Had overheating issues with my subaru wrx 2001 bugeye a few months back due to a cracked radiator allowing air into the system. i fitted a new radiator and thermostat. all fixed and was ok. today it started to overheat after 15 minutes down the motorway. when i stop it cools down again, and you can see the temp gauge trying to cool whist driving, the gauge dont get in the red but its up there. all coolant levels good and heaters working and no weird noises. not had chance to have a good look around as works in the way this weekend but has anyone had the some problem. is it worth flushing the coolant system.

 

When you had the initial radiator problem was the temp going into the red? Could be worth flushing out as there may be some crud in the system

 

Put the thermostat in a pot of boiling water to check it opens. Its not unheard of to by a faulty new stat, especially if its a non genuine item.

 

Airlock? Sounds like it.

Drain all coolant, and refill AFTER doing a search on here for "how to" without airlocking again.

There is no known method of bleeding air out of the coolant system once it's in

 

when i had the initial radiator problem it was in the red and smoking, you could tell it was hot. that was four months ago and its been fine up till now.

 

bottom end needs rebuilding...

 

update on the heating issue, it was the thermostat that was faulty. Thanks for the replys.