Beginning with the 1986 240s Volvo in all it's infinite wisdom discovered a way to reduce the number of service calls about cars running hot. (This is my theory, no facts.)

To do that, they installed a Temperature Compensation Board. It's in the instrument cluster, and smooths out the movements of the temp gauge needle. It usually goes bad after 10 or 15 years, and readings are more random than useful.

The accurate gauge, without that TCB, would show that on a cold start the needle would move up towards the red. After the thermostat opens wide the needle would drop to the normal position. All my pre-1986 240s did that.

Often an owner will install a bypass to remove the TCB from the circuit. That may be the case with your car, in which case you should the the rise and drop described above.

After running a hour (maybe less) the temp should be normal and stay there for as long as you drive, unless you are pulling a long steep hill.

So, are you saying that your temp gauge settles out at an above-normal reading?

Good Luck,

Bob

:>)