
To answer your next question, yes, you MUST remove the radiator.....No, you cannot clean it in the car. It's not a big deal, just do it. Takes about 15 minutes to pull it out.
So pull it out, sit down with a bucket of soapy water and a nylon brush, straighten any bent fins, and clean off all the debris. Flush it off good, put it back in the car, and be amazed as it now runs 20 + degrees cooler.
Here's what it could look like...
First thing you need to do on ANY C4 when you buy it is remove the radiator and clean the front of it. C4's are bottom feeders AKA road vacuums....you'll be amazed at what's on the front of it. 50% + blockage is common if it hasn't been cleaned in a while.
To answer your next question, yes, you MUST remove the radiator.....No, you cannot clean it in the car. It's not a big deal, just do it. Takes about 15 minutes to pull it out.
So pull it out, sit down with a bucket of soapy water and a nylon brush, straighten any bent fins, and clean off all the debris. Flush it off good, put it back in the car, and be amazed as it now runs 20 + degrees cooler.
Here's what it could look like...
Last edited by Frizlefrak; Oct 24, 2014 at 02:38 PM.
Melting Slicks
Joined: Aug 2008
Posts: 2,082
Likes: 50
From: Palmdale CA
under normal conditions, you should not see temps above 235°f even idling around town on a hot day with the top off you probably won't see temps above 230° Kick on the A/C and those temps will drop to 190-215°
If your cooling system is "Tight" it will self bleed any trapped air out.
Thread Starter
Instructor
Joined: Mar 2013
Posts: 248
Likes: 8
From: Dayton NV
Thanks for the help.
Frizzle I did clean the radiator, however I didn't pull it out. I was able to get a good look at it through the passenger side of the shroud, and it was a bit dirty, but I blew it out with some compressed air, and it looked good. 15 minutes for you to pull it out, but for a newbie like me, try an hour
(at least).
Ok, so I was freaking out at 230 (because the temp gauge pings up close to the warning area), but it sounds like 230 is a normal operating temperature and I shouldn't be concerned unless it gets up there in the 250's.
Thanks all.
Frizzle I did clean the radiator, however I didn't pull it out. I was able to get a good look at it through the passenger side of the shroud, and it was a bit dirty, but I blew it out with some compressed air, and it looked good. 15 minutes for you to pull it out, but for a newbie like me, try an hour
(at least).Ok, so I was freaking out at 230 (because the temp gauge pings up close to the warning area), but it sounds like 230 is a normal operating temperature and I shouldn't be concerned unless it gets up there in the 250's.
Thanks all.
Advanced
Joined: Aug 2013
Posts: 69
Likes: 0
Thanks for the help.
Frizzle I did clean the radiator, however I didn't pull it out. I was able to get a good look at it through the passenger side of the shroud, and it was a bit dirty, but I blew it out with some compressed air, and it looked good. 15 minutes for you to pull it out, but for a newbie like me, try an hour (at least).
Ok, so I was freaking out at 230 (because the temp gauge pings up close to the warning area), but it sounds like 230 is a normal operating temperature and I shouldn't be concerned unless it gets up there in the 250's.
Thanks all.
Frizzle I did clean the radiator, however I didn't pull it out. I was able to get a good look at it through the passenger side of the shroud, and it was a bit dirty, but I blew it out with some compressed air, and it looked good. 15 minutes for you to pull it out, but for a newbie like me, try an hour
(at least).Ok, so I was freaking out at 230 (because the temp gauge pings up close to the warning area), but it sounds like 230 is a normal operating temperature and I shouldn't be concerned unless it gets up there in the 250's.
Thanks all.
Even if the whole front of the radiator was caked with dirt, I can't see why that would have any effect on the fans kicking on. I could be wrong, but that would only effect the fan's ability to actual cool the radiator.
Pro
Joined: Oct 2010
Posts: 603
Likes: 45
From: Baltimore County MD
First off I apologize if I posted this in the wrong thread.
Issue: 1992 Base Model Vet (LT1 Engine) Overheating when at idle or slow city driving.
I read all of the threads, I cleaned the radiator off, I flushed the fluid, then I realized my fans weren't coming on, even when the car was up to 215 degrees.
I pulled the plug for the fans at the relay, jumped them and they work.
I read that the fans come on when signaled to because of temperature and when you turn the AC on.
When I turn the AC on the fans come one, but not when the car gets hot.
So I let the car temp creep up to 210, while idling, then turn the ac on, and it cools back down to the 190's.
Is my solution to just turn the AC on when the car gets hot?
Suggestions? Thanks for any help!
Issue: 1992 Base Model Vet (LT1 Engine) Overheating when at idle or slow city driving.
I read all of the threads, I cleaned the radiator off, I flushed the fluid, then I realized my fans weren't coming on, even when the car was up to 215 degrees.
I pulled the plug for the fans at the relay, jumped them and they work.
I read that the fans come on when signaled to because of temperature and when you turn the AC on.
When I turn the AC on the fans come one, but not when the car gets hot.
So I let the car temp creep up to 210, while idling, then turn the ac on, and it cools back down to the 190's.
Is my solution to just turn the AC on when the car gets hot?
Suggestions? Thanks for any help!
It's a personal decision but I hit the a/c at 220 ---I do not like the engine getting hot and don't want to wait until 235 to find out I have a problem. I am in an area with a lot of heavy traffic. Their are ways to get the fans to come on sooner but I don't want spliced wires and don't have a way to reprogram the ECM so I just go low tech and hit the a/c.
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Le Mans Master
Joined: Jan 2000
Posts: 6,374
Likes: 21
From: Traverse City MI
The LT1 is designed to run hotter, I think the fans kick on at 230F without the air on. It shouldn't run much hotter then that sitting in traffic on a hot summer day.
If the radiator is clean and the system is staying at or below 230, you are fine. If you start messing with the programming or adjusting the cooling system to make it run cooler - you end up hurting performance and emissions.
If the radiator is clean and the system is staying at or below 230, you are fine. If you start messing with the programming or adjusting the cooling system to make it run cooler - you end up hurting performance and emissions.
Le Mans Master
Joined: Dec 2006
Posts: 5,139
Likes: 482
From: H-Town Texas
The LT1 is designed to run hotter, I think the fans kick on at 230F without the air on. It shouldn't run much hotter then that sitting in traffic on a hot summer day.
If the radiator is clean and the system is staying at or below 230, you are fine. If you start messing with the programming or adjusting the cooling system to make it run cooler - you end up hurting performance and emissions.
If the radiator is clean and the system is staying at or below 230, you are fine. If you start messing with the programming or adjusting the cooling system to make it run cooler - you end up hurting performance and emissions.
4th Gear
Joined: Oct 2014
Posts: 4
Likes: 0
If 230 is normal operating temp why is gauge almost pegged out, just wondering.
Race Director
Joined: Dec 2000
Posts: 17,551
Likes: 26
From: El Paso Texas
Race Director
Joined: Dec 2000
Posts: 17,551
Likes: 26
From: El Paso Texas
and it's still blocking airflow.Trust me, even if you're a novice, 30 minutes tops to get it out and give it a proper cleaning. Both my 84 and my 95 ran in heavy traffic at about 210 in 105 degree ambient temps and seldom got any hotter. They ran at 190 on the highway. I gave the radiator a cleaning that would make a drill sergeant proud....
Team Owner
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From: Riverside County Southern California
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Race Director
Joined: Dec 2000
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From: El Paso Texas
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Unless the needle is actually into the "shaded" area, the car isn't overheating.
That analog gauge has caused more issues with new owners than any other part of the car.
