Hi all

I wondered if anyone had any thoughts as I'm all out of ideas. I have a 2006 Hawkeye WRX Wagon with 58,000 on the clock - lightly modified with a Powerstation Remap (280hp) and Miltek Exhaust with Sports Cat.

It had an intermittent fault some time about 6 months ago where after an hour or so of driving the engine temp would begin to creep up. The car got to normal operating temp and stayed there and sometimes, after an hour or so of driving, the engine temp would creep up.

It then had to be allowed to cool down, and it would function normally again - getting up to normal operating temp and staying there.

It happened roughly half of the time so I replaced the radiator with a Mishimoto item and bled/replaced the coolant - which didn't help. I tested the new setup and coolant was flowing as it should, and the thermostat appeared to be working normally.

Despite this, I figured the fault was with the thermostat and replaced it with an OEM one. The one that was removed had a slight 'groove' in it, indicating that perhaps something was stopping it opening fully after the car heated up. Anyway the new thermostat resolved the issue entirely for about 2 months - car would get to normal operating temp and stay there for any amount of time.

All of a sudden, last night, driving home the temperature creeps up again and I'm out of ideas - coolant level is good, can't smell anything in the bottle, no leaks, nothing to indicate a head gasket...and I'm out of ideas!

So any help/advice you can provide and I'll be incredibly grateful!

James

 

head gasket is failing, the 2.5 engines usually do

 

The head bolts stretching under boost allows air into the water cooling system.

It will eventually cause a big enough air lock to loose the heaters and cause you to over heat. You need the coolant checked for hydro carbons bit sadly your on a slipper slope to spending over a grand.

The fix is updated head bolts, cosworth head gaskets, engine out I'm afraid.

When I had mine done I took the opertunity to have the clutch changed too.

Some will say do pistons, bearings and forge it. But that will see you close to 3k but will mean it's safe for over 400 bhp. I just did the basic and the cars still going strong

Hth

Jake

 

Thanks - yeh I'm thinking it's the HG now - i just wondered if maybe it might be worth trying a new water pump first - in case this is somehow affecting the thermostat?

Not sure that's even possible but the car still drives perfectly until it overheats.

Has anyone here had experience of a bad HG? Did it affect the car's performance noticeably?

James

 

Yes as above lol. You can drive the car like a granny till the cows come home.

It's sustar high boost that causes the air lock.

I to tired to deny it. But it's the hg fella

 

as the others say the HG - BUT it could also be an air lock in the Coolant System, which would need flushing and slowing filling back in (plenty of step by steps on youtube)...

i would get a sniff test at a reputable garage also

But don't panic on the HG just yet - ive had lots of panics off this site when it was simple fixes (thank the lord)

 

Doubt its an airlock, would be constant, get a HG sniffer check done to find out.

 

Any tell tale signs of head gasket corrosion in your overflow bottle / also are the levels fluctuating or overflowing in there ?

 

Thanks so much to all of you that have taken the time to reply.

I am trying to arrange a proper sniffer test and will take it from there.

Fingers crossed, hey? And happy new year

 

Water pumps do not normally fail, if they do and the coolant is passing through the mechanical seal then it will leak externally and you will see it dripping/ dry coolant stain around the stat housing/bottom hose area.

My money would be on early signs of head gasket failure

Mick