I have a 1992SL2 and its overheating. It only overheats when you are stopped at a stoplight for too long. I replaced the radiator(three weeks ago), thermostat( two winters ago), heater core(two winters ago), and the ECTG sensor(with the radiator)so far. When we start the car, the thermostat light is on, even before the car begins to get hot. Granted the car has been sitting for a year. I would appreciate any feed back...Thanks!

 

Hmmmm lots of possible things here.


1. Is your cooling fan running when the car is hot? (Possible defective fan, fan thermostator fan relay)


2. Does the cooling fan run when you switch your A/C to max cooling and internal circulation?( If #1 is "no", and #2 is "yes", very likely a bad thermostat)


3. If the fan does not run with either #1 or #2, check for defective fan or defective fan wiring


> DO THE FOLLOWING ON A COLD ENGINE<


4. With the key removed, check for loosness of the fan (the bearing goes bad sometimes and allows the fan to wobble, and not get up to speed)


5. Open the radiator cap, and start the engine ... look for bubbles/foaming in the coolant (possible head gasket prob)


I''m sure there are other possibilities, but these tests should catch the majority of the issues. Good luck ....

 

I just resolved an issue with my (new to me) 97 SL2. Coolant disappearing and the double-red coolant warning light flashing. This light flashing does not mean overheat - it means low coolant. The temp guage never got to half way. The smog-test guy said it did this on the dyno too - and he pointed out that the fan never came on. When I topped it up and let the car idle till hot, a bunch of fluid leaked from somewhere around the top of the plastic tank (I wasn''t watching, so I wasn''t sure if it was the cap or a split in the tank). While driving the coolant vanished again without any sign of drips.


I replaced the engine coolant temp sensor (ECT) and the coolant filler cap, and topped up the fluid. Now the fan works.


I think the cap replacement was the fix, and here''s why.


Most cars have a radiator pressure cap on the radiator and an unpressurized overflow tank. On this car the plastic tank is part of the pressurized system. The pressure in the system raises the boiling point of the fluid, and normal running temperature is above the normal boiling point. So if you have no pressure in the system the fluid boils off before it gets to normal temperature, so the fluid disappears, the temperature never gets up to the middle of the guage (where it should be) and the fan never comes on (it triggers when the guage hits 5/8).


When the car is hot, unscrew the cap slowly part way (think two-litre coke bottle you just dropped). If it starts to hiss, screw it back on - the pressure is fine, you have some other problem. If there is no hiss - there is no pressure.Get a new cap.


I posted this because I searched the forums high and low and saw a lot of people withvanishing coolant problems and nobody said "just replace the cap". It is cheap, easyto test, and easy to replace.Woulda saved me two days of head-scratching and a few bucks.


Al

 

On "many" late 80s cars and newer the overflow tank it the only place one can add coolent. "Most" early 90s cars are the same as your SATURN.

Radiator caps have been letting preasure excape from systems from the beginning of radiators causing a loss of fluid as a liquid or as steam.

Cooling should come on at "about" the 3/4 mark

Cooling fan should be on when ever the A/C is on.

This information is posted all over the internet and in most every car forum no matter of the brand.Edited by: sw2cam

 

The difference is that on the Saturn, the tank is not an "overflow" but a header tank and part of the pressurized system, so the integrity of the cap on the tank actually matters. Unless the operator/mechanic is familiar with this relatively unusual setup, the assumption is made that the cap on the tank is unimportant when in fact it IS the radiator cap.

 

Like I said that setup is used on many cars other then SATURN. Any cap that is holding preasure would then be important, an to go by any other assumption is just that, an assumption. Just as you assume its an unusual setup.Edited by: sw2cam

 

Even though this is a very old topic. The cooling fan will activate on a 1992 S-Series when the needle is almost to the red. This is normal. So the original posters car might be operating normally.

 

Well, it''s unusual on cars I''ve owned, which is my reference point.

I think we are agreed that checking that the cap on the plastic overflow/header tank for pressure should be high on any troubleshooting list for cooling issues on this car.

My point was that it often is not on that list, including the list above. Even if this is an old thread, people like me read them for hints.

enough already

Al

 

Checking the preasure cap should be the FIRST thing checked on any car that is overheating or low on coolant. Edited by: sw2cam