Signs of a failing water pump?
05-06-2006, 10:03 PM
#1
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Signs of a failing water pump?
My 1992 consistently stays above 200 and won't drop below it. I've had the coolant changed, the radiator checked, the thermostat is fine, and the converters inspected. Would a failing water pump cause overheating like this? What are some of the signs of a failing water pump?
05-06-2006, 10:07 PM
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St. Jude Donor '04-'05-'06-'07
Generally a failing water pump will leak, rare are any other symtoms although it is possible. Actually that's within the realm of normal for the LT1s temperature-wise, so don't be alarmed. I would however check for debris in the air intake area in the front of the car. These cars are like a Hoover when it comes to picking up road debris. 
05-06-2006, 10:12 PM
#4
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Originally Posted by Corvette Kid NC
Generally a failing water pump will leak, rare are any other symtoms although it is possible. Actually that's within the realm of normal for the LT1s temperature-wise, so don't be alarmed. I would however check for debris in the air intake area in the front of the car. These cars are like a Hoover when it comes to picking up road debris.
Several years ago the vette would normally range from 165-185 depending on the temperature. About 4 years ago is started this problem of overheating and hasn't been fixed. The only way to keep the car cool is to either driver above 45mph with the air off or to turn on the AC if I was going slower than 45. Could it possibly be one of the fans?
05-06-2006, 10:26 PM
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St. Jude Donor '04-'05-'06-'07
Originally Posted by Lord Odin
I've checked the air filter and air intake for anything and they are pretty clean. I've even cleaned the K&N for good measure.
Several years ago the vette would normally range from 165-185 depending on the temperature. About 4 years ago is started this problem of overheating and hasn't been fixed. The only way to keep the car cool is to either driver above 45mph with the air off or to turn on the AC if I was going slower than 45. Could it possibly be one of the fans?
Several years ago the vette would normally range from 165-185 depending on the temperature. About 4 years ago is started this problem of overheating and hasn't been fixed. The only way to keep the car cool is to either driver above 45mph with the air off or to turn on the AC if I was going slower than 45. Could it possibly be one of the fans?
05-06-2006, 10:33 PM
#8
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Originally Posted by Corvette Kid NC
Have you checked between the A/C condensor and the radiator? I'd have been more concerned when it was running between 165-185, that is not right. For maximum efficiency, shoot for 195-205.
I almost forgot, I have a 160 thermostat and a Corsa catback exhaust. Not sure if that would affect the normal operating temps or not.
05-06-2006, 11:00 PM
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St. Jude Donor '04-'05-'06-'07
Originally Posted by Lord Odin
I've looked a couple of times. Once or twice I'll find a plastic bag in there but most of the time its free and clear. Oh yeah, about 3 years ago, I had all the coolant hoses replaced because I had a blowout, too.
I almost forgot, I have a 160 thermostat and a Corsa catback exhaust. Not sure if that would affect the normal operating temps or not.
I almost forgot, I have a 160 thermostat and a Corsa catback exhaust. Not sure if that would affect the normal operating temps or not.
05-06-2006, 11:07 PM
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Originally Posted by Lord Odin
My 1992 consistently stays above 200 and won't drop below it. I've had the coolant changed, the radiator checked, the thermostat is fine, and the converters inspected. Would a failing water pump cause overheating like this? What are some of the signs of a failing water pump?
05-07-2006, 11:37 AM
#11
Le Mans Master
Your 92 sounds fine and is in line with my 94. I was running the same temperatures with the original radiator. Changed the radiator and thermostat (180) 1.5 years ago. The radiator that came out was 7/8 inch thick. The new GM repacement was 1 1/4 inch thick. This made the difference and got me below the 200 mark in Florida. Run 193 when moving and below 210 in moderate traffic. The radiator is the most direct effect on cooling when every thing is normal. Bigger the radiator better the cooling and I think the radiators are under rated from the factory (my opinion). There is lots of room for a bigger radiator if you want to pay for it.
The water pump might leak but will not effect the cooling, the impella blades are metal so they dont ware down. If it leaks replace it other wise stay with the thermostat and radiator to effect cooling if defective.
