Hi there, bought my first Subaru not so long ago, it's a 57 plate wrx sti type uk widetrack I believe with 90 thou on the clock
Was standard apart from some bc coilovers, I've fitted a panel filter and removed the second cat, fitted prodrive back box to get that Subaru burble.
Been brilliant up until couple of weeks ago where it started to overhead
But only when you give it some therapy, changed the thermostat and was fine for about a week then did the same thing, boiled it's nuts off on the main road,
So currently it's got no stat in at all and it seems to be fine so far

Does anyone have any ideas or did I just have a new stat that didn't work properly?

Cheers for any help

 

Thermostat won't make a difference mate if they fail they fail open, firstly your system is air locked and secondly you've fried your Headgasket as the system is pressurising through boost you need a competent garage to have a look at it to be honest..

 

It's been to one once, the stat was stuck shut and was replaced by them, I thought if a headgasket went they went? I've drove it fine for last week without the stat, once it's upto temp I give it some beans and it was all fine

 

Heads lifting under boost causing overheating
Classic symptom EJ257
Head gasket failing
Piston skirt or crown fail due to high temp
Piston ring failure due to high temp
Air locking
Bores scorched & as far as blocks cracked
The longer you persist in driving / -
At 90k it's done better than the majority
I'd be giving the engine a major overhaul at this point anyway ../ if it was just a air lock
To begin with ( I'm doubtful ) you have more than certainly aggravated 1 or more of the above by driving it & giving it beans

 

if its overheated once and you havent pulled over in time, thats it, gasket gone and probable engine damage. speaking from experience here unfortunately! the car will be driveable but will overheat constantly. telltale sign

 

I shall have to see what happens when I get another stat fitted,
Otherwise it's just headgasket or will it have knackered other stuff aswell?

 

It will be the head gaskets that have failed without a shadow of a doubt.
I have lost count how many 2.5 head gaskets I have replaced over the years,I have done 2 sets this week and they seem to go at any mileage,I have replaced them at as low as 40k miles on a standard wrx driven by an older gentleman to the one I did at the begining of the week which was a 111k mile STI.
Still doesn't put me off them tho....my 2006 STI has done 92k miles and driven pretty hard but head gaskets just won't give up...wish they bloody would as it would make me get my **** in to gear to do something with it!