Hi there.

I have a 2006 STI spec D impreza with PPP and I am having exactly the same problems.
The car has been fine since I bought it 3 months ago (done 4-5,000 miles in it trouble free), but recently the temperature (although very rarely) rises to the 2/3 mark when previously it only rose to the 1/3 mark.
This is normally after 'sprirted' driving and soon returns to normal (1/3mark) within a few minutes.
This only seemed to happen if I was driving hard before stopping in traffic. It always returned to normal temp very quickly.
However, yesterday I was out for a blast and came across a massive traffic jam which didn't move at all (car crash in front) the temperature just kept getting higher until it was near the red section.
I decided to turn the car off and wait for it to cool down. A few minutes later steam came out from under the bonnet (looks like it came from the coolant overflow)
I waited 1/2 hour for the engine to cool and checked the coolant level then started it up.
It started first time as normal, with no white smoke or anything, and drove it ten miles home.
The temperature just stayed as normal (1/3 mark) and I got home fine with no loss of power, smoke or anything.
I got up this morning and checked the coolant level and it was below minimum with an oily residue in it. This residue was all over the sides of the reservoir and on top of the coolant.
I phoned in work and told them I was not coming in and drove it to the garage (just round the corner) to let them have a look at it in fear of the engine seizing on me.
They are doing checks on it now.

What do you think it is? (thermostat, airlock, radiator, gaskets?)
What is this oil in the coolant? (Is it engine oil? residue the coolant leaves behind?)
STIMAV, did you get it fixed? any updates?

If anyone could shed some light on this I would really appreciate it as I love this car but I don't have the skills necessary to do the repairs myself and don't want to get ripped off paying for a headgasket repair when it only needs a radiator or thermostat.

It is a 2006 34,000 miles UK spec D WRX STI SPEC D PPP with full subaru service history. It's last one was done at 29,000 miles.

Please help.

EDIT: I too have the water wooshing noise from behind the dash too but my old 03 wrx had that too.
There is no coolant in the oil and no gunk under the oil cap etc BTW

If its definitely oil in the water then bad news.
The temp only getting to the 1/3rd mark is a little odd - it should have risen to almost the 1/2 mark when fully warmed.

Check its definitely oil.
Check for exhaust gases in the coolant.
Bleed the system properly (can be a real pig) and drive off boost to see if the problem carries on.
When the temp starts to rise, jump out and feel the radiator. I found mine was cold (fans were on a long time & bowing cold air) when this happened and cured it with a new thermostat.

Subaru have had my car in and done a series of checks including checking for exhaust gases in the coolant and they havn't been able to find anything wrong with mine what so ever.

The odd thing with mine is that it seems to be becomming more and more random. I had a quick blast on Sat against a new Focus RS, nothing more than 5 mins or so's worth of fun - but that seemed to be enough to push up my temps once I got back into town and into traffic - the needle was peaking to the 2/3 mark and then dropping down very quickly. Then Sunday I took the car on a longer run - pretty much off boost the whole time (family in the car) and nothing at all. Temp gague didnt budge.

The general concensus opinion on mine is that the thermostat is sticking and this along with a slight block in the coolant system was the likely problem.

I've actually just taken delivery of a Zero/Sports cool running thermostat and have spoken to a Scooby specialist about fully draining the cooling system and then refilling from scratch. This is all being done on Monday 30th Nov - so I will know more then.

Thanks for the replys.
The garage have just phoned and informed me it's a headgasket.
Exhaust gas was found in the coolant which they said could mean nothing else.
They are taking it apart tomorrow and are going to skim the head and fit a new gasket(s)
they have quoted me £500-£600. Does this sound right/price sound right?
Is there anything else I should get them to do while the engne is in bits?
This car does burn a lot of oil. Not visible consumption though, no smoke out of the exhaust or anything. It just needs topping up a lot more than my 03 wrx used to. That car burned oil too.

Is this oil burning normal?
I love this car bu. I'm starting to get that horrible 'i don't trust my car feeling'
are these guys blowing smoke up my ass or does exhaust gas in the coolant mean a knackered gasket?
Thanks a lot

My understanding was that Headgasket jobs were £1000-£3000 depending on the severity and where you took it ??

I don't know where you were quoted that but i've had headgaskets on other cars replaced for £400 before. This isn't at a Subaru garage. It's one near me as I didn't dare drive it any furthur. I take all my cars to this garage apart from for services.
Maybe it's because I live in the north so the prices are lower.
I'm getting worried now! They said they'll know exactly what's wrong when they take it apart tomorrow.
Does it sound like a gasket to you?

On other engines it isnt an engine out job - the subaru requires the engine out for headgasket change. So that price you have been quoted is very cheap IMO.

Just as a matter of interest, according to my PSi3 unit the general running temp. is in the range of 86 - 97c With the fan cutting in at 96c The dash gauge never seems to move from it's centre spot. 03 STi

JohnD

The gauge is so heavily damped it is next to useless.

The 2/3 value on the gauge is actually about 120C - not where you would want it to be.

Most of the time on mine it is on the 1/3 mark.

