For the past 2 or so months I have been losing coolant on my '96 Cutlass Supreme. My mechanic did a pressure test and discovered a bad water pump and timing belt cover. I went ahead a got him to change both. I got the car back a Monday drove it around for a bit everything seemed fine... By the weekend I had to drive the car on the highway for 350kms (220miles)... I was in stop and go traffic for a bit and the low coolant light came on, however the temperature gauge of the engine was perfect so I thought nothing of it.. When I got to my destination the reservoir was pretty much empty... So I topped it up to the cool mark and did not drive the car for a few days. I had to drive back home 350kms (220miles) and right away the low coolant light came on, when I stopped for gas I topped up the coolant again and went on my way. The light came back on and the engine started to get hot... So I pulled over and got it towed back to my mechanic. He did another pressure test and couldn't find anything, he then took it for a drive for about 30mins, did another pressure test and found a pin hole leak at one of the freeze plugs (he called it a welsh plug). He fixed the issue and everything seemed fine. The next day in the morning the low coolant light came on again... I topped it up and drove it on the highway for 400kms (250miles)... The light did not come on... The next morning I checked the reservoir it was full and the rad, it was full... The low coolant light came on again and about 10 minutes into the drive it turned off. I drove the car for about 160kms (100miles) no issue with the engine temp or coolant light coming on... This morning I parked in a garage with some cardboard underneath and had a few drips of red coolant... The reservoir was a bit low and however the rad was full... When I cranked on the car the low coolant light was on again.
I don't think the car is losing coolant from a blown head or lower gaskets. Any ideas where it might be going? It always seems that low coolant light comes on when the car has not been used in a few days.