Hey Everyone,



I've gotten a ton of work done to the car over the last few months, so i'll just start with those items and lead up to the current symptom.

1982 244 DL B21F with Chrysler ignition/KJet:

prior to any work, the car had been ok during the summer as far as temps...the needle would hang out at 9:00 except when i drove faster than 70 with A/C on. It would climb to 9:30 but after I turned the A/C off it would creep back down. Slowing down also helped.

I finally got around to obtaining a brand new engine harness from davebarton.com, and though it was quite a bit of work, i'm very happy with the results. In the process of putting in the new harness, I also found a few items that either needed replacement, I broke them during teardown/rebuild, or just the old "since i'm here, might as well do it"

As pertaining to the cooling system I replaced the following within the last 2 months/1000 miles:
water pump
thermostat (87C OEM volvo) and housing
all sensors on the engine block were replaced
fan clutch (tropical)
all coolant and heater hoses
all accessory belts
OEM Volvo coolant overflow tank and cap

I also disassembled the intake manifold/throttle body and cleaned them thoroughly along with the intake ports. Cleaned the AMM assembly as well and installed a new air intake accordion hose along with all new vacuum lines. Flushed the entire cooling system with distilled water and radiator flush 3 full cycles, then filled the system with Volvo blue coolant. No leaks have been found anywhere. Have not had the system pressure tested yet.

After all that, the car began to run better than she ever has, with temps holding normally. Then out of the blue the needle shot up one day after startup and a 2 minute idle. Now it shoots up every time I start the car and stays right at a needle's width away from the red marker (or 9:30 using Art Bernstein's protractor confirmed measurements)

I replaced the new thermostat again with the same PN, no change.
The coolant sensor (yellow wire) is brand new as I stated before. I did disconnect the wire and grounded it to make sure it spiked to the red, which it did.

When i get up to 70mph, the needle stays where it is, right at 9:30. Blasting the heater makes no difference either, even when coasting down a long hill in neutral.

I've read in other posts that I should possibly consider the head gasket could have a hot spot and hasn't yet failed. I have no mixing of coolant/oil anywhere, and even after a 70mph run, I smell no hot coolant through the vents or under the hood. The radiator has a couple bent fins, but no blockages from insects and the like. Today I picked up an IR thermometer and read the T-stat housing just after a highway run. First readings were between 140-150 degrees, then I put some electrical tape over the housing and read it again. Those readings were 170-180 degrees. I also read the return hose and core area and got no suspicious readings.

It seems like the only options left are either a bad (new) sensor or gauge. Fuel tank gauge is reading accurately as a reference, and how often do the gauges really go bad? Oh, I also just read about the pressure relief pin inside the thermostat, and that it should face upward at 12:00...is this vitally important? I have no idea how it's currently situated as I've never heard about this before. It could very well be at the bottom for all I know.


Can anyone contribute any other suggestions or ideas, or am I on the right track here? I'm away from the car for a few days so I figured I would try to get some assistance from the board before I go back for the next round.

Thank you again for everyone's time and contributions.