b3n

OK so after some progressive driving yesterday I noticed the water temperature starting to rise. I stopped the car and allowed it to cool down before setting off again however there were about 3 or 4 occasions yesterday where the water temp became hot. The oil temp remained at around 90-100 C.

Driving today all appears fine again. The heaters are blowing warm and the temperature gauge appears to be rock solid.

I have checked the expansion tank and there does appear to be an oily residue on the walls of the chamber. Its not made the coolant milky though. I’ve also checked the oil filler cap and this is fine.

I will say that the car is tuned (370 bhp) and is an MY07 hawkeye. Could the caps for the radiator and header tank need to be upgraded? Could it be Head Gasket Failure??

If it is HGF what sort of price will this be for replacement??

Cheers

TonyBurns

iTrader: (3)

The 2.5's can be very prone to hg's going, especially when tuned, if you have not had the coolant changed and the radiator is in good condition then I would say your HG is shot (well you change both when doing it), and cost is around 800-1200 quid, just depends where you go, if it needs machining etc.
Take it to a garage/dealer/speciallist who can do these, also you didnt say if your car is an STI or not?

Tony

b3n

Cheers Tony, yeap car is an STI.

Oh dear it doesn't look good then!!

jobbie

iTrader: (1)

Had similar on mine about a month ago, bugeye wrx, turned out to be air lock.
All fine now.

I had thermostat go last year and that also caused temps to shoot up but lukily when i drove to garage it was ok but changed it anyway. Also had problems with airlock that time too, ended up having to back fill it thru top rad hose and using a pressure pump thingy on header tank.

We all worry about our tuned cars but most times its just the usual simple things. Always start at the beginning when problem solving...it usually the cheap bits first as well.

Goodluck

dunx

iTrader: (3)

How much boost are you running ?

tyler120706

i had a replacement water pump a while back a non subaru part was used and that caused me some right issues when i dropped my collant not long after and mine just over heated and i thought it had major issues i changed everything cos with the pump been new anyone wud rule a problem out with that turned out due to the shape of the fans its was casuing some sort of vortex and not pumping correctley

TonyBurns

iTrader: (3)

You have to remember that the cooling system is pressurised, the only way it gets an airlock is if the coolant has just been replaced or you have an air leak.
Airleaks are mainly caused by HG's going or rads failing, otherwise there is no other way it gets air in there....

Tony

chaffe

iTrader: (1)

are these HG's MLS out of intrest?

14N-FR

iTrader: (3)

I have an 06 Hawkeye STi.

There was an oily residue in my expansion tank. This was the first signs of my headgasket failure which later lead to cracked piston ringlands scoring the bores of my cylinders.

The high water temps were the last thing to happen right before my headgasket let go on the motorway, causing the pistons to overheat, cracking the ringlands and seizing the engine.

I am not trying to worry you, but my advice would be not to drive the car and get a sniffer test done.

Butty

iTrader: (2)

Are there little pieces of what looks like soot floating on the coolant surface or stuck to the underneath of the rad caps?

p.rite.sh

not looking good mate - I had the same issue, when repaired, had it again, but the second time it was engine failure - 4 cracked pistons, one had crumbled and undrivable

b3n

The water in the expansion tank does look dirty and the underside of the cap is grubby. No sooty deposits on the rad cap.

It's booked in tomorrow to have a pressure test to try and diagnose it. Think this might become an excuse to install some stronger internals. What should be on the shopping list?

Pistons
upgraded gaskets
What else. Any pointers would be appreciated, and thanks for all your help so far!!

giz1978

iTrader: (5)

block test it mate then you will know

14N-FR

iTrader: (3)

That exactly my symptoms. I got them to do a blow by test on my cylinders also.

Shopping list can be as long or as short as you like as I found out during my build.

Pistons (Wiesco, Mahle, Cosworth etc)
Con rods (As above really)
Gaskets (Commectic or Cosworth)
Bearings (ACL)
Head studs (ARP)

Thats your main focus, but then you have options of new oil pumps, catch can, induction kit, turbo etc (depending on level of tune).

I have just completed a 450bhp hawkeye build on a MD321T turbo and the list is ever growing......

b3n

Well as suspected it showing the very early signs of Head Gasket Failure. Current thinking is just to upgrade the Head Gasket and Head stud kit. Think it will start to become very expensive if I go for a stroker kit.

Thanks for all the advice. Great as always.

TonyBurns

iTrader: (3)

Why not change the pistons whilst your at it?

Tony

14N-FR

iTrader: (3)

To be honest, I was in the exact same boat as you. I would change the pistons and rods while the engine is out and the strip down is that far on.

You can then save up and add to the build over time.

That was going to be my thinking until I ended up buying everything all at once and returned from offshore after 3 months to a very fast Hawkeye

chaffe

iTrader: (1)

As a bare minimum id be thinking of valve stem seals and new big end shells while the engine is out, just for peace of mind.