hello all

Took the car on a Dyno a couple of weeks ago for a map. on the last run quite a bit of water started coming out of the overflow witch caused a airlock. I bled it and got all the air out (nightmare) its running fine now but anyone got any ideas why this would have happened ? and what I should upgrade or do to prevent it happening again ?

Don't no if this will helps

Waterpump changed before Dyno

engine -- EJ20closedeck (original internals done 30,000miles that I no about)

Bhp -- 305.4

Coolant used - Titan / Silkolene Pro Cool Antifreeze

appreciate any advice

 

you mean the expansion tank?

 

think so its written in Japanese on my car so cant tell what the lid says, its a 93wrx its the bit in front of my battery that connects to the side of my rad. it got a yellow lid with a L-shape nozzle thing sticking out

 

Tbh it doesnt sound promising if you have not recently bled the cooling system, even with the top off the water on a bled system should not flow out, this would indicate you are getting a leak into the cooling system somewhere.
Bottom line is you have a failing head gasket which is showing under pressure or if you are lucky it may just be a pipe that has gone hard and split and also is sucking in air.
I would get the car checked out by a decent subaru mechanic sooner rather than later.

 

edit.

car has blown headgasket.............

 

Could be head gasket.... But you changed water pump before the run? So perhaps there was an airlock after that and the dyno run blew it out? It's not unusual for coolant to flow past the header tank cap into the overflow tank (hidden in the wing with a filler cap visibly by the batter. Then as the car cools the coolant should be sucked back in to some extent. Get it sniff tested.

 

Not initially but as the coolant heats up the level will rise and it will **** out without the cap on. That's why the cap is spring loaded to only open at the max pressure.

 

Its under pressure with the cap on, if the cap isnt on then its not under pressure but I know what you mean, water heats up etc

 

I know... That's why I didn't say it was under pressure with the cap off. I said the level rises. I just wouldn't think it's game over quite yet until it's properly checked. The amount of times I have thought things were going to die due to reading horror stories then found in my case it was just a random thing that went away or was easily fixed. Worth checking out tho!

 

Thanks for the replys everyone appreciate it.

So most people thinkin headgasket. The car runs perfect sins I bled it and befor the dyno it was running good I don't seem to be losing any coolant or oil and no misfire the car seems to be running better then ever so can it still be HG problems with no symptoms ?