1991 240
I finished my timing belt and seal replacement including a new water pump and all new belts. Everything went very well. Thank you for all the info here on the Brick.!!!!

Yet I have another question to raise. After running a test drive I noticed the temp gauge going up and up but never reaching the red mark. I turned on the heater and it did come back down. But did not stay there after turning the heat down(off).It kept creeping up to the top.

I had topped off the coolant after replacing the new pump and even ran the engine with the heat open to allow for the coolant to flow into the heater core and then checked my level again.

I know the history of this car and past records show that the previous owner also had issues with the gauge. When the tech's checked it out they always found no problems. And stated the gauge is reading irregular. Also the coolant Tempo Sensor has been replaced somewhere in the last five years.

So is this a problem with the circuit board on the gauge that I have read about fixing to allow normal readings due to age and worn out circuits? Or due I need to look at other areas?

I did replace the T-stat with a new one at 180 degrees, from the old one that was in there at 192 degrees. Could this be the problem?

Also I hear Hissing at the cap on the reservoir tank. I realize it has to allow air to escape but could the coolant be boiling out? I also read that some are switching the cap to the green one but I wouldn't want the wrong amount of pressure to build up in the system due to a different release cap.

Any help here is much appreciated.

Thank you \Judd