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Cooling system question

Jessica19699

Well-known member
Joined
Nov 3, 2014
Messages
152
Location
Stephens City Va
Corvette
1998 Jet black coupe
Hello CAC friends I have a question not sure if it is an issue or not but last week my low coolant light came on in my car so I added coolant to the correct fill mark the light went away, I drove the car yesterday to work and while driving home the temp gauge went to the 3/4 mark on the gauge (it was pretty hot out yesterday also )now I been told and seen that corvettes run hot but this seemed a little to high for me on the guage after I got on the highway it backed down to the half mark where it normally sits (but that as after I was driving literally 75/80 mph to), after getting home I popped the hood and heard a gurgling noise comeing from under the radiator cap I didn't smell anything like antifreeze or anything I checked the overflow reservoir and it was just about dry, a friend of mine here at work that owns a vette said It sounds like the water pump might have a slight leak or I should start with that anyway, is there anyone out there that might know what this might be (if this is even an issue at all) or does it sound like the water pump to you or maybe bad thermostat. I asked my friend if it could be a blown head gasket he told me to check the oil to see if it is milky which I haven't done yet, any ideas would be greatly appreciated, thanks in advance
 
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What *F is 3/4 on your temp gauge? Verify with the engine cold where your coolant level is in both the radiator and surge tank or overflow bottle.
 
What *F is 3/4 on your temp gauge? Verify with the engine cold where your coolant level is in both the radiator and surge tank or overflow bottle.

Hi LLC I'm not sure the F on that I didn't look I guess I should have, I will look when I get home today on engine coolant level for it being cold now, yesterday when it was that hot the reservoir was pretty empty and I seen the gauge on the dip stick Is higher for hot than the cold mark I didn't check the radiator it was to hot should I pop the cap off and look? I will let you know what I find out
 
This might not be the solution but when was the last time the cooling system was flushed .When was the last time the back side of the radiator exterior was cleaned .I always vacuumed and brushed the radiator once a year .Amazing the leaves ,twigs and baby pampers get trapped up there.
 
This might not be the solution but when was the last time the cooling system was flushed .When was the last time the back side of the radiator exterior was cleaned .I always vacuumed and brushed the radiator once a year .Amazing the leaves ,twigs and baby pampers get trapped up there.

It has actually been awhile for that I will check these things thanks for the info.
 
What *F is 3/4 on your temp gauge? Verify with the engine cold where your coolant level is in both the radiator and surge tank or overflow bottle.

So i checked the a/c front grill by the radiator and there was no blockage of leaves ect, the over flow reservoir tank was just about empty so I refilled it to the cold mark on the dip stick I did pop the radiator cap and I could see antifreeze while I was looking in it I did top it off and it did take a good bit to fill it to the top about a good 1/4 of a half gallon jug I would say, I checked the oil and it other than needed a oil change it didn't look cloudy I just need to get It changed ,so im not sure what this means with it being low on coolant I had the car for about 5 years now I never had to add coolant until now the car sits a lot without being driven is it possible that the coolant can evaporate from sitting so long or could it be the water pump? I guess I will see how it runs now that I topped it off, maybe I should get a pressure test on it any other ideas is appreciated
 
Pressure checking is a good idea, also look carefully for coolant stains around the engine area and all the hoses including the heater hoses that go the firewall. Check the weep hole on the water pump with a good flashlight and articulating mirror. Look for any coolant dripping onto the ground. If any residue is seen, follow it to it's highest point.
 
Pressure checking is a good idea, also look carefully for coolant stains around the engine area and all the hoses including the heater hoses that go the firewall. Check the weep hole on the water pump with a good flashlight and articulating mirror. Look for any coolant dripping onto the ground. If any residue is seen, follow it to it's highest point.

LLC that is what my friend here suggested as well I will get the pressure test a do the other things as well, are corvettes known for blowing heads?
 
They are not known for it, but obviously it can happen. Start with a very serious/thorough visual with a strong beam flashlight, then a pressure test and go from there.
 
L FWIW, I never use a hand held pump tester, I want real world hot hoses and coolant flow. I fill the radiator full when it is cold, then fill the surge tank or reservoir (two entirely different systems) to the cold mark and run the engine to 220-230*F and check for leaks with the engine running. Shutting off the engine for safety reasons is ok, but leave it running if safely possible.
 
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They are not known for it, but obviously it can happen. Start with a very serious/thorough visual with a strong beam flashlight, then a pressure test and go from there.


LLC thanks I got a good mechanic friend that will do the pressure test, how hard is it to replace the water pump or heater core on corvettes and what is an average cost If known?
 
Heater cores are usually a big job, water pumps not too bad.
 
LLC thanks I got a good mechanic friend that will do the pressure test, how hard is it to replace the water pump or heater core on corvettes and what is an average cost If known?

I replaced the heater core in an 89 I had and was told before I did it that there's a reason it's labeled as Part # 000001. Not a fun job..
 
Heater cores are usually a big job, water pumps not too bad.

if the heater core is bad will the heater still work? what are some other signs that the heater core could be bad, a friend told me to feel the carpet on the passenger side floor to see if it is wet I also heard about fogging windshield any truth to this?
 
if the heater core is bad will the heater still work? what are some other signs that the heater core could be bad, a friend told me to feel the carpet on the passenger side floor to see if it is wet I also heard about fogging windshield any truth to this?



The heater can work ok until the coolant level gets low enough to not fill the heater core, both damp carpets and oily residue on the windshield can happen. If it’s bad enough you can smell the coolant in the cabin also.
 
The heater can work ok until the coolant level gets low enough to not fill the heater core, both damp carpets and oily residue on the windshield can happen. If it’s bad enough you can smell the coolant in the cabin also.

LLC So I had the car pressure tested today and it turns out the water pump is bad he told me he can get a pump for 230.00 I told him I found one for cheaper he told me he would price match me with my price so with labor and the price I told him I can get one for it will cost me around 350.00, so thank god it was the easier of the fixes thanks for all your help and replies that did one.
 

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