Project Import: Subaru EJ25 STi Piston Ringland Failure Breakdown

[BigZdubZ]

wow

[cmunch77]

Thanks for the video. My stock 08 Outback XT has a crack piston ringland at 85k miles last month. It did some damage to the cylinder head also.

[urmomisfineinbed]

it's sad that this is so common most of the other parts in the STI are so high quality.

[alabaska182]

If we get aftermarket pistons would it solve the common ringland failure with the OEM pistons? If it does, what sort of pistons would you recommend buying if you live in (me Canada) when it gets cold and hot? I would be interested in getting some new ones for my 04 sti. Thanks for the video.

[Projectimportcom]

@alabaska182 Replacing the pistons solves the issue. Block would need to be bored and honed to get true sizing, then purchase correct size pistons based off that. As far as extreme hot and cold temperatures, not too sure. Being in southern california we dont run into that issue. Normally we use either JE or CP pistons. To answer your temperature question, I would contact piston manufacturer and talk to tech.

[akotr3mor]

@Projectimportcom just a minor correction, going aftermarket such as forged which seems to be the popular vote these days may avoid ringland issues but you'd still be running on stock rods, so it's a very expensive temporary hold back...I've heard AOS seem to help the most seeing as it prevents the oil from leaking in during WOT

[Projectimportcom]

@akotr3mor Air/Oil Separator may have helped. doing oil changes on time before oil broke down may of helped. using a high quality oil may have helped. using a better oil filter to clean oil may have helped. maybe the tuning was off. maybe the car had a dirty maf. maybe the front 02 sensor war failing due to age. we could go on with things that may of extended the life of the ring lands. only one thing for sure they fail.