I am and have always been convinced that Mavs is thermostat but not so sure on TheDuke - the oiley residue does point to headgasket ...

Any further communication from the garage Duke ??

Very similar to mine, although mine sits at a 1/3. Never tops 95 on my monitor and I have a standard thermostat atm until it's next service.

Exhaust gas in the coolant is an HG problem.
Presumably its a warranty job if its happened after 3 months?

Yea I can't get hold of the garage I bought it from. Looks like it went under, all phone numbers don't work and they have no cars on their website. Looks like I'm paying it myself but I'll keep trying. :(
I just phoned up the garage and they said they have the engine out and are going to strip it tomorrow.
I'll keep you posted.
How much oil does everyone else use? I use shell helix ultra. Is that any good?

Duke - Just FYI, I've been speaking to Torque of the Devil who are based in Uxbridge and do alot of work with Imprezas. I asked him for a rough idea of what the costs involved would be if mine did turn out to be a head gasket and he quoted me a rough cost of £1000 which is actually a lot better than I was expecting.

I should be able to get mine done under the RAC Gold warranty if it needs to be done - just hoping if that is the case I'll be able to "hide" the cost of a cat back exhaust system in there as well :norty:

Obviously hoping that mine's not a HG problem but I'm preparing for the worst.......

Well I'm just worried that the headgasket is the affect of the problem and not the source.
They are taking the head off now and will let me know what they find. I just popped in to drop the oil off I want in it.
What a nightmare.
The warranty people say that they can't do anything without a policy number and I can't get hold of the garage I bought it from.
I hope to god this doesn't cost any more than quoted as I'm already going to have a skint Christmas as it is. Never mind if the price goes up.
Is there a way of telling if the car is running more power than it's supposed to with paying loads to stick it on a rolling road?
My friends reckon it's running more power than 316bhp and I did take a spec d out with no ppp that didn't feel much faster than my old wrx.
Maybe if it's running more power than it should the cooling system is crapping out.
I think I'm just getting paranoid now. But if th garage phones up saying the heads cracked or a pistons knackered I don't know what ill do.
It wasn't blowing smoke or lost any power though so hopefully it'll 'just' be the gasket.
The garage mentioned that here might be stronger head gaskets available. I've heard the standard Subaru sti ones are good but was wondering if anyone has any recommendations. I don't mind payng a little more for a different gasket if it's goig to help prevent this from happening in the future.
I don't track or race or anything. I just drive to work and have the occasional blast.
Thanks

From what I am told and read head gasket failures on the 2.5's are getting more and more common all the time.

Not true Mav.

Good to know as a Hawkeye owner, just seems to be posts of a similar nature all over the place........

And on most of them there are people scaremongering. The head gaskets on your hawkeye are no more likely to fail than any other really unless you start taking huge liberties with boost levels. Most of the overheating issues I have seen on hawkeyes (including my own) relate to thermostat sticking. There have been some go for sure but you will always get people saying oh yeah mine went and then it gets sunk into scoobynet myth much like the STD blocks can't take more than 450bhp rubbish that is now thankfully being disproven all over the place.

Just do your thermostat like I suggested nearly a month ago ;) and your particular issue will go away I am convinced ( as the symptoms are exactly as I experienced)

hi i am having the exactly the same problem with my 340bhp/350lbsft 56 reg sti, but the only thing is im getting black oily stuff in my coolant. i have had a pressure test done on both cooling system and cylinders. They both came back ok. now the only problem i have found is a crack about 25mm long in my turbo coming from the waste gate, this was discovered when changing my exhaust, this problem only started since the exhaust was up graded. does anyone think this could be the problem????? I am wating for a new turbo to arrive so will keep you all up dated.

Heard of a few VF43's cracking. I know of one with cracked VF43 and headgasket failure. By no means common, but it does happen.

Cheers fella appreciate the comments. All being done on Monday and I have my fingers crossed your 100% right :thumb:

I had the same black stuff. A sort of granular rubbery substance or rubberised paper. Could never figure out what it was in truth lol. Coolant swap and thermostat change and fine and dandy for 25000 miles after til I took the engine out and swapped for forged build to up the power.

Have heard of a few vf43 turbos crack when run at higher boost and temps.

You were running 1.6/7 weren't you dunc originally back in 06/07 ?

Bar ?

Was 1.5 at it's peak on the original engine and turbo with no I'll effects.

With the crack in the turbo do you think it could be putting oil into the cooling system?? or do you think im clutching at straws?? This is my first subaru and first turbo car so im still new to all this. i think i want my lotus sunbeam back.....

I was misinformed then, I am only running 1.4 bar on mine, got bored of overboosting all the bladdy time !:rolleyes:

The ecu can't see over 1.55 ish so has trouble controlling it.

You should be able to run a bit more than that ;)

*thread stolen*

So what should an 2.5 STI with PPP boost to ?? When I had my STI rolling roaded a few weeks back it was boosting to 1.45bar - and as far as I'm aware it's totally standard (other than the PPP of course).

It's not stolen we're just looking after it till the 30th;):D