[C1] Overheating Issue
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From: Mooresville NC
Overheating Issue
Hello All,
Can I ask what your cars average in terms of engine temp under normal city driving?
My car usually runs right at the 180 degree mark with occasional bumps up to 190 or so, and then back down to 180/185.
Lately, it's been spiking up to the 200/215 degree range when waiting at traffic lights.
Granted, the weather here has been in the low to mid 90's in the last few days, and I'm sure that may have something to do with it.
But I would still expect to see a stable temp (even if it's a little higher), if everything was working as it should be.
My feeling is that there is something wrong when I see wide swings in temperature.
The coolant level in the Overflow Tank is roughly 3/4 full when the engine is cool. There are no coolant leaks below the car.
The radiator appears to be fairly new, and in very good condition.
What has been your experience?
Is this just some thing that we have to deal with with these classic cars? Or is there a reason to stay ahead of it and try to find and resolve the issue?
Thank you,
Mike
Can I ask what your cars average in terms of engine temp under normal city driving?
My car usually runs right at the 180 degree mark with occasional bumps up to 190 or so, and then back down to 180/185.
Lately, it's been spiking up to the 200/215 degree range when waiting at traffic lights.
Granted, the weather here has been in the low to mid 90's in the last few days, and I'm sure that may have something to do with it.
But I would still expect to see a stable temp (even if it's a little higher), if everything was working as it should be.
My feeling is that there is something wrong when I see wide swings in temperature.
The coolant level in the Overflow Tank is roughly 3/4 full when the engine is cool. There are no coolant leaks below the car.
The radiator appears to be fairly new, and in very good condition.
What has been your experience?
Is this just some thing that we have to deal with with these classic cars? Or is there a reason to stay ahead of it and try to find and resolve the issue?
Thank you,
Mike
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My 59 was doing the same thing this spring. Had to add about half a quart of coolant and it’s normal again. Don’t know why I have to periodically add coolant, no leaks?
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Dan
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From: Mooresville NC
Thank you both.
I don't mind it getting up to around 200 but when it gets to 215/220 and would keep climbing, it makes me nervous.
It seems as though the water pump is not moving enough coolant through the engine as it's sitting idle. And when I start moving, the air flow through the radiator seems to be compensating to get the temp back down.
I'll just watch it for a couple of weeks to see if it continues. If I keep seeing it, I might go ahead and change the pump.
Thanks again.
Mike
I don't mind it getting up to around 200 but when it gets to 215/220 and would keep climbing, it makes me nervous.
It seems as though the water pump is not moving enough coolant through the engine as it's sitting idle. And when I start moving, the air flow through the radiator seems to be compensating to get the temp back down.
I'll just watch it for a couple of weeks to see if it continues. If I keep seeing it, I might go ahead and change the pump.
Thanks again.
Mike
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Mike, overheating problems that present themselves in traffic at idle are almost always air flow issues and hardly ever coolant flow issues. Doesn't mean it can't be a collapsed hose or a clogged radiator. But if she runs fine on the road and gets up to 215 or 220 on a 90-degree day stuck in traffic that would not concern me.
As to the habitual burping of coolant from radiator overflow, this is almost always caused by an owner not recognizing that coolant level has to reach equilibrium. When you overfill inadvertently, coolant expands and the extra volume gets burped out. if you fall into the trap of continuing to overfill it every time it burps thinking it's necessary just creates a circular problem. Fill it to the proper level and leave it alone it might burp a few times it might not. Just let it be and it will find its natural level
Dan
As to the habitual burping of coolant from radiator overflow, this is almost always caused by an owner not recognizing that coolant level has to reach equilibrium. When you overfill inadvertently, coolant expands and the extra volume gets burped out. if you fall into the trap of continuing to overfill it every time it burps thinking it's necessary just creates a circular problem. Fill it to the proper level and leave it alone it might burp a few times it might not. Just let it be and it will find its natural level
Dan
Last edited by dplotkin; May 27, 2019 at 09:46 AM.
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From: Mooresville NC
Mike, overheating problems that present themselves in traffic at idle are almost always air flow issues and hardly ever coolant flow issues. Doesn't mean it can't be a collapsed hose or a clogged radiator. But if she runs fine on the road and gets up to 215 or 220 on a 90-degree day stuck in traffic that would not concern me.
As to the habitual burping of coolant from radiator overflow, this is almost always caused by an owner not recognizing that coolant level has to reach equilibrium. When you overfill inadvertently, coolant expands and the extra volume gets burped out. if you fall into the trap of continuing to overfill it every time it burps thinking it's necessary just creates a circular problem. Fill it to the proper level and leave it alone it might burp a few times it might not. Just let it be and it will find its natural level
Dan
As to the habitual burping of coolant from radiator overflow, this is almost always caused by an owner not recognizing that coolant level has to reach equilibrium. When you overfill inadvertently, coolant expands and the extra volume gets burped out. if you fall into the trap of continuing to overfill it every time it burps thinking it's necessary just creates a circular problem. Fill it to the proper level and leave it alone it might burp a few times it might not. Just let it be and it will find its natural level
Dan
I am new to the Classics world, but doing my best to learn the "craft". I didn't realize how much I would enjoy this car, it's quirks of maintenance, and it's history.
