constant "low coolant" warning
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constant "low coolant" warning
Hello I own C5 1997 vette, and a few months ago found that the coolant was boilling at around 100 degrees, and a new coolant tank cap fixed this issue entirely for me,
problem is, now i constantly get a "low coolant" warning on my little display all the time, and have checked the coolant hot and cold several times and its bang on,
any ideas??
cheers.
problem is, now i constantly get a "low coolant" warning on my little display all the time, and have checked the coolant hot and cold several times and its bang on,
any ideas??
cheers.
8th Gear
Joined: May 2022
Posts: 8
Likes: 0
I had this problem on my other GM. A mechanic told me it's like never been filled and it's just all air.
Before replacing anything or adding anything to the coolant I would try and find the way to properly air burp the cooling system. It's likely just full of air and not full.
My chevy express would constantly say low coolant even though it was fine, so I followed the GM instructions. It involved removing the rad cap or surge cap, starting the vehicle and running it to full temp (thermostat opens), run for 10 minutes hot (add coolant as necessary). Coolant started to bubble as air started to come up and out of the system, as that happened the level dropped. Then you shut it off let it cool down and come back when it's cold, you'll need to add more. I came back the next morning and the surge tank was empty! Where did it go? The vehicle had not been run since I filled it cold, and there ground was bone dry! Must have been 50 dex / 50 distilled water / 50 air. I put another quart or so of 50/50 dexcool to the cold line. Drove 650 miles over the next weekend and it did trip the low coolant message for just a second on first startup coming back, it was down just a smidge but way better than before. Likely take a few more heat cycles (as the GM instructions say) to fully burp the system.
Removing all the cooling caps and running through the heat cycle seems to let the air bubble out
Before replacing anything or adding anything to the coolant I would try and find the way to properly air burp the cooling system. It's likely just full of air and not full.
My chevy express would constantly say low coolant even though it was fine, so I followed the GM instructions. It involved removing the rad cap or surge cap, starting the vehicle and running it to full temp (thermostat opens), run for 10 minutes hot (add coolant as necessary). Coolant started to bubble as air started to come up and out of the system, as that happened the level dropped. Then you shut it off let it cool down and come back when it's cold, you'll need to add more. I came back the next morning and the surge tank was empty! Where did it go? The vehicle had not been run since I filled it cold, and there ground was bone dry! Must have been 50 dex / 50 distilled water / 50 air. I put another quart or so of 50/50 dexcool to the cold line. Drove 650 miles over the next weekend and it did trip the low coolant message for just a second on first startup coming back, it was down just a smidge but way better than before. Likely take a few more heat cycles (as the GM instructions say) to fully burp the system.
Removing all the cooling caps and running through the heat cycle seems to let the air bubble out
Running Guns & Moonshine
Joined: Aug 2001
Posts: 12,650
Likes: 7,292
From: CT
Visually inspect. Does the overflow tank have coolant to the sufficient line and is the car maintaining normal temps when driving?
If good, you're set. Later C5s did not have a coolant level sensor.
The inexpensive fix is to disconnect the wire under the overflow tank which connects to the sensor and ground that plug wire connection one wire to the other so the ecu is happy and you get no idiot light. Then just check it or check your temps when driving.
If good, you're set. Later C5s did not have a coolant level sensor.
The inexpensive fix is to disconnect the wire under the overflow tank which connects to the sensor and ground that plug wire connection one wire to the other so the ecu is happy and you get no idiot light. Then just check it or check your temps when driving.
