Engine coolant loss
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Joined: Jun 2015
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From: New Orleans LA
St. Jude Donor '15-'16
Engine coolant loss
I'm having engine coolant loss during track sessions. There is no obvious leak anywhere in the system, and no indication of water in the oil. I suspect a bad thermostat and resulting coolant loss out of the overflow line from the coolant reservoir. This would only show up at high temps on the track and there would be no leakage showing back in the pits, only low coolant level, which is what I have.
I can't find the overflow line from the plastic reservoir tank on the passenger side firewall. Is anyone familiar with that tank and the coolant system, and can tell me where the overflow line is located? I want to test my theory by attaching an empty bottle to the end of that line and running the engine hard. Thanks
JV
I can't find the overflow line from the plastic reservoir tank on the passenger side firewall. Is anyone familiar with that tank and the coolant system, and can tell me where the overflow line is located? I want to test my theory by attaching an empty bottle to the end of that line and running the engine hard. Thanks
JV
Last edited by Jet Vet; May 7, 2017 at 08:40 PM.
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From: Charlotte, NC (formerly Endicott, NY)
You could have a small coolant leak in the head gasket or the intake manifold. Have you checked the underside of the water pump to see if the pulley and the bottom of the pump feel sticky. My C6Z had a slight leak from the water pump that didn't show up over night. It took 24 hours before it would drop a few drops of coolant. I was literally working on the car getting for a track event and took a lunch break. When I came back to the car a half hour later there was a small puddle of coolant under the car that wasn't there before I went to lunch. That was right around 24 hours after I had parked the car in the gareage. Once the dealer replaced the water pump the sticky feeling under the pump and the back side of the pulley was gone.
Bill
Bill
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Joined: Jun 2015
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From: New Orleans LA
St. Jude Donor '15-'16
You could have a small coolant leak in the head gasket or the intake manifold. Have you checked the underside of the water pump to see if the pulley and the bottom of the pump feel sticky. My C6Z had a slight leak from the water pump that didn't show up over night. It took 24 hours before it would drop a few drops of coolant. I was literally working on the car getting for a track event and took a lunch break. When I came back to the car a half hour later there was a small puddle of coolant under the car that wasn't there before I went to lunch. That was right around 24 hours after I had parked the car in the gareage. Once the dealer replaced the water pump the sticky feeling under the pump and the back side of the pulley was gone.
Bill
Bill
JV
Tech Contributor
Joined: Oct 1999
Posts: 41,037
Likes: 9,798
From: Charlotte, NC (formerly Endicott, NY)
It could easily be pumped right out the exhaust. If you are losing that much a head gasket leak should leave a cloud of white smoke behind the car. It would tend to shorten the cat life significantly as well.
Use a cooling system pressure tester to check for pressure drops when the car is cold and when it is hot.
Bill
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Pro
Joined: Jun 2015
Posts: 696
Likes: 194
From: New Orleans LA
St. Jude Donor '15-'16
A leaky head gasket may not put coolant into the oil. We had a car that had a leak that showed up as the engine cooled and coolant would get sucked into the cylinder. One day when we went to start the engine it was hydrolocked. When I pulled the spark plugs to try and figure out why the starter couldn't crank the engine I got a large amount of coolant flowing out of one spark plug hole.
It could easily be pumped right out the exhaust. If you are losing that much a head gasket leak should leave a cloud of white smoke behind the car. It would tend to shorten the cat life significantly as well.
Use a cooling system pressure tester to check for pressure drops when the car is cold and when it is hot.
Bill
It could easily be pumped right out the exhaust. If you are losing that much a head gasket leak should leave a cloud of white smoke behind the car. It would tend to shorten the cat life significantly as well.
Use a cooling system pressure tester to check for pressure drops when the car is cold and when it is hot.
Bill
JV
