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i heard that STi had a problem with their pistons?

6K views 11 replies 4 participants last post by  arcticscythe 
#1 ·
Many of indonesian subaru owner told that their sti suffered problem. And the problem is blown piston. Is it true that STi had that kind of problem?
 
#6 ·
Like what? I push it sometimes.>:D I always thought the ring land thing was a 2.5L thing and not necessarily an STi thing. Regardless, everyone is gonna' spin a bearing, right? Even with a mild tune and the stock turbo at 118,000mi I feel like I'm driving a ticking time bomb.:eek: Right? All I can do is save up a butt load of money and wait for inevitable.Right?:crying:
 
#9 ·
What appropriate upgrade parts are you talking about arcticscythe? I have a 2.0L and that's how I want it to stay. So, I'm not so worried about ringland failure but this bearing thing has me worried.:crying:Just to clarify...Its a rod bearing ,right? So, what happens? Does the rod come disconnected from the crank shaft and slap around sending metal chunks throughout the engine and all related parts? So, A full engine swap is the only fix only for it just to happen again in 150,000mi or less. I love my Subie and I'll do anything to keep it on the road but this sucks.:| Why did I bother getting the timing belt change if the engine is gonna' self destruct in 40.000mi or less anyway?:pity:

Oh well, I guess if I wanted a car that would last forever I'd have gotten a 98-01 Camry or a Corolla with a 5SFE engine in it.:yawn:
 
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#10 ·
Fidrat I cant tell, gimme a sign. / sarcasm/

For op the issue youve come across is more than likley ringland railure where the piston heads cant handle the stress of knock events pushing the primary ring down against the slots on the side of the pistons. they crack and the free pison rings and rough piston edges do all sorts of damage to the cylinder walls. Upgrading pistons for harder forged pistons is a good first step but there is a tradeoff between harder materials that wear on the cylinder walls fater and softer ones that are less forgiving from a knock perspective.
 
#12 ·
Im sorry, I misunderstood, I took your question as sarcasm which it obviously was not. my apologies.

Yes forged pistons and a proper tune are a great place to start, The factory tune as far as I understand on the 2.5l in 20008-2011 was particularly lean near the top of the RPM range and it often caused knock that applied to great a pressure on the stock ring lands. Even with the stock tune. I would suggest tuning conservatively, leaning towards the richer end of the spectrum ( pardon the pun ) and if you have reason to open the engine then replace the stock pistons with a forged alternative.

And I have heard far fewer horror stories of ring land failure in the 2.0 so you should be just fine. Just make sure you get the grenade out of your up-pipe if you are so unlucky as to have one.
 
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