Hi,
my '91 245 had been showing 'cold' on the temp gauge for a while and I had the thermostat replaced by a good volvo indie mechanic. We discussed the symptoms and he knew about the whole compensator board issue. Immediately after he did it (late Fall) the gauge read 9 o'clock. But within a week it was back to it's old position around 7:30, sometimes going down to 6:30. His take was that if the car made 'heat' sensed by me through the vents then this was a version of the compensator board problem but basically not a big deal. Things smoothed out and in my normal commute it has been sitting around 7:30, but blowing lots of heat.

This past week as the air has become damper (I am in VT) and warmer I have noticed the following behavior during my daily commute (15 miles each way).
1. Early in the a.m. the car warms up gauge reaches 9 o'clock.
2. Gauge reads 9 for 5 mins or so (speed/distance don't effect it)
3. Gauge drops to 6:30-7. Stays there for remainder of trip (10mins).

Often, if it has been warm (around 30F or higher)during the day the gauge won't get above 7 o'clock all the way home.

This doesn't fit with the wilder fluctuations most people report due to the compensator board problem. Other things I have begun to think about include the sensors.

Any advice?
cheers,
Rod

I'd get rid of the temperature compensation board. I did it on our 93 after the temperature gauge stopped rising at all. Cured the problem. The job was a piece of cake. I followed a suggestion from an experience and active board member and used a bit of scrap lamp cord cut to just the right length and pushed it over the two pins. It was held in place very securely when I put it all back together and has been great for three years.
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Thanks for all the help. DougC 1981 242, IPD bars and Turbo wheels, M46 :::::::::::::::::: 1993 245, B230 NA L-Block, M47, Turbo bars::::::::::::1984 760, B23FT, M46, waiting to donate engine to 242

I would place the compensator board into the landfill and jumper 1&3. That will narrow down the problem. T-stat at 82C, 87C or 92C won't have much of an effect on the coolant temp after the engine has been running 20 min or so.
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1986 Volvo 245

It almost sounds like you have too cool of a thermostat.

The car warms up the thermostat delays in opening (that's when you read 9:00) then it opens, too much, and the temps come down.

Is it possible that when you had the Comp board and thermostat done that a very cold T stat was put in?
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'75 Jeep CJ5 345Hp ChevyPwrd, two motorcycles, '85 Pickup: The '89 Volvo is the newest vehicle I own. it wasn't Volvos safety , it was Longevity that sold me http://home.no.net/ebrox/Tony's%20cars.htm

Hi Tony,
Just to clear one thing up.We didn't fix the comp. board, we just talked about it as a possible cause.

We also talked about how 'cold' or 'hot' a thermostat to fit. We opted (if I remember right) for somewhere in the middle. The car has the heavy duty copper rad fitted, maybe what I should do is fit a thermostat that is hotter.
cheers,
Rod

You should be using the 87 C thermostat. Dan

Ohhhh, Then I would point to that board as the main suspect.

After pulling the Board out, you can jumper the pins out easier from the back of the cluster. Much easier then trying to squeeze a soldering iron in the front through the gauges.

I'm thinking at a 7:30 reading, your thermostat would have to be 160 degrees at the highest.. I'm guessing you may have a 180 in there if you went middle of the road.

'91 Not sure how easy it is to pull the cluster with a car wit Airbags. But taking that Comp Board out will eliminate one variable...forever. The gauge reads really solid with it eliminated...You wont miss it.
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'75 Jeep CJ5 345Hp ChevyPwrd, two motorcycles, '85 Pickup: The '89 Volvo is the newest vehicle I own. it wasn't Volvos safety , it was Longevity that sold me http://home.no.net/ebrox/Tony's%20cars.htm

Hi Tony,
yes I am leaning that way. I would rather know what I am getting!

thanks,
R

Maybe there is some kind of gunk sitting on the sender in the block?why not take it out&clean it/Or do a real good flush&then if the antifreeze was good put it back in.