Anybody any ideas what would cause this, could it be thermostat?

Dont think head gasket as no water in oil or vice versa, well i hope not anyway.

Heater only messed up last night too and today its overheating. will run it for while with rad cap off to try and get rid of blockages if any.

 

Could be an air lock, or the thermostat isn't opening properly.

I had my head gaskets go not so long ago, and affects were, overheating at random points of the journey, juddering when on boost, then eventually gave up.

 

Remove the thermostat and see if the problem still occurs,if not then buy a new stat and jobs a good'un

 

Think i will leave into a mechanic as few guys said it could be head gasket of ran with no antifreeze. Hope not.

Just ran it there with rad cap off and idled it and it didnt overheat but bubbles were in header tank even without pressing any hoses.

 

either thermostat or water pump mate.

 

i had exactly the same problem 2 weeks back when the temps droped down to -6c. it turned out to be my heater matrix had frozen up, i just left the car a few hours, the hot water from the engine thored it out by its self and it was fine again thank god. get the water droped out and put fresh antifreeze in. hopfully you havent done any more damage. try squeezing the two pipes under the right side of the intercooler going through the bulkhead to see if there frozen. hope you get it sorted bud

 

Not head gasket guys, knew it wasnt as bit to sus that when it freezes at night head gasket would go just like that. Took rad cap off and pumped the bottom rad hose for ages till got warm and no bubbles coming from header tank. Looks like there is no anti freeze in it. Car heating it blowing real hot again and car not overheating.

So will go home and let a litre out of header tank and fill with antifreeze so hope fully doesnt happen again. That should be enough a litre, shouldnt it or would i need 2?

Cheers.

 

subaru engines take 3 ltrs of anti freeze

 

i think i put 2.5l in mine

 

What you do is totally drain the system and refill it with and pre mix it it 50:50 (water:antifreeze) whilst filling (very slowly) until the header is half full and run the engine until warm with the cap off to remove any air. Replace cap when it starts to overflow. Switch off, cool down, then top back up to full.

Don't bodge it! You've had a lucky escape already!

 

A couple of years ago we were on the way to the garage to put the car in for oil change etc. We were about 1 mile away and I noticed that the heater was still cold yet the water temp was thro the roof (or thro the wrong side of the gauge if you like!).

Head gasket had gone

Hope yours isn't this as it was quite pricy to get it sorted.