1992 Volvo 240, 150,000 miles +/-.

A couple weeks ago my temp gauge soared up to almost the red zone. I replaced the thermostat and the coolant sensor. I also took out the compensation board and put in the temp board bypass from IPD. No issues putting the wires on the cluster. The speedometer and gas gauge both work fine. The clock has had issues since before we purchased the car over a year ago.

The temp gauge is now only registering just above the bottom (coolest) line. It will rise just slightly after the car has been drive 15-20 minutes and may go back down. Back before all this started it would normally run just under the half line.

Should I be concerned? Coolant is fine and no apparent issues.

Car runs great!

-Norm

 

Well, did you do the bypass right? If it works at all, probably you did fine. Try to get the car hot (hot day, idle, etc.) and see how far the gauge will go. Probably it's registering OK...

 

Thank you. It was about 95 degrees here today. I drove it for about an hour in the heat of the day. Temp gauge went to an estimated 1/16 above the bottom (cool) line, so it did rise just a bit. When doing the bypass, I double checked my wiring 1st and 3rd pins according to the IPD directions.

 

my temp gauge sometimes does strange movements. i have not done the bypass on it. the engine does not overheat though....
i would be really concerned if it ever pinned to the top in the red zone but at worst it ends up just below that, and the heat works well. i don't worry too much about it and always make sure the coolant level is good.

 

On your new thermostat what temp rating did you use? Also what brand? I live in the midwest and the car originally was equippted with a 92C temp Wahler brand thermostat. This is what I always run and is the best compromise for the wide variations in temp we get here. In the south you may want to go with a lower temp rated thermostat. Either way, with the compensator board removed, the needle on you temp gauge will vary much more than it did before.

I personally run with the compensator board in and haven't had any trouble. It moves to the red when getting too hot and stays low if the thermostat is stuck open. Pretty much all I need. If I want a good temp reading I would opt for a more accurate aftermarket gauge.