overheating problem???
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overheating problem??? Hi guys, my car is starting to have an overheating problem that I'm having trouble diagnosing. It is an ls swapped gbody monte carlo. Up until now, my car never had a problem cooling. At idle, the temp would climb up to around 205-210, my electric fans would kick on, and the temp would drop right back down. But now, at idle, the temp climbs up to 225 with no sign of stopping, and then I just shut the car off.
I have a massive 4 row copper brass radiator. The previous owners of my car had it custom made and I inherited it with the car. It previously cooled a 600 horse iron headed big block WITHOUT a fan shroud.
I have bled the system for air a few times with no avail, I have front and rear steam vents that I've opened up and bled coolant out of.
My Taurus fans are running, and I've confirmed that they are freely flowing air through the radiator.
I replaced my thermostat and it did not make a difference.
Here are a few observations I've made. *while the engine is starting to overheat* , my upper radiator hose is hot, while my lower hose is pretty cool......and, when my engine temp climbs up close to 220, if I Rev the engine to around 2500 rpm, the engine cools down very quickly to 205.....
This makes me believe that either my waterpump is on its way out, it's a relatively new ls3 water pump with just a few hundred miles on it, or my radiator is clogged up. Any advice on how I can diagnose my problem going forward?
As always, thank you!
I have a massive 4 row copper brass radiator. The previous owners of my car had it custom made and I inherited it with the car. It previously cooled a 600 horse iron headed big block WITHOUT a fan shroud.
I have bled the system for air a few times with no avail, I have front and rear steam vents that I've opened up and bled coolant out of.
My Taurus fans are running, and I've confirmed that they are freely flowing air through the radiator.
I replaced my thermostat and it did not make a difference.
Here are a few observations I've made. *while the engine is starting to overheat* , my upper radiator hose is hot, while my lower hose is pretty cool......and, when my engine temp climbs up close to 220, if I Rev the engine to around 2500 rpm, the engine cools down very quickly to 205.....
This makes me believe that either my waterpump is on its way out, it's a relatively new ls3 water pump with just a few hundred miles on it, or my radiator is clogged up. Any advice on how I can diagnose my problem going forward?
As always, thank you!
On The Tree
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Not an expert but I'd start troubleshooting cheap to expensive. Flush radiator and check for external radiator obstructions (bag, debris stuck in front) first. If that doesn't work, then I'd replace water pump.
Last edited by NineZeroFive; Jun 18, 2016 at 03:21 AM.
Water pumps never stop pumping water/coolant......unless the shaft is sheared. They spring leaks in their seals, thats why we have to replace them. But if it was sheared then you would overheat immediately, every time.
Take the t-stat out and bolt the housing back up.....see if both radiator hoses get hot. If they do, then there's no obstruction. Obstructions and clogged radiators is almost an impossible thing, unless you drop a rag into the radiator.
I would guess you purchased a bad "new" t-stat....and the old t-stat was the problem.
But first check for flow the way I described.......
.
Take the t-stat out and bolt the housing back up.....see if both radiator hoses get hot. If they do, then there's no obstruction. Obstructions and clogged radiators is almost an impossible thing, unless you drop a rag into the radiator.
I would guess you purchased a bad "new" t-stat....and the old t-stat was the problem.
But first check for flow the way I described.......
.
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The only problem with removing the thermostat is that the ls1 "thermostat" also has a contains a bypass valve, without the bypass valve in place, hot water will just circulate around in the engine
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Hey guys, this overheating problem is really starting to eat my lunch. I just replaced my old copper radiator with a new aluminum radiator ( dual 1" rows) and it is still over heating. I'm 95% sure I got all of the air bled out of the system.
Here is one observation I've made. When parked and idling, and with my heater control valve open. The temperature will maintain at 208-210. Although the fans can't cool it under that temp, it will maintain. But when I CLOSE my heater control valve, the temp will quickly climb to 220, and the fans can no longer maintain temperature. It almost seems like the heater core pulls just enough heat out of engine to maintain temp. Either that or its having some kind of affect on my thermostat bypass valve. Either way, I'm confused.
Here is one observation I've made. When parked and idling, and with my heater control valve open. The temperature will maintain at 208-210. Although the fans can't cool it under that temp, it will maintain. But when I CLOSE my heater control valve, the temp will quickly climb to 220, and the fans can no longer maintain temperature. It almost seems like the heater core pulls just enough heat out of engine to maintain temp. Either that or its having some kind of affect on my thermostat bypass valve. Either way, I'm confused.
