Here's what's going on:
- The temperature remains constant on the highway.
- The temperature remains constant for short trips.
- The temperature generally remains constant when the car is not moving. (It sometimes creeps up at long lights.)
- For longer trips, the temperature increases when I accelerate from a stop.
- Eventually the needle will get to about 75% - 80% of maximum. Then the temperature will drop back to normal. Then the process will repeat.
So far I've replaced:
- Engine: Head gasket was venting into the coolant. (The shop did a "sniff" test). I got a re-manufactured engine put in.
- Water pump: Replaced it when the first radiator went to heaven.
- Various hoses as they fail.
Any thoughts about what could be going on?