Hello car gurus. .. I need some help and ideas. I have had my Saturn for two and a half years. I just changed the thermostat and the temperature sensor. As I'm driving down the road my temperature gauge just gets below halfway and my car kills everything. Like it is overheating. The fan doesn't kick on unless you have the AC running, but from what I've read on here and other places it's not supposed to until it gets about 3/4 of the way up. The engine light is not coming on nor is any other lights. Once the temperature gauge reaches that halfway point the car is just dying until it cools off a little bit. I haven't done any technical things per say like compression tests, nor have I messed with the fan relay. I don't have the cash to take it to a mechanic so I thought I would try here for suggestions or ideas. Can anyone help... could it be the crankshaft position sensor? Or am I totally off?

 

I'll ask before the others, did you use a factory GM temp sensor? Aftermarket sensors have been unreliable at best. I assume you had the same symptoms before the parts replacement and no change since. If you have had no change in symptoms then a crank position sensor is a logical guess. Do you have a simple code reader?

 

02 Lw300
No I dont have a code reader can AutoZone read that code even though no lights are on or do they have something like that ?and I just bought the sensor at AutoZone which is probably the aftermarket. You are correct though I'm still having the same symptom I let the car run, the temperature gauge just reaches under the halfway point and everything shuts down. After hearing that do you think it would still be the crankshaft sensor?

 

Derf knows S cars much better than I do. And no Autozone will not be able to help. My Snap-on scanner would work to diagnose your car. If there are no trouble codes you need to see what quits when at temp. A scanner that gives a data stream will see what quits not a code reader.

 

Ty...I sent Derf Message. I'm going to pick up a crankshaft sensor today so hopefully that is the problem. From what I've seen they run between $16.99 and $18.99 but I don't know if that could be the problem or the solution,. In any case I'm going to get it changed today hopefully and then I'll let you know if that was The Cure or not from the things that I've read on the internet I don't know if changing that will help my symptom right now it's just the most inexpensive option and while I'm under the car I can check the plugs and things around the starter because I did just replace the starter and I may have bumped something under there but this had happened once before I changed the starter. If this don't work and I don't have any other suggestions I may wind up taking it to a shop when I get paid which I absolutely cannot afford.
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When you say you changed the coolant sensor, what is the location of the sensor you changed? You should probably replace the ECTS (electronic coolant temp sensor) in the side of the head with one from a Saturn friendly GM dealership. It NEEDS to be brass tipped. The rosin tip on the aftermarket junk (like AZ sells) are NOT calibrated correctly. You should also get the pigtail connector to go along with the ECTS. Together they'll run you about $50. I used to work for both AZ and Advance and know from experience that the sensors they sell have a high failure rate. Get a genuine GM/AC/Delco part and you'll probably see your car start performing right. If you still have the old sensor, look at it and you'll see what I'm talking about. And the pigtail has a squeeze connector. Make sure your old one isn't cracked, like mine was.

 

Rubyhayseed/02 Lw300
Thank you both for the advice I did run to AutoZone and I picked up a new crankshaft protection sensor and replaced it and now the car still heats up to the halfway point but it is not shutting off like it was everything does not go dead. RH, yes the coolant sensor that I replaced is on the head I watched a video first on how to replace it(the sensor). So far after taking the car for about a 15-minute drive as I said it heated up but did not shut off so the thing I'm going to do next is I'm am going to put the proper antifreeze in it hence the orange stuff. After all the years of driving I didn't realize there was actually a special orange antifreeze that had to go into this car I guess that's what happens when you come from a generation where my first car was a 1979 Chevy, Malibu.

 

79 Malibu? My first car was a 1948 Plymouth Special Deluxe Coupe! Flat head six, three on the tree. You must be a young man.

 

Sorry -- I've been away from the board.
CKP would have been my 1st guess as well, somewhat easily confirmed if when the car shuts down, you get under the hood, pull two wires of the same coil pack (do not mix up), pull the fuel injector fuse, crank, and watch for an arc between the two (sometimes hard to see in daylight. Optimally you'd VERY GENTLY pull a spark plug, ground the outer electrode, crank and look for spark.

CKP bad = no arc and no spark (respectively)
CKP good= arc n spark

(put fuel injector fuse back in!!!!)
Gently replace and very lightly torque the spark plug; messing with plugs in a fully operating temp scenario is not something you want to do w an aluminum block any more than you have to.