fordrsrickc

iTrader: (5)

Just read 33 pages of 2.5 engine failures thread on here and have to say its very mixed messages and from what I can gather there are people with standard internals where they have run them fine with a decent remap by a good mapper to prevent det, and there is a lot of talk blaming the pistons being weak and also a lot of talk about v-power 95 Ron being put through the 99ron pumps after having their fuel tested which caused meltdown.
I have just bought a 330s 2009 hatchback and I am now curious what map it has so I will be in touch with Subaru soon and I have steered clear of v-power and using tesco momentum for now. I am confused as from what I have read, they are the same engines as the 2.5 hawkeye and ive not read many complaints about the hawkeye engines going pop, which leads me to believe it must be down to the map on the hatch versions possibly to keep emissions down etc.
The pistons surely do go pop first as they are the closest component to the built up energy of a detonation where the piston is being pushed up the bore and the built up detonation pushing down the sides of the piston.
So I am now officially confused on what to believe and as I have only just bought the car for £16k my funds are now limited so if I go and have forged pistons fitted when the issue is the map,.surely any pistons forged or otherwise would not be able to withstand the damage that can be caused with det
Is the best option for me to have a map done to run on tesco momentum with my standard internals by a good mapper if so whom would you recommend
Any opinions to help sort the muddle I have created in my head after reading 33pages of the engine failure thread would be greatly appreciated lol
I don't for one minute regret buying my 330s as I love it and still went out to buy it regardless of these horror stories and as regards oil checks and regular service intervals I never miss a one and regularly check my levels etc this is my second Subaru. my first was a JDM twin scroll STI 2003 V-Limited which was bullet proof

fordrsrickc

iTrader: (5)

So is it the map?
Is it the pistons?
Is it low oil?
Is it the fuel used?
No wonder Subaru won't admit fault when there's so much speculation or deciding factors.
Is there a proven result to categorically say the pistons are ultimately at fault?

chopperman

Out of the 33 pages, any idea how many individual cars are identified as failing?

I think if you keep it more or less standard and have the revised subaru map or a bespoke map by a good mapper you reduce the risk. It can be a bit hit and miss when it comes to the standard pistons. as some have gone pop in standard form where as other tuned engines have lasted.
If you can afford to have forged pistons fitted then do it. They are far stronger then the standard cast pistons. As for V-power, it is a good fuel and buying 95 from the v-power pump is not common at all.

Fonzey

iTrader: (5)

There are plenty of Hawk's going pop/gone pop.

fordrsrickc

iTrader: (5)

Apologies for posting this thread separately rather than posting it in the 2.5 engine failure thread,. It's just I am trying to get a more simplified and definitive answer or proof on the speculation where others like me can be saved from having to read 33 pages long lol and still being confused.
The reason I mentioned could fuel be the fault is there is talk of having the fuel checked from the 99ron v power pump for it only to be 95 which is scary to think we are being ripped off let alone the damage to our pride and joys
It's interesting to hear people's opinions and I would love to hear an opinion of a very good mapper and see what he thinks and may put my mind at ease. thank you in advance for any responses

chopperman

There can be several different reasons for ring land fractures. Could be det due to low octane fuel, could be a poor map,bad modifications or modifications that have pushed the engine beyond its design brief. I can even be poor piston installation. If your using standard pistons its best to stay clear of the rev red-line but you dont need to rev high to drive a 2.5 quickly. I believe the problem map was due to the aggressive fuel cut at the rev limit. I think the revised map altered this fuel cut and lowered the rev limit.
Any main dealer will be able to tell you whether your car has had the re-call map installed.

chopperman

Are going pop? Did your crystal ball tell you that ?

DeweyAXD

Best bet imo is to talk to a couple of reputeable engine builders/impreza experts. Opinions on here differ so wildly, some based on personal experience (both good and bad), some based on hearsay. Time better spent on the phone doing that than on here hoping to find a definitive answer that i fear really doesn't exist.

tubbytommy

iTrader: (20)

there sh1te
the end...........................

tubbytommy

iTrader: (20)

its actually a genuine opinion, in standard form the 2.5 is crap and the fail all too often

fordrsrickc

iTrader: (5)

Hence the reason for my post my question is,. Is it the fuel or pistons or mapping issue or low oil ect,. You're quite right they have failed and is it that the engine is as you say CRAP or is it any of the latter,. If you know the answer to the thread you will be able to settle a 33 page debate which has had some professional opinions from engine builders, mappers, and people with very extensive knowledge of engines and their characteristics,. But I'm sure you're scientific approach of they're just crap will settle the debate.

Tomwrx

iTrader: (54)

The usual 2.5 haters comments, more hatches have went pop than hawks
but thats due to the crap ppp map and why they were recalled.

