The overtemp light on my son's 97 SL1 came on yesterday on his way to work. I drove down to were it was parked and took a look at all the fluids, the transaxle fluid was a bit low (still looked good). I topped it off and he drove it home after work wtih no issues. (the drive is only a few miles). (I had planned on changing all his fluids this weekend)
He gave me a call this AM, after driving a few blocks, the overtemp light flashed 2x then went off, I told him to take the car home. He claims he has not noticed any hard shifts. The temp gauge stays below the half way point and I can't recall that the fan has ever come on other then when AC is running. ( I hadn't paid much attention to it as the car seems to run cool).
Any tips on what to look for? He's had the car for a few months and only has put 3k miles on it. Oil/tranny fluids and filters were replaced when we got it.

The car just hit 90k

Edited by: SaturnDad

 

1) Replace ECTS (Engine Coolant Temp Sensor) and connector with brass-tipped replacement. Originals were resin-tipped and fail, sending info to the PCM that says the coolant temp is -40....

Internal corrosion on connector will ruin the signal from a brand new temp sensor, so replace the connector (Saturn part only).

2) Intermittent flashing temp light when temp guage reads fine (though in your case your ECTS may be faulty) is usually caused by a bad coolant level sensor, sensor wiring issue, or the sensor not being fully immersed in coolant (b/c coolant level is low). Sensor is located in the bottom of the coolant expansion reservoir (where you add coolant).

For the record, the aux fan won't come on unless the A/C is switched on or until the temp rises such that the temp guage reaches about the 3/4 tick--this is normal behavior for an S car engine.

Derf