1995 850 non-turbo temperature gauge problem

Fay · Post by **Fay** » 03 Mar 2012, 12:35

Hi,

I have a 1995 850 wagon, non-turbo, that has a problem with the temperature gauge. It takes about 20 minutes for the needle to reach the 'normal' position, about 3:00 on a clock face. Then it won't stay there. Sometimes it just fluctuates a little, sometimes it goes almost to the bottom of the gauge.

I had the temperature sending unit sensor (?) replaced and that didn't help. Then I had the thermostat replaced and that didn't help either. After the thermostat replacement, the mechanic said the temperature reading was about 160 degrees pre-replacement and about 180 post-replacement. Is 180 the normal temperature?

I tried hitting the gauge with my hand to see if something was stuck (we used to be able to fix my mother's Volvo's gauge this way until some cable finally wore out and it stopped registering completely) but that does nothing.

I recently had the water pump and timing belt replaced also but had the problem before those replacements. Once I had a similar problem when the battery was going bad. I replaced the battery and no more problem. But this battery is relatively new so I doubt it's related but thought I would mention it.

Does anybody have any other suggestions for what to tell the mechanic to check?

Thanks so much!

Fay

Post by **jblackburn** » 03 Mar 2012, 13:28

Sounds like there's still a bad thermostat in place. Use a Wahler replacement and see how that goes for you - it's cheap and easy to replace.The thermostat should OPEN at 180 degrees and the fan cuts on around 220 degrees.

Fay · Post by **Fay** » 06 Mar 2012, 10:45

Thanks for the response!

Is there any way for a mechanic to test the thermostat while it's on the car to verify that it's bad? I know there are tons of defective parts out there but it does seem a bit strange that a new thermostat would have the same problem that the old one had.

Thanks!

Post by **Pauloil** » 06 Mar 2012, 19:31

either take off neg cable for 20 min or take it off and touch it to the pos cable. need to reset adaptives. could be bad new temp sensor: i got one once that was bad out of the box. you can see how the resistance varies wrt temperature to test the sensor. search the site for resistance values.....

Fay · Post by **Fay** » 15 Mar 2012, 14:09

Thanks Pauloil for the response!

I have a follow-up question. Now that it's gotten hotter here (South Georgia), the problem is a little different. When I first started having the problem, it took about 7 to 10 minutes for the temperature gauge to register anything other than zero, then about another 10 minutes for it to get to normal. Now the gauge starts registering after 3 or 4 minutes. It still takes a while to get to the normal setting but not as long.

Does that still sound like a thermostat that's stuck open? Or does that lean more toward the temperature sensor?

Thanks for any help!