Okay I have a 1993 Volvo 240 and I believe it is running warm. I'm a big tbrick member (sorry) but this is my first post here. So far I've..
-Bypassed temperature compensation board (correctly)
-New radiator
-New thermostat (tried 195 and 180, the 180 reads lower but still above 9 o'clock a little)
-New temp sending unit, the one that has one wire leading to gauge-Swapped entire clusters with my other '93 240 and got the same readings.
-New waterpump
-New coolant
-I disconnected the female portion of the temp sending unit and grounded to the intake manifold, this caused the needle to spike well into the red zone, I believe this indicates a properly working gauge.
The temperature is very consistent and doesn't bob up and down, just rises steadily. Also the mechanical fan draws a crazy amount of air so I know it's doing its job.
I'm left thinking either a blown head gasket or excessive resistance in the 1 wire that leads to the gauge. If anyone has a chart that will give resistance that would be awesome!