Hey guys... wanted to run something past you to see if it makes sense.
I had drained + filled the cooling system to replace the small lines between the pipe and oil cooler (sandwich style).
I drove the car around and did a quick trip around town - I topped it up as it was just low enough to trigger the low level light.
I later had it idling for ~10 minutes as I tried to sort out another little issue. Went to get back in the car and saw that it was pulling temperature - 230ish deg. I immediately shut the car off as the catch can was starting to overflow on the ground. Waited a minute with both fans running and re-started the car to get it cooled down. However, when I re-started it collapsed the upper coolant hose. Shut it down, removed rad cap, and it came back out to shape. Repeated it again with the rad cap on and then off, and finally started to see coolant flowing again. Topped it off again and continued on.
I *think* what happened was that I had an air bubble in the cooling system. But what confuses me was that it didn't show up immediately instead of driving for an hour plus. Either that, or possibly that the t/stat is starting to fail? I know the cheaper ones fail closed and the good ones fail open - I'm not sure what's in the car.
Either way, the car still isn't keeping temperature down very well - If it's slower speed stuff I need to keep the a/c fan going to maintain temperature otherwise it'll start to creep a bit. Best course of action? Is the best way to bleed the system just to run it with the cap off? I suppose another quick job would be to replace the thermostat and see if it makes a difference.
The cooling system is stock - The rad was replaced a few years ago and the hoses are all in good shape. Could the water pump be starting to fail?