My 940 overheated yesterday and blew out the plug on the side of the radiator. Lost most of the coolant. I assume this is the reason for the plug. I found the plug and grommet and put them back in. I found out that the cause of the problem was the electric fan blade is broken off the motor. I hit a deer several weeks ago and didn't notice the damage, but will take it to the body shop on Monday. The car sat idling a good while for the first time since the wreck.
My question is this: I refilled the radiator with water to get me home and the temp gauge read normal. Today I refilled the overflow tank again, ran the car for about a half hour of speeds of 50 or more, and the gauge read a bit below normal. Just came home from a 50 mile trip and the gauge dropped to the full cold position, with minimal heat from the heater. Coolant (water) level is fine and it ran normally. Could the use of water cause this? If not, what sensor do I need to check? Outside temps are the same as they have been lately (In GA, I won't need to worry about freezing for the next few days)
Thanks for the sage advice I always get from this board.
Mark
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'94 940 Wagon, '84 240 turbo sedan