Head gasked started seeping coolant to the outside of the engine beneath the #3 exhaust port a couple of years ago. I stopped the leak with some radiator sealant, but that is not a long-term solution so I promised myself I would replace the head gasket next time I did the timing belt.

When the car set a code for the temperature sensor, I ordered a new one. Then I determined that it is virtually impossible to replace the temperature sensor on a California '91 with the intake manifold in place. I spent an hour pulling off components and unbolting the wiring harness from the side of the engine just to unplug the lead to the sensor, and realized that I could not possibly plug it back on.

Since it was time for the timing belt, and I have had the head gasket set hanging on the wall for the last two years, I went for it. Replacing that temperature sensor with the head on the work bench is definitely the way to go.

There was no visible evidence of leakage on either side of the head gasket when I pulled it off.