U will mever get a true figure, plenty other models have went bang but folk might prefer not to post about it on here and only use there local forum or not even be on forums.

More blobs have went bang due to pick upipe failures if u go by forum info,

tubbytommy

iTrader: (20)

ive no idea why its crap, but it is a well documented fact on here and many other subaru forums that its a weak engine and this is confirmed by many tuners/builders.

but when rebuilt with forged pistons etc is a very good engine.

53

iTrader: (41)

No point in owning a Subaru that you can't drive to it's full potential. Take it easy, be carefull etc etc etc... it's a feckin 30k sports car ffs it should be capable of all the abuse you can throw at it on the road and track. Lol my 18 year old classic with it's original 2ltr engine doesn't wimp out at the first sign of a redline or decat pipe. Fact is the 2.5's are a punt standard or otherwise, and if you're going to have to forge it for piece of mind you're better off investing in a JDM model or crafting something yourself from a better looking model

chopperman

Very true and i think i have read more threads on big end / main bearing falure on 2L engines on forums than 2.5's going pop. maybe thats due to age or the fact far more were sold.
The 2.5 is a great engine for a fast road car with amazing low down torque and driverbility. The engines that have failed point to two weaknesses. The first being head gaskets leaking under boost. More common on 2006 cars with the pre revision gasket. The second weakness is piston ring land fracture. This appeared to be more common in the hatch cars and prompted subaru to re-call and install a revised map. Funny thing is it always seems to be #2 or #4 piston that cracks. The hatch also had an issue with the oil pick up cracking.
There is a lot of paranoia about these engines and a lot of people re-posting opinion and hearsay rather than fact and experience on forums. This makes it appear the problem is far more common than it actually is.

Tubbytommy is correct when he says "but when rebuilt with forged pistons etc is a very good engine".
Generally a set of quality 11mm head studs, cosworth stopper head gaskets and a set of forged pistons fixes these engines permanently and give scope to tune for more power.

I am speaking from experience as i cracked #2 and #4. I had mine forged and it is now a great car . Mine was running 360bhp when it let go.

staccato

One thing to consider is are forged pistons a cure? Lets say for example an engine fails maybe due to fuel cut (speculation over the ppp map) or detonation.

Now the car goes into the workshop and has forged pistons installed. It's very very unlikely that the car will leave with an original map. If the engine has been rebuilt at a tuning company its highly likely that a bespoke map is going to be included as part of the work, so technically how do you know what the cure was?

Say the car now runs fine for years with no failures. Was it the map or was it the forged internals that cured the issue?

There seems to be some people who had failures as low as 3k miles, had the internals replaced at subaru under warranty and then had exact same failures 3k miles later on. Presumably that's because subaru replaced the only 'failed' parts and didn't alter or correct the cause of the failures - the map.

Most people who were out of warranty at the time of their failures and went to a tuner for the repair work, and most of which would have had a bespoke map done at the same time do not generally report any further failures.

My 2008 hatch has a sports catted downpipe, prodrive cat back and a slowboy racing remap which was done at about 12,000 miles. In the last 5 months of mixed driving I've not had any symptoms and haven't even needed to top up the oil so I'm keeping my fingers very much crossed that these failures are map related and I have an excellent remap.

Anyway just one thing I noticed in reading so much over the past year.

jazzyjembreaze

iTrader: (11)

We will get another 33 pages out of this thread & still end up back at the start
Best thing for the OP is too drive his car enjoy it
Delete this & the other thread from his head ....
You may never need to come back to post on it
But if you do / we will all know then

It failed

lordharding

iTrader: (1)

To throw a spanner on the works / chocolate pistons
The 330s was 32 k new
Like many other people that purchased the new hatch / STi at big money
The engines should have been good for 100k miles
Subaru should have the confidence to offer a 5 year warrenty on a expensive
Car
It would be intersting to see on case law if a owner took dealer / Subaru to court
Under the sales of goods act
I'm sure the judge would favour the consumer over the manufacture

staccato

What was your spec - mods and mapping etc?

