Overheating WRX
 

Ive just bought a 93 WRX saloon, everything seemed fine when I checked the car over. It was only once I had started running it that I noticed that it took longer for the temp gauge to climb than my last Scoob. When you were driving the heaters were warm but when you sat for a while they went cold. So I thought it was probably the thermostat.

I got a new thermostat today and went to fit it only to find there was no thermostat in the car. I ran it up in the garage and it heated up to half way on the temp gauge and the heaters were roasting, I ran it like this for 25 minutes but the fans never kicked in. I then took it for a blast on the dueler and after 4 mls the temp gauge had went up to high. I took it back to the garage and it was still reading high, the fans were on and the radiator was freezing. Hot at the inlet side but the whole core was cold.

I topped it up again thinking it was an airlock and went out again, this time it was fine on the dueler for a good 20 mls at slightly above 70. As soon as I got back to the house the temp gauge went straight to high and the radiator was freezing. Im loosing water somewhere, there is no white smoke from the exhaust but there is bubbles coming up from the header tank overflow. I suspect the waters getting forced out the overflow. I suspect a blown head joint. The rad does get hot if you leave the car running for a while. One thing though when I left it running in the garage the rad hoses didnt get hard, surely if one of the head joints was gone then it would pressurise the cooling system and hoses forcing water our the overflow?

Has anyone got any suggestions, Dodgy header tank, water pump?

cheers

You may possibly still have an airlock in the system, that would be the first port of call. If there is no airlock then a headgasket maybe gone.

Banny

I just went out just now and started the car, its been sitting for over 40 minutes cooling. There was no white smoke from the exhaust, I would have thought if the gasket was gone some water would have leaked in to the cylinder giving some smoke on startup.

you can get various symptoms for head gasket failure, all or few may be present.
As Banny says it is still a possibility of an airlock, however the fact that there was no thermostat says to me that there is something more sinister going on. Best bet is take it to a garage that can check the coolant for any other gases (cant remember what they call the test)

Leave the car to idle and remove the coolant cap and leave it running like this for a bit, also manually open the throttle by hand (be gentle though and be careful when you release the throttle as the water will bubble up/shoot out from the coolant tank) Keep topping up as neccessary, and make sure the heater matrix is on hot and have it blowing as well.

I'd just take it into a local garage and get them to perform a coolant contamination check, that should tell you quickly and cheaply if head gasket is an issue.

You may or may not see bubbles in the header tank at tickover.

I tried the coolant cap method mentioned above but all it did in my case was spray rusty water all over my engine bay causing lots of steam as I was a little over enthusiastic with the throttle lol - so be careful !

Banny you were spot on it was an airlock, lots of topping up and running later and its now behaving itself. One thing I did do was change the header tank. Cheers