The water pump might leak but will not effect the cooling, the impella blades are metal so they dont ware down. If it leaks replace it other wise stay with the thermostat and radiator to effect cooling if defective.
05-07-2006, 02:32 PM
#12
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Looks like I'm worrying over nothing then.
There is one thing that bothers me though. About 5-6 years ago, I switched the thermostat to 160. The temps were normally like 100+ the outside temp. For example, if it were 73 out, my car would be running at 173. It wouldn't get below 165 though. By the sounds of it, my car is running fine now but that raises a new question. Why would my car operate at those temps? Was something wrong with it at the time?
There is one thing that bothers me though. About 5-6 years ago, I switched the thermostat to 160. The temps were normally like 100+ the outside temp. For example, if it were 73 out, my car would be running at 173. It wouldn't get below 165 though. By the sounds of it, my car is running fine now but that raises a new question. Why would my car operate at those temps? Was something wrong with it at the time?
05-07-2006, 08:52 PM
#13
Le Mans Master
The correct thermostat is a 180. This enables the engine to come up to operating temp quicker and operate in the design parameters. Once a thermostst opens, there all the same then and what governs the temp is the cooling system, radiator etc and outside air temp. Also the emissions stuff needs the higher temp to operate properly. If I ran a 160 in my car I would should see the same temps but getting up there slower. The 180 is recommended and thats what I go with. 
05-08-2006, 08:46 AM
#14
Le Mans Master
I have a 160* 'stat in my '94 LT1. I've had the ECM flashed to kick the cooling fans on at 190*F / off at 180*F (primary fan), and on at 195*F / off at 185*F (secondary fan). Aside from this, the car is all stock, except for a K&N filter and B&B Triflow exhaust.
With ambient temps below 80*F, my car runs ~171 - 173*F on the open road, and never goes above 190*F at idle. On the hottest of days, it'll sometimes touch the low 220s if it's allowed to idle for a long time with the A/C on (like in a parade, etc), but I think that's an indication that my radiator is not in ideal shape.
Many folks here feel that the low-170s is too cool for an LTx engine to run, but I'm happy with it.
As others have noted here, C4s are bottom-feeders and they will suck an amazing assortment of stuff off of the road. Check for and remove any debris from the front of the radiator/condenser.
As others have also noted, you should also bleed the cooling system to remove any trapped air.
Finally, don't discount the possibility that your thermostat isn't functioning optimally. The 'stat on an LTx engine not only regulates the flow of coolant through the radiator, it also regulates the bypass (recirculation) flow of coolant through the block. If the 'stat isn't opening fully, you'll get less flow through the radiator, and you'll also have some amount of hot coolant cycling back directly into the heads, rather than going through the radiator first. (Always make sure that a 'stat you install into an LTx engine is the correct dual-function 'stat, as it is NOT the same as the first-generation Small Block Chevy 'stat).
Be well,
SJW
With ambient temps below 80*F, my car runs ~171 - 173*F on the open road, and never goes above 190*F at idle. On the hottest of days, it'll sometimes touch the low 220s if it's allowed to idle for a long time with the A/C on (like in a parade, etc), but I think that's an indication that my radiator is not in ideal shape.
Many folks here feel that the low-170s is too cool for an LTx engine to run, but I'm happy with it.
As others have noted here, C4s are bottom-feeders and they will suck an amazing assortment of stuff off of the road. Check for and remove any debris from the front of the radiator/condenser.
As others have also noted, you should also bleed the cooling system to remove any trapped air.
Finally, don't discount the possibility that your thermostat isn't functioning optimally. The 'stat on an LTx engine not only regulates the flow of coolant through the radiator, it also regulates the bypass (recirculation) flow of coolant through the block. If the 'stat isn't opening fully, you'll get less flow through the radiator, and you'll also have some amount of hot coolant cycling back directly into the heads, rather than going through the radiator first. (Always make sure that a 'stat you install into an LTx engine is the correct dual-function 'stat, as it is NOT the same as the first-generation Small Block Chevy 'stat).
Be well,
SJW
Last edited by SJW; 05-08-2006 at 08:49 AM.