Alan Jeffery

The issues with these engines are the same ones suffered by Sierra Cosworth owners going back into the eighties. People can't leave them alone! When you have a car that has so much tuning potential, you naturally, being petrol heads and all, want to tune it. It's no good blaming Subaru if it's been messed with at all. Warranties are generally being rejected because something has been changed or "tweaked" after it left the factory. Certainly all the ones we've seen, and we've had a few recovered here with stripped engines when Subaru said "no way" that have been got at by somebody else, so fair cop guv.
Having said that, I don't know anybody on this forum who would want to leave their car with stacks of untapped potential. So what's to be done?
Fix the main areas of difficulty is what. Head gaskets and pistons are the flies in the tuning ointment, so ditch them, and build the engine up relative to your turbo ambitions. 400bhp is fine on stock rods, but as the big deal cost wise is stripping the thing in the first place, you might as well fit forged items. We use Cosworth head gaskets with ARP head studs. Mahle pistons are very good, there are others of course.
I'd say anyone with a car still under warranty has to either trust in the knowledge that the completely stock vehicle they are driving will be covered under warranty, or make sure they have savings put back to fix it properly if it breaks.
Believe me, Subaru are by no means the worst to deal with when it comes to warranty issues. If you don't believe me, buy a Nissan!

staccato

The difficulty is standard cars have suffered the same failure, cars with subaru's own endorsed ppp pack have failed, and modified cars have also failed. I know what you mean - if you modify its your own tough luck but subaru's tolerance in this 2.5 engine doesn't even allow for its standard power, or the ppp power by the looks of it. Subaru are also not stupid. How many sti's that they have sold over the years do you think remain unmodified? How many purchases have been made probably due to the fact that they used to respond so well to modifications. Yet they build a new engine with seemingly 0% tolerance? It sounds simply like a manufacturing or design error.

It's very difficult to lay a finger on exactly what's going on. Owner neglect is hard to identify as understandably many want to attempt to push it through under warranty so th truth may not be exposed. But the same part failing repeatedly on different cars is more than coincidence I'd say

Alan Jeffery

It looked to us that there were several departments who weren't talking to each other.
The piston people didn't want a forged one on either cost, noise, or other undefined grounds.
Whoever was responsible for head gaskets didn't ask the engine people to tighten the bolts up properly.
The engine management team had a brief to reduce emissions and fuel consumption, which didn't suit either of the above design wise!
What do you get when you add that up?

Bob Rawle

Subaru were taken to court over it in the USA which is why they revised the 2010 on engine specs. Small motorsport company sued under trade description, they were rallying with stock engines and, of course, they kept breaking them. Subaru said the cars were being used out of application, the company pointed to all the rally orientated advertising blurb, court found in favour.

cheers

bob

AS Performance

iTrader: (4)

bearing in mind that Subaru have had 2.5 head gaskets problems right back to when they first introduced over-sized blocks into the older Legacy 4cam (2.5 naturally aspirated) then its not exactly suprising they suffer the same with twice the power................

this helps

https://www.facebook.com/photo.php?f...type=3&theater

rob84

iTrader: (5)

your CDB inserts, what costs are these Alyn ??

Pez

It does seem very hit or miss. I spoke to Iain Litchfield and he said their first tuned sti hawk was ragged on stock internals for 20k without issue. Then their next one done less than 3k before it went pop!
I know the hawks also suffered with oil pick up pipes failing and that's goodbye engine
Mine is tuned far beyond what it was meant to do, being a UK model and then mapped by Bob, it's running around the 400bhp mark and has been like it since virtually brand new (I brought the car on 860miles!) It's now on 20,400 and touch wood is still going ok. Sitting time bomb maybe but I'll cross that bridge when I get to it.
Personally I believe a lot of it also has to do with how you look after it as well.

AS Performance

iTrader: (4)

yes Rob, fully machined and inserted they are £600inc./pair - only pita unless your starting from fresh is the need to be bare casings for us to work with but we can undertake the strip/rebuild if required (at extra cost)

another

stonejedi

iTrader: (51)

That looks like its ready to take some real power.SJ.

salsa-king

my 330s is running on either Tesco Momentum or V-Power, I wouldn't run on 95 octane, from a warranty point of view.

so far my car is ok.... still have 11 months warranty left too.

Serviced when it is due at subaru dealer.

If there was an issue I wouldn't be very happy when when I've followed the rules.

I'm now on 23k miles

fordrsrickc

iTrader: (5)

Thank you to all for their advice, my mind is now at ease and I have been in touch with reputable engine builders inc Scoobyclinic, Roger Clark and API and have qoutes from a few for work to be done forging the pistons inc cosworth gaskets etc. but I can't have the work done until after my wedding in November
As I wasn't supposed to buying the car until after the wedding so asking to spend another up to £5k won't go down very well with the missus. So I hope my ticking time bomb holds out until then fingers and toes crossed lol.
I'm having an issue with the keyless entry system not working two days after I collected the car it just stopped working and I have to press the unlock on the fob,. The interior light comes on when I approach the car and the boot works on the entry system but not the doors.
I have also noticed a keypad under the flap on the right side under the mirror controls like an immobiliser type keypad and haven't a clue what it's for I have trawled the web on the keyless entry system and on here but can't find a solution to the problem and it says in the manual that the doors should lock automatically after 30 seconds if I forgot to lock it and that's not working also,. any ideas would be appreciated