Three months ago purchased a 95 Winstar at auction cheap to use at as a backup vehicle just to drive when one of our cars is in the shop, etc. I religiously check all the fluids. Vehicle is parked on a concrete pad and I have never noticed a leak. On Sunday made a 90 mile trip and the temperature gage jumped to the top. Pulled over and checked the radiator - resevoir was full and the radiator cap was not even warm. Cranked the car and the gage while high was within the normal range. Finished the last 10 miles of the trip.
Four hours later when we left I checked and the resevoir was empty and there was no fluid visible in the radiator. As it was raining could not see any fluid under the car. Took a gallon of antifreeze/water to fill the radiator and bring the resevoir back to full. Cranked the car and let it run - no visible leaks. Decided to take a chance and go back home. No problems. Temperature gage never make it over 1/3 up the gage. Next morning checked the fluid and and radiator is full and resevoir is normal.
After keeping the car my mechanic and pressurizing the system the only thing they found was minor weeping from the timing cover. Told me to drive it watch it and he would give me an estimate on the cost, which would be expensive. He acted like it wasn't a big deal if I didn't do it right now and I might want to just drive it and keep an eye on the fluid levels for a week or so.
No almost nothing about cars, but what I witnessed does not jibe with a "slow leak". Any thoughts.