Mike
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Best advice is to get a copy of the shop manual and read it, all of it. That will teach you how your car is put together, how it works, and what is likely wrong when you have trouble. Even if you rely on others to wrench on your car reading the manual will be helpful to you in understanding an issue, or in your case, a likely non-issue.
The old car hobby necessarily involves maintenance, malfunction and running problems as did the TV sets from the same era.
On the other hand that these relics still crawl the streets is testament enough to their longevity and toughness. Plug and play they are not, they need hands on and love, and give back twice that in fun.
You will love your car and the hobby. Have fun and be safe!
Dan
Last edited by dplotkin; May 27, 2019 at 10:44 AM.
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Does it look like you ahve factory GM water pump? Those pump fine at idle. Some of teh aftermarket whiz bang pumps don't pump anything at idle as they are designed to not over pump at high RPM.
Make sure the gaps between the fan shroud and the radiator are all closed.
I dropped pieces of black foam pipe insulation down the sides,and made something to seal the gap at the top. Your fan should also be half in/out of the shroud.
And just for info, mid 1960s big block Impalas, had no fan shrouds,and cooled fine, but they had an idiot light, so people wouldn't get alarmed if the temp went over 200 or so.
Doug
Make sure the gaps between the fan shroud and the radiator are all closed.
I dropped pieces of black foam pipe insulation down the sides,and made something to seal the gap at the top. Your fan should also be half in/out of the shroud.
And just for info, mid 1960s big block Impalas, had no fan shrouds,and cooled fine, but they had an idiot light, so people wouldn't get alarmed if the temp went over 200 or so.
Doug
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Double check your fan clutch to ensure it's functioning properly. As was mentioned, in high ambient temps and stop and go driving you need as much airflow over the radiator as possible to maintain the lowest operating temp. Wouldn't hurt to have the radiator cap tested as well (and, be sure you have the proper cap to begin with).
Last edited by leif.anderson93; May 27, 2019 at 11:22 AM.
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For max cooling at idle, you need to "seal" any gaps between the radiator and shroud. The air will take the path of least resistance, sometimes bypassing the radiator.
Some aftermarket radiators leave large gaps. Post a photo of your configuration..
Also, make sure your fan blades are positioned "1/2 in - 1/2 out" of the shroud"
One more thing... timing can effect the idle temp as well.... worth a check...
Fred
Some aftermarket radiators leave large gaps. Post a photo of your configuration..
Also, make sure your fan blades are positioned "1/2 in - 1/2 out" of the shroud"
One more thing... timing can effect the idle temp as well.... worth a check...
Fred
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Double check your fan clutch to ensure it's functioning properly. As was mentioned, in high ambient temps and stop and go driving you need as much airflow over the radiator as possible to maintain the lowest operating temp. Wouldn't hurt to have the radiator cap tested as well (and, be sure you have the proper cap to begin with).
It was the fan clutch. It only showed a problem when the ambient temp got to 90.
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From: Mooresville NC
The block off panels on the top of the radiator: Are these parts that can be purchased or did you fabricate them?
Also, would you please post a picture of your engine. If I rebuild my 350, I've been thinking of going to a 383.
Thank you,
Mike
Last edited by 62 C1 Owner; May 28, 2019 at 09:56 AM.
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Here’s a picture of the engine just before I sealed around the radiator. You can see how big of a gap there was.
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To the Op
The Fans are dual speed, Mine was running hot and fans were working BUT never went into dual hi speed when Hot, every thing fine idling driving it got hot.
Changed Fan relays fixed my problem dual speed works once again.
Also being bottom feeder Its possible to pick up a plastic trash bag or something else and block off radiator air flow or drastically reduce it.
The Fans are dual speed, Mine was running hot and fans were working BUT never went into dual hi speed when Hot, every thing fine idling driving it got hot.
Changed Fan relays fixed my problem dual speed works once again.
Also being bottom feeder Its possible to pick up a plastic trash bag or something else and block off radiator air flow or drastically reduce it.
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If you want to do a real quick check of your clutch fan PLEASE do this, after getting engine up to operating temps 190 or so so stat should be fully open, with engine running open hood reach in window to get ready to shut engine off while you are watching your radiator fan spin shut engine off & observe rad fan it should stop immediately with your shutting off of the engine if not time to replace that clutch fan..
Regards, Chalie
Regards, Chalie
