‘98 2.3CL 210K miles
New rad (old one sprung a leak)
New tstat and all coolant hoses
Car’s been running fine the last few months (that’s when the rad / tstat and hoses were replaced).
The last few days the car temp is perfect driving around town (and the fans kick in normally) but climbs up to the half way mark on the highway. Slightly higher when going up hills on the highway.
I ruled out the tstat being bad today by removing and testing on the stove top (per the service manual. I also filled the rad with the bleeder on the tstat housing open. So I don’t think there is air in the system.
Now I had the timing belt and water pump changed 80K miles ago, but honestly I don’t trust the place that did the work so you never know (could be the original water pump)….
As an experiment I down shifted on the hills to up my RPMs. And guess what,,, the temp did drop down. Making me think the water pump is not working at the required efficiency and the higher RPMs are needed to get enough flow through the rad. Do these water pumps “wear out”. Are the impellers plastic or metal? I was going to replace the timing belt / water pump soon anyway, might have to put a rush on it!