'89 245 Temperature gauge runs at 3/4 (see photo), rather than sitting at the normal halfway point "dot" on temperature gauge. Over the last 6+ months I have done the following to rectify this:


-Swapped in two 87C/187F new thermostats
-Flushed the entire cooling system twice. There is now 50/50 Volvo Coolant/Water
in the engine
-Installed brand new 3-row, all metal Cryomax radiator from IPD (see my product
review comments on their website). All hoses new.
-Installed new Bosch temperature gauge sensor
-Installed new Bosch engine temperature sensor for ECU
-Temperature Compensation board has been removed and pins 1 & 3 have been
jumpered. I've also done this on two separate gauge circuit boards and tried
them both.
-Swapped in two different temperature gauges from parts cars
-Water pump is a one and 1/2 year old Hepu unit that shows no signs of leakage
and seems to be working fine
-Installed new 11lbs/75kpa overflow reservoir tank cap
-Engine has fresh oil and filter

All that, yes a complete overhaul of cooling system, and the coolant temperature gauge still shows 3/4 hot. I've about lost my mind.

I've taken it to an independent Volvo mechanic and he used an infrared thermometer and checked various spots throughout the engine. Temperatures read in the mid 180's when I get there, mid 170's after it sits there and idles for a while. We've done this twice with the same results. Same results after I pulled the original radiator and installed the $250 3-row. You can imagine how frustrated I am to see no improvement. He says there is no way the headgasket is leaking, but we haven't tested it. Also, no pressure test either, but like I've laid out, EVERYTHING has been replaced. There are no leaks.

Gauge stays pretty much at 3/4. It dips a tad lower when it sits and idles for a few minutes and it actually wavers just a tad hotter when on the highway under load. Running the AC has absolutely no noticeable affect on the gauge position (i've installed an aux electric fan to run when rheostat is on).

With all my appeasement to the Volvo Gods, I want my temp gauge to sit at 9 'oclock, as it should. I'm pretty much resolved to saying to hell with it, it has to be running right, and I should just ignore the gauge.

But I can't. There has got to be a fix.

Does anyone have any theory's given all this information?

Thank you,
Jason