This has happened to me twice. On the freeway at like 70 mph, my CRX's needle starts to climb up to like 1/2 to 5/8 of the gauge (at operating temp i'm at 1/3 or 3/8). It seems to only happen on hot days, and it seems to start on the freeway, and then the problem lasts for a while as i drive back home.

If i stop the car, the problem goes away most of the time (but not always). The needle seems to drop really fast (from like 5/8 to 1/3 on the gauge in a second or two). When i idle my car in the garage, the temperature drops quickly and stays down. Fan comes on.

My car is a turbo b18c crx, so it's really hot in the engine bay, and I'm running reflective wrap to bounce the heat away from my hood. I have a dual core half width radiator and an intercooler in front of it. Fan is wired the right way.

Any ideas?

Thank you

 

how old is hte radiator ?