Coolant level warning but no overheating?

[BAYEMVAY]

My '89 M20 coolant continues to disappear. In the morning, I top it off to the 'COLD' level of the expansion tank, but it the coolant level sensor sends the warning every evening after only about 75 miles of driving. After the engine cools, there is some residual coolant at the bottom of the expansion tank, but not much. There are no visible leaks during or after driving, I've bled the air out of the system (The temperature gauge did display an overheating condition before I did so) as instructed on this site and the manual. I've replaced the thermostat and the cooling hoses firm up after a warm-up period.

If my coolant is disappearing, why doesn't my engine overheat? It doesn't seem normal, but except for the 'coolant warning' indication, there would be no indication of a problem.

[Jeff N.]

Are you using antifreeze? Do you smell antifreeze in the exhaust?

[632 Regal]

you wont overheat until the water level is too low to continue to cool the engine, the coolant level warning just says your low. You have to isolate the leak somehow. It either is running into the engine or you have a leak that may be leaking ONTO the engine somewhere and boiling off before you see a drip/leak.

[BAYEMVAY]

Thanks for the responses.

I have actually randomly pulled over to try and 'catch' evidence of a leak but found none.

I'll check for anti-freeze smell after work today.

[632 Regal]

Thanks for the responses.

I have actually randomly pulled over to try and 'catch' evidence of a leak but found none.

I'll check for anti-freeze smell after work today.