Coolant Issue ?
Thread Starter
Drifting
Joined: Nov 2018
Posts: 1,800
Likes: 579
From: Mays Landing, NJ
Coolant Issue ?
Had my 95 out today running some errands and saw the temp start going up and a minute later the "Low Coolant" light came on. Turned the A/C in case the fan(s) weren't coming on and being close to home I was able to make it with the temps in the low 240's. Sure enough, got under the hood and find the overflow tank fuller then normal and removing the cap showed that the tank was low. It took just over 3/4 gallon of premix I had. Took it on a test ride and temps stayed normal.
Checked the upper and lower hoses for leakage in addition to cap and found no issues. I don't think it is a head casket issue because exhaust smells and looks fine. Maybe there is such a small leak I never noticed it was getting low. Any thoughts from the community.
Checked the upper and lower hoses for leakage in addition to cap and found no issues. I don't think it is a head casket issue because exhaust smells and looks fine. Maybe there is such a small leak I never noticed it was getting low. Any thoughts from the community.
Melting Slicks
Joined: Oct 2003
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From: Chapel Hill NC
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Could be a small leak evaporating before it hits the ground. Did you smell coolant after your test run? Id keep a close eye on it for a while.
If you have a blown head gasket you may see bubbles in the coolant. You may also smell exhaust fumes coming from the coolant.
If you have a blown head gasket you may see bubbles in the coolant. You may also smell exhaust fumes coming from the coolant.
Drifting
Joined: Feb 2008
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From: NE Ohio
2024 C4 of the Year Finalist - Unmodified
After driving check overflow level, let cool down to max cool ( over nite is best ) check to make sure coolant returned to radiator. If not check radiator cap.
Safety Car
Joined: Mar 2017
Posts: 4,202
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From: LeClaire Iowa
Your most telling sentence is that the overflow tank was fuller than normal. This points to the radiator cap being weak or leaking. It can also point to the hose from the overflow to the pressure tank is not creating a solid airtight seal to allow fluid to be sucked back on cooldown. Dan
Thread Starter
Drifting
Joined: Nov 2018
Posts: 1,800
Likes: 579
From: Mays Landing, NJ
So today I was finally able to do additional testing on the cooling system. Started the motor and let it sit and idle until it got hot enough for fan to come on. The fan did come on as expected and temp did drop, but not as fast as I'm used to seeing. Went on a short drive through the neighborhood and temp was all over the place. Temp got to the point of boiling over so I stopped back at my house checked the fan and it was still running, but overflow container was starting to overflow.
Looked at the radiator and there was no trash blocking it but could use a cleaning as it's original. Thoughts now are the radiator is the issue or thermostat is not staying fully open. I did look best I could at water pump and saw no signs of coolant around it or drips below it. Does everyone think my next step would be replacing the thermostat and doing my test again ?
Looked at the radiator and there was no trash blocking it but could use a cleaning as it's original. Thoughts now are the radiator is the issue or thermostat is not staying fully open. I did look best I could at water pump and saw no signs of coolant around it or drips below it. Does everyone think my next step would be replacing the thermostat and doing my test again ?
Drifting
Joined: Feb 2008
Posts: 1,537
Likes: 178
From: NE Ohio
2024 C4 of the Year Finalist - Unmodified
So today I was finally able to do additional testing on the cooling system. Started the motor and let it sit and idle until it got hot enough for fan to come on. The fan did come on as expected and temp did drop, but not as fast as I'm used to seeing. Went on a short drive through the neighborhood and temp was all over the place. Temp got to the point of boiling over so I stopped back at my house checked the fan and it was still running, but overflow container was starting to overflow.
Looked at the radiator and there was no trash blocking it but could use a cleaning as it's original. Thoughts now are the radiator is the issue or thermostat is not staying fully open. I did look best I could at water pump and saw no signs of coolant around it or drips below it. Does everyone think my next step would be replacing the thermostat and doing my test again ?
Looked at the radiator and there was no trash blocking it but could use a cleaning as it's original. Thoughts now are the radiator is the issue or thermostat is not staying fully open. I did look best I could at water pump and saw no signs of coolant around it or drips below it. Does everyone think my next step would be replacing the thermostat and doing my test again ?
Racer
Joined: Nov 2022
Posts: 345
Likes: 31
From: Massachusetts
I would not jump to pulling the the radiator just yet, I would let the engine cool and let the cooling system draw the coolant in overflow back into the radiator and then check the level when cold. Air pockets could have been in the system and just maybe it was not full? If you car has a small leak you might be better off press testing the system to help locate a leak. And another thing about debris in front of radiator and condenser not always leaves block the flow, 30 year old car can get grains or sand lodged in the cooling fins, if you have a compressor try blowing through the cooling fins in front. Don’t get to close with high air pressure.