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How much area of the radiator does the fans
cover? Is it possible they do not pull enough
air through radiator? Does the fans pull air through radiator or just all around? Does the radiator have baffles to guide air through radiator or can air go around radiator?
Just thoughts
cover? Is it possible they do not pull enough
air through radiator? Does the fans pull air through radiator or just all around? Does the radiator have baffles to guide air through radiator or can air go around radiator?
Just thoughts
Thread Starter
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How much area of the radiator does the fans
cover? Is it possible they do not pull enough
air through radiator? Does the fans pull air through radiator or just all around? Does the radiator have baffles to guide air through radiator or can air go around radiator?
Just thoughts
cover? Is it possible they do not pull enough
air through radiator? Does the fans pull air through radiator or just all around? Does the radiator have baffles to guide air through radiator or can air go around radiator?
Just thoughts
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From: So.Cal.
This is an LS engine...?
Do you have the radiator hoses connected as follows:
- hose going to TS housing is the lower rad hose.
- hose coming from water pump is upper rad hose.
- radiator flows across, from upper hose location to lower hose location.
Do you have the radiator hoses connected as follows:
- hose going to TS housing is the lower rad hose.
- hose coming from water pump is upper rad hose.
- radiator flows across, from upper hose location to lower hose location.
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hose going to TS housing is the lower rad hose. Yes
- hose coming from water pump is upper rad hose. Yes
- radiator flows across, from upper hose location to lower hose location
Yes
Thread Starter
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Have you had this problem since water pump replacement?
Is it possible the water pumps impeller is slipping on the drive shaft of pump?
Or is corroded?
I remember reading something about if you use a copper radiator with aluminum engine
you need a sacrificial anode bar, they make one that screws into the drain **** on the
bottom of radiators, thats probably not the issue, the thought just pulled up.
Is it possible the water pumps impeller is slipping on the drive shaft of pump?
Or is corroded?
I remember reading something about if you use a copper radiator with aluminum engine
you need a sacrificial anode bar, they make one that screws into the drain **** on the
bottom of radiators, thats probably not the issue, the thought just pulled up.
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From: So.Cal.
...
Here are a few observations I've made. *while the engine is starting to overheat* , my upper radiator hose is hot, while my lower hose is pretty cool......and, when my engine temp climbs up close to 220, if I Rev the engine to around 2500 rpm, the engine cools down very quickly to 205.....
...
Here are a few observations I've made. *while the engine is starting to overheat* , my upper radiator hose is hot, while my lower hose is pretty cool......and, when my engine temp climbs up close to 220, if I Rev the engine to around 2500 rpm, the engine cools down very quickly to 205.....
...
Thread Starter
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I actually just ordered a new water pump, but before I install the "new" water pump. I'm going to take the thermostat out of my old water pump, and drive a freeze plug into the bypass hole, reinstall, and just see what happens.
Thread Starter
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Joined: Jan 2007
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Have you had this problem since water pump replacement?
Is it possible the water pumps impeller is slipping on the drive shaft of pump?
Or is corroded?
I remember reading something about if you use a copper radiator with aluminum engine
you need a sacrificial anode bar, they make one that screws into the drain **** on the
bottom of radiators, thats probably not the issue, the thought just pulled up.
Is it possible the water pumps impeller is slipping on the drive shaft of pump?
Or is corroded?
I remember reading something about if you use a copper radiator with aluminum engine
you need a sacrificial anode bar, they make one that screws into the drain **** on the
bottom of radiators, thats probably not the issue, the thought just pulled up.
Thread Starter
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Update : I hooked my wide band o2 sensor up tonight, and at idle, my afr hovers around 14.7, so at least I know my engine isn't running lean.
Plus, I took some readings with an infared thermometer, and with my ect sensor reading 210, the water outlet of my water pump was only reading around 160, and the low pressure side of my radiator reads around 130.
So my gauge may possibly be bad, or water isn't getting circulated out of my engine.
Plus at least. I know my radiator is working
Plus, I took some readings with an infared thermometer, and with my ect sensor reading 210, the water outlet of my water pump was only reading around 160, and the low pressure side of my radiator reads around 130.
So my gauge may possibly be bad, or water isn't getting circulated out of my engine.
Plus at least. I know my radiator is working
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I got it! I replaced my water pump last night, and it seems like my cooling system is back to working like normal. I know water pump failures are very rare, but I think I know what happened. Shorty before I started having this problem, a bunch of old crusty sediment from my overflow bottle got swept into my cooling system. The only thing that I can figure is that sediment clogged or beat up my water pump impeller. So I'm going to look into installing a temporary coolant filter to try and catch the rest on the sediment that's in there.
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