Oakleyextreme

Just a quick question if someone could kindly answer.
I've heard a lot about the 2.5 lump having problems in the hatch, just wondering is it the same lump they fitted in the 2011 onwards saloon and if yes have they sorted out the problems

Steve's Sti

iTrader: (2)

I very much doubt they have changed the pistons for the uk market, im pretty sure there has been a few of the newer ones suffered from ringland failure

Oakleyextreme

I have a pro r 320bhp ecu fitted by subaru. Would this be considered ok against ring land failure or doesn't it matter, wondering if the only failures have been when people are asking big bhp out of there cars

Steve's Sti

iTrader: (2)

Mines failed with just the ppp fitted 320hp, mines saw the engine retard ignition heavily now and again but always ran thirsty on oil tho

The Trooper 1815

iTrader: (31)

Nope. Just as prone to sh*t it's guts as any other 2.5 money pit.

scoobyboy1

iTrader: (16)

Got a hawk Sti with the standard 2.5 thats got a full decat, filter, front mount intercooler, remap, etc etc running 377bhp and the car is on 55k miles. Had most of the mods fitted when near new, and the engine seems to be running still strong!!

I bought my car, with the intention of re-building the engine down the line, so waiting for the day when the headgasket goes, im under no illusion that it will last for ever or it wont go on my car, but got a fund set a side for when it does!!

Oakleyextreme

Just don't expect to hear about engine failures on a jap made car. I can understand it if the car has been modified by someone who don't know what they are doing but not out of the box so to speak.
I only have 16000 miles on the clock and only do approx 6000 a year lets hope it last lol.
Before I had a high miler honda S2000 vtec nut revving car and the engine was sweet as the day it left the showroom.

urban

iTrader: (1)

Nope, doesn't matter

Gear Head

iTrader: (2)

Answer is, whilst still in warranty, don't modify it!

Oakleyextreme

The pro r ecu is excepted by Subaru and doesn't effect the warranty. But that doesn't matter as it's ran out.

Gear Head

iTrader: (2)

Then there is nothing you can do unless you want to spend £3-4K on a forged build.
Or just enjoy it until it goes bang.

TheWaterboy

Does this mean all of the Subaru 2.5 engines are fragile? sohc engines as well as the dohc ones. After reading various threads I'm still trying to work out the most problematic. Reading between the lines Sti Hatches seem to be the worse and maybe Hawkeye Stis but it seems the WRX Hawkeyes don't seem to be as bad? Also does a good remap help with the issues with weak pistons?

Markyscoob

Basically the 2.5 is not a competition engine and was never intended to be. Thus they fitted cast pistons and rods rather than the forged ones in 2.0 STi engines. The 2.5EJ uses normal stretch bolt head fasteners too.

What happens is that high boost and cylinder pressures cause the heads to pull up and this pressurises and overheats the car. The gaskets themselves haven't failed, just not clamped properly.

The overheat can weaken the pistons and the thin piece between the rings fails and causes excessive oil consumption and wear in Cylinder 4 usually. Also it pisses coolant out of the overflow bottle.

Putting forged pistons, rods and proper head studs in addresses all of these issues and give a bullet proof lump that will last and handle loads of boost and power....

Oakleyextreme

Cheers markyscoop that gives me a good insight of the problems with the 2.5 rather than people just keep saying made out of chocolate.
I was reading a little bit on a USA sight saying that subaru done a ecu update when cars came in for a service and only use 97 Ron fuel which I do and won't use anything else.

BrownPantsRacing

iTrader: (6)

Does the car get rolling roaded or setup in any way when the Pro-R ECU is fitted? Or is it just fit, turn on and drive?

I always have doubts with any "bolt on" ECU management that is not uniquely tailored (calibrated) to your car's own sensors etc. Could be worse for the engine than a factory map!

To my knowledge, the 2.5 engine internals have not changed from 2006 onwards, only the bolt on bits like turbo's and the ECU map. It's possible 2008-2010 cars were more effected by failure due to the factory map.

Gear Head

iTrader: (2)

But that will not help the fundamental problems with the 2.5 as explained above.

To be honest, I wouldn't worry about it. Life it too short to worry.
Drive it and enjoy it. May be try and pick up a forged short block and stick it in the garage for a rainy day.

All engines go pop at some point fella. If you are worried about such things, the Impreza is the wrong car for you.

BrownPantsRacing

iTrader: (6)

Good advice! As a 2.5 owner I completely agree.

Oakleyextreme

I'm not to worried about it but don't get me wrong I'll be pissed off if it went bang but also be a excuse to make it a bit special. Just so surprised about reading about problems with the 2.5 and just wanted to understand why ( thanks to markyscoop )
I love fast jap cars and think they just a little bit special

lordharding

iTrader: (1)

Think we are missing to points though guys
You spend 25/30k on a car with a quality image like Subaru and you would buy it expecting it to last 100kmiles plus and gave many years of good reliable service just like owners of classics when people bought them in the late nineties it was marketed as ultimate reliability and excellent build quality
Then 2006/7 and the birth of the 2.5 and then followed onto the hatches again people bought them as they knew Subaru made a great product with a great track record from 1992-2006 and want happened

Subaru screws up big time ad how many die heart customers are honestly going to buy another one ?

Steve's Sti

iTrader: (2)

I would buy another albeit cheaper road tax! Thats my only gripe ive forged mines was the best thing ive done as its transformed the car totally new turbo injectors, i dont care that i had to do it as some engines are just terrible from day one others are fine, enjoy it if your worried sell it

The Trooper 1815

iTrader: (31)

https://www.scoobynet.com/scoobynet-...-failures.html

The 2.5 and the attitude of IM will tarnish the Subaru image for some time to come.

fpan

iTrader: (11)

All correct apart from the fact that not all 2.0 have forged pistons

The 320R is not a different ECU but an Ecutek remap.

NormantheDog

So is the Japanese version of the hawk eye and hatch a safer bet than the uk version?

beardo47

Yes, the JDM hawk uses the 2.0 engine (better than the UK 2.0 too)

**jay**

iTrader: (1)

That was the material they cast the pistons from on the 2.5 lol

NormantheDog

And the Japanese Hatch uses?

urban

iTrader: (1)

Yes, but not at 10/20/30K miles they don't.

I'd say to the OP, either flog the car and purchase something else, or forge it now while its still healty

Infected by sti

iTrader: (6)

I beg to differ lol less than 30k on a good friends car before it got upset. She won't rag the **** off it so if it was in someone's hands who likes to give the car grief then god knows when it would have gone.

They are shìt and there is no 2 ways about that imho.

BrownPantsRacing

iTrader: (6)

Even with the issues on the 2.5 which I totally agree have been greatly ignored by Subaru and relatively unsupported losing them customers, I would still buy another one! But... My 2.5 hasn't yet suffered the dreaded failure, if it had I may feel very differently.

Completely agree that a brand new car expecting engine failure and huge rebuild costs at 10, 20, 30k etc is totally unacceptable.

Subaru have let their customers down.

urban

iTrader: (1)

What car was it, and what happened?

Big time