Forester STI bhp
Discussion
The piston issue was a more recent thing and was around the time of the 07 hatchback , it happened as the Pistons were re designed for economy and emissions , there is no evidence it effected cars before then , the cars fitted with the engine were Imprezas , if people were getting failures it was poor tunes too much power or some thing on those lines , it does not effect the Fsti , my friend had a spec D Impreza with it was just before 07 he had piston problems but never found out what it did not appear to be chocolate ones , but as above fsti was never fitted with chocolate Pistons that was Subaru making a really really bad decision a few years later and denying all knowledge
tonyb1968 said:
The "chocolate" pistons are in all the EJ257 engines, its also not a specific JDM engine, unlike say the twin scroll unit which is still the only 2ltr EJ engine that the latest JDM STI uses 
This means it can and does suffer exactly the same fate as this is the same engine they put in to the EU/US market cars but not pushed as much (as are the auto version JDM 2.5ltr impreza's).
HG's were mainly the 06/07 cars, they "corrected" this (supposedly) on the hatch back...
Engine oil pick up pipe, no idea why they moved it compared to the 2ltr engines but it wasn't a great idea and causes issues
As you state, ej257 engine with the problems. Forester STI has the ej255 engine. This means it can and does suffer exactly the same fate as this is the same engine they put in to the EU/US market cars but not pushed as much (as are the auto version JDM 2.5ltr impreza's).
HG's were mainly the 06/07 cars, they "corrected" this (supposedly) on the hatch back...
Engine oil pick up pipe, no idea why they moved it compared to the 2ltr engines but it wasn't a great idea and causes issues
MDMA . said:
FSTI is the ej255 engine.
I apologise, you are correct, but it still suffers the same issues as the ej257 engine, cast piston design and failings in the bottom end, which both share, plus larger bores in a block the same size as an ej20 are its downfall.It still suffers oil pick up issues, HG issues and ringland failure, plus cracking between the bores.
On the plus side, its not as tuned as the Impreza STI but it is more tuned than the wrx 2.5 which do to a lesser degree suffer ringland issues if pushed too far.
WMS have had a few FSTI's in with ringland failure so it does happen.
The newer pistons are more prone to failure and the newer Pistons were 2007 ish onwards , if the engine is tuned maybe too much boost on standard Pistons then yes you stand a chance of more issues , the forester engine with the standard turbo is good for around 330 brake , more than that and a greater chance of failure , I would always worry about buying a 2007 plus car due to the piston change and the main faults are the newer Pistons , at 93,000 miles and a remap plus a track day the Pistons were fine , I went forged as the engine was out , the fsti failures are low , there is always a risk of failure in any turbo car especially if tuned , yes crank bearings can wear that can be a not warning it up and service issue making it worse , I've heard a reason for piston failure on the newer cars was the swap from closed to open loop delay and this is causing leaning and det which is why Subaru did a re hash on the Ecu , arp head bolts and cosworth gaskets are a good idea , better crank bearings , there are loads of subarus out there with no issues , the engines are not weak they produce loads of power for there size , they have a few areas of improvement , another mention I saw was flooring it at lower revs can increase the chance of knock too , but labouring the point the main issue was Subaru changing Pistons 2007 onwards due to emissions and economy
i think a lot of people see 2.5 engine and think load of crap. this is just not true. yes, there have been issues but show me a turbo engine that hasn't . a well mainted FSTI can be a very reliable car. maintenance should be higher than a normal, non turbo car and by that I mean regular, high quality oil and genuine filters ( 3-5k miles for both ). warmed up correctly, cooled down correctly and just as important, the correct anti-freeze / water mix. distilled water is the best for the radiator and block.
I know quite a few people with FSTI's and ISTI's and not one of them has had any issues. infact, I don't know anyone who has had problems. lots on-line but mainly the latter, hatch onwards cars. google any engine and you will find hundreds of problems about them ( VAG group / Ford would probably be the highest ).
I know quite a few people with FSTI's and ISTI's and not one of them has had any issues. infact, I don't know anyone who has had problems. lots on-line but mainly the latter, hatch onwards cars. google any engine and you will find hundreds of problems about them ( VAG group / Ford would probably be the highest ).
Good call ont eh coolant ingredients as the water can corrode the HG
My FSTi HG needed replacing so I went for a recon while I was there, although the bores and crank etc bearings looked mint ((67K miles)
Extremely important when buying to look at expansion tank level after boosting (if it fills, then Hg on the way out, level should stay well down)
My FSTi HG needed replacing so I went for a recon while I was there, although the bores and crank etc bearings looked mint ((67K miles)
Extremely important when buying to look at expansion tank level after boosting (if it fills, then Hg on the way out, level should stay well down)
macky17 said:
I'm after a Litchfield car so if anyone is thinking of selling...
Come up for sale every so often. Why not a fresh import and then re-map for UK fuel once landed. Thats all the Litchfield ones were, with added filter and exhaust. Dont use mine very often, but always a nice sight when i open the garage
MDMA . said:
macky17 said:
I'm after a Litchfield car so if anyone is thinking of selling...
Come up for sale every so often. Why not a fresh import and then re-map for UK fuel once landed. Thats all the Litchfield ones were, with added filter and exhaust. Dont use mine very often, but always a nice sight when i open the garage
The not-that-heavy one wore out and was slipping under hard acceleration. As I am a very hairy middle aged man-child who likes to occasionally demonstrate one of the car's party tricks - in this case, the very smart emergency start, an uprated clutch was installed 
For the extra few quid over the standard item and the fact that leg day, at least on the left side is no longer a thing, totally worth it!
For the extra few quid over the standard item and the fact that leg day, at least on the left side is no longer a thing, totally worth it!
MDMA . said:
macky17 said:
I'm after a Litchfield car so if anyone is thinking of selling...
Come up for sale every so often. Why not a fresh import and then re-map for UK fuel once landed. Thats all the Litchfield ones were, with added filter and exhaust. Dont use mine very often, but always a nice sight when i open the garage
macky17 said:
Yeah I know that's an option. I'd just prefer a car with some UK providence and the basic things already done.
If it helps mine was a fresh grade 4 import. Lad i got it from only had it a few months, then bought a MK2 FRS. Soon as it landed he fitted new discs, pads and Goodridge hoses. Gates kevlar timing belt, new rollers and tensioner, Whiteline f+r roll bars, Ultra Racing strut braces with set up.Then had Prodrive sports cat, stainless mid section and Bob Rawle remap.
He spent all that money then wanted a change. It has all the mods done to it that i would have done to a new import, i just saved quite a bit by buying it already done
And here it sits all week
first world problem having multiple vehicles ! 
Edited by MDMA . on Sunday 10th July 22:18
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