Thanks kbeachy,

Can the engine coolant sensor alone cause the car to overheat, stall?
Testing the water pump later today...

 

From working with my Saturn, I found out that the engine coolant sensor reports to the computer on the temperature so that the computer in turn can tell all the other items it controls how to behave based on those conditions. That resulted in the engines in both my Saturns running too fast. I tried everything else I could think of to fix the idling problem--throttle position sensor, idle air control valve, cleaning throttle body, idle adjustment screw--and amazingly none of that helped except for when I changed the coolant sensor.

So I would suspect the engine coolant sensor for the stalling, but I would look for something else causing the overheating. The coolant sensor is relatively inexpensive and easy to change, so just by process of elimination you can see if that's the problem.

For overheating I'd look at water pump, thermostat, coolant level, condition of radiator, any leaks. If you could describe the pattern for how the engine runs hot that can help in troubleshooting. Hope that's helpful.

 

Has anyone had any trouble with these weird bolts that connect the radiator house plate to the thermostat housing? They don't seem to be screwing on (or off) correctly - is it because they're threaded in two directions? Are these the right bolts for this connection?

the plate connected to the radiator hose

https://www.dropbox.com/s/mlw9s8bszr...2000.15.38.jpg

the bolt close-up

https://www.dropbox.com/s/1uo2bojzxe...2000.07.43.jpg

Connecting to this plate, which holds the thermostat

https://www.dropbox.com/s/ctaw3j32jh...2000.08.51.jpg

 

The whole fitting has pulled out there - not just the hex bolt.

The knurled section (arrowed in red) should stay in the housing and the hex bolt (arrowed in blue) unscrews from it:



The hex bolts must be in VERY tight to strip out the fitting. The correct torque for thermostat cover bolts is only 8 - 10 Nm.

You may be able to repair by first separating the bolt from the knurled section and gluing the knurled section back into the housing.

Graham

 

I ran into this issue- replaced the housing.