yabbadoo4

iTrader: (8)

googled around for the answer but no definitive results so anyone know what temps a newage sti shold run when hot and properly up to temp? had a coolant change yesterday and when i got back home the top rad hose had sucked flat! loosened the rad cap and a big sook of air and the pipe opened up again. theres clearly an air lock in the system. so went for a bit of a blast to get her hot and when i slowed down and pulled over she hit around 105 c when i was stationary which is around 220 f. is this a safe temp? what temp is considered to be dangerous or bordering on lunching the engine? the temps came down quite quickly and the car seems fine, have run for 10 mins with the cap off and squeezing top hose and have got a good bit of air out. that was pressing on a bit on that drive but normal driving its sitting arond 90-95 when warm. thanks for any info

Neil XR

iTrader: (1)

i hit around 97'c running flat out on track and running around normal about 84'c

yabbadoo4

iTrader: (8)

cheers m8. mine is running hot compared to yours then. just to add ive just been to the shops and checked top hose and its sucked flat again? there is obviously a Vacuum. is that normal as i thought it would be pressurised? could the radiator cap be knackered?

fat-thomas

iTrader: (4)

Air lock....

piehole1983

iTrader: (7)

Who did the change?

It needs to be refilled slowly via the turbo pipe to get all the air out properly. Worked for me!

yabbadoo4

iTrader: (8)

first thought was air lock as well. isnt the cap supposed to open to release the coolant back from the expansion tank hence the vacuum. if the cap is sticking or not working then it would just suck the hose flat? or a blockage in the expansion bottle hose?

piehole1983

iTrader: (7)

The header tank cap only maintains system pressure by releasing the excess air, if any, to atmosphere and coolant to the overflow bottle.

Not sure what's happening to your car but as already said by Thomas, probably an air lock. Drain out and refilling is the best option here before you do some damage!

alcazar

iTrader: (2)

As above, drain and refill properly, do a search on here for how to, I've posted it a few times. THERE IS NO KNOWN WAY TO BLEED IT!!

Mine runs 84 deg all day, once reached 94 after a high speed run, but in normal driving, town or country, the thermostat should hold it at 84 deg.

yabbadoo4

iTrader: (8)

thanks for your help lads. ordered a new cap as the new one doesnt seem to open the secondary little valve underneath the cap it seems jammed and doesnt open. did a bit of googling and it seems to be a common fault. if that doesnt work then i will try alcazars method. the garage i use didnt use that procedure even though they are a subaru specialist. i assume i can catch and reuse the coolant? it was fresh from the change on sat. could i put the cap in some water and heat it to see if the cap opens?

alcazar

iTrader: (2)

That's for thermostats, the cap opens under pressure....but yours won't have as you had negative pressure, prob due to the airlock.

yabbadoo4

iTrader: (8)

ah right yeah that makes sense. looks like your filling method is the way to go. im away to pick up a new rad cap this afternoon so will fit it and see if that does anything first. thanks for the great info bud.

alcazar

iTrader: (2)

Happy to help. No fun and games until it's fixed: you risk doing the headgaskets a disservice.

yabbadoo4

iTrader: (8)

just a little update on this. swapped out the rad cap and it seems to be fine! when the garage did the coolant change they swapped out my original cap as the rubber was perished but i noticed they had used the round type without the 2 lugs like the ones found on the actual radiator itself. when i checked this cap the secondary pressure seal was solid and did not press back on its spring to release the pressure like a normal cap would. went for a good hour and a half drive with some spirited pulls along the way to get her up to temp then checked this morning on the school run and the top hose was fine with no kinks or flattening at all. sometimes the simplest things eh?? big thanks to you alcazar and the other guys for your advice as the car is in with andy forrest tomorrow for another map and i was worried this was going to spoil my day!