2001 Saturn SL1 overheating

JOKERSWILD10

MEMBER
2001 SATURN SL1
193,000 MILES

Iam new to the saturn world, so any help would be great. 2001 saturn sl1. We can drive the car roughly 10 miles/ 10 mins, slowly over heats, gets to the red line but I havent allowed it to go over. We turn the heater on full blast, temp then begins to drop. I replaced the thermostat, the problem continues. Some days it raises, but not all? A/C dosent have to be on to over heat, it does it anyways. PLEASE HELP, THANK YOU

1 Reply

CARADIODOC

MECHANIC
33,871 POSTS

Your car is at the age when corroded cooling fins on the radiator are a good suspect. You found the dandy clue. Running the heater brings the temperature down. The heater core is a small radiator. The other clue is natural air flow at highway speeds doesn't bring the temperature down, and in this case running the heater does.

This happened many years ago on my '88 Grand Caravan. At first it ran warm above 60 mph and when air temperature was over 60 degrees. Eventually it occurred as low as 35 degrees, and at lower speeds. I had to run the rear heater most of the time. The cooling fins crumbled like a rotten chocolate chip cookie! After patching 14 GROUPS of holes in the corroded tubes over a period of a couple of months, I finally replaced the radiator and the overheating was solved. It's still my daily driver and that radiator is still in there.