Skip to content
View in the app

A better way to browse. Learn more.

Ultimate Subaru Message Board

A full-screen app on your home screen with push notifications, badges and more.

To install this app on iOS and iPadOS
  1. Tap the Share icon in Safari
  2. Scroll the menu and tap Add to Home Screen.
  3. Tap Add in the top-right corner.
To install this app on Android
  1. Tap the 3-dot menu (⋮) in the top-right corner of the browser.
  2. Tap Add to Home screen or Install app.
  3. Confirm by tapping Install.

Head gasket failure at 24K???

Featured Replies

My Mom's 2002 Outback blew the headgaskets at 24K. She's 75 and doesn't exactly abuse the car.

 

I know head gaskets are a problem, but isn't this a little outrageous? The dealer fixed it under warranty. should this repair last a while? Did they owe her a new engine, or is it OK to just do the head?

 

Thoughts?

Er um, yes its possible given how the HG age and what the failure mode is. Normally i would say no, but this being a subaru with a 2.5L its possible. The problem with this engine (and all similar engines) is that it is an open deck design. The open deck does not fully support the HG. Add to that any tiny air bubbles. Also if one doesnt change the antifreeze regularly it can add to the problem. Cars also age by time, not only by mileage. Good news is once its fixed its fixed. As long as she didnt bake the engine, it should be fine.

I will tell you to get an oil change though. It is a little extra insurance.

 

nipper

2.5's go at any time. if replaced properly it'll be trouble free from here on out. i'd rather have one go out if it'll be replaced under warranty, that's awesome. now you'll have no worries down the road.

The problem with this engine (and all similar engines) is that it is an open deck design. The open deck does not fully support the HG.

 

Huh??? The EJ18, EJ20, and EJ22 all are open-deck designs and do not have the HG issues of the EJ25.

Huh??? The EJ18, EJ20, and EJ22 all are open-deck designs and do not have the HG issues of the EJ25.

 

 

Good point. The 2.5L is basically a bored out 2.2L block. Some would say OVERBORED. There is precious little metal left in the 2.5L engine. For the 2.5L to not blow a head gasket everything has to be done exactly right. There is vitually no margin for error. A Subaru is not a good car for someone who checks the engine by looking through the ignition keyhole.

Subarus are hands-on cars. Either do it youself, or pay someone else, but maintenance can not be ignored with a Subaru. Subaru, reliable if maintained, damned expensive if not.

Killing 2 birds with one stone

 

 

Acording to this they were closed deck till 1995 (and some of them were hybrids) http://www.spdusa.com/turbos.htm And subaru i dont beleive have many differnt block configurations.

http://legacycentral.org/library/literature/deck.htm

 

 

I think this is also the reason you cant turbocharge a non turbo 2.5L

http://www.ttmtechnical.com/engine_building.html

http://www.carsurvey.org/viewcomments_review_61395.html

http://hondaswap.com/general-tech-maintenance/open-deck-closed-deck-64559/ (its a honda site but great pics of what they look like).

 

The other ones had thicker cylinder walls. The 2.5 has thinner walls.

Another interesting read which hints at the 2.5 open deck issues. In 1999 subaru started looking at the issues (hence the coordination of dates for internal HG failures).

 

nipper

Huh??? The EJ18, EJ20, and EJ22 all are open-deck designs and do not have the HG issues of the EJ25.
As a corollary - only the EJ22T was closed-deck until post 1999. At least, afaik.

As Manarius has said, the only fully closed-deck EJ-series engine Subaru has ever sold in the USA is the EJ22T that is in the 91-94 Legacy Turbo. (It is NOT an EJ22G as the SPD website suggests.)

 

The EJ205 that was in the 02-05 WRXs is open-deck. The EJ255 and EJ257, the 2.5 turbo engines, are semi-closed deck.

 

And the EJ25 is NOT a bored-out EJ22. Yes, the bore is larger, but so is the stroke.

As Manarius has said, the only fully closed-deck EJ-series engine Subaru has ever sold in the USA is the EJ22T that is in the 91-94 Legacy Turbo. (It is NOT an EJ22G as the SPD website suggests.)

 

The EJ205 that was in the 02-05 WRXs is open-deck. The EJ255 and EJ257, the 2.5 turbo engines, are semi-closed deck.

 

And the EJ25 is NOT a bored-out EJ22. Yes, the bore is larger, but so is the stroke.

If anything, the EJ22 is closer to the EG33 than it is to the EJ25. The EJ25 was a new design brought in 1996-97.
As Manarius has said, the only fully closed-deck EJ-series engine Subaru has ever sold in the USA is the EJ22T that is in the 91-94 Legacy Turbo. (It is NOT an EJ22G as the SPD website suggests.)

 

The EJ205 that was in the 02-05 WRXs is open-deck. The EJ255 and EJ257, the 2.5 turbo engines, are semi-closed deck.

 

And the EJ25 is NOT a bored-out EJ22. Yes, the bore is larger, but so is the stroke.

 

Never said it was bored out... but bringing up that point and the information ive seen, i wonder if the cylinder walls are the same.

 

nipper

As Manarius has said, the only fully closed-deck EJ-series engine Subaru has ever sold in the USA is the EJ22T that is in the 91-94 Legacy Turbo. (It is NOT an EJ22G as the SPD website suggests.)

 

The EJ205 that was in the 02-05 WRXs is open-deck. The EJ255 and EJ257, the 2.5 turbo engines, are semi-closed deck.

 

And the EJ25 is NOT a bored-out EJ22. Yes, the bore is larger, but so is the stroke.

 

 

 

I thought that the EJ25 was bored and stroked 2.2 and that in order to compensate for the stroking, the piston pin had to be relocated so the piston would not rise above the deck. This resulted in the piston skirts hitting the crank and to compensate for that, they cut the piston skirts down and is the reason for the piston slap that is so common on that engine. I could be wrong though.

Mike

If this is so about head gasket failure. What makes the STi 2.5 any better?

If this is so about head gasket failure. What makes the STi 2.5 any better?
Redesigned headgaskets. Subaru corrected this HG problem as soon as they heard about it by redesigning the HG's, but the cars had already been built and shipped.
Redesigned headgaskets. Subaru corrected this HG problem as soon as they heard about it by redesigning the HG's, but the cars had already been built and shipped.

So when did they finally fix this?

My fathers obw wagon blew them at 34k.

I've seen an STi come in with a blown headgasket.

 

We can sit here and argue over the causes all day long. One person I've talked too says the EJ25 is too big for its britches. It's tough to describe, and I don't remember everything he said, but the bore is basically too big and coupled with the longer stroke, the engine works itself apart in a way. It's not just headgaskets, the bottom ends have issues too. Then I've heard that the head bolts were not torqued properly at the factory on the EJ25s. Then as Manarius mentioned, there's talk of the headgaskets themselves being manufactured improperly.

Please sign in to comment

You will be able to leave a comment after signing in

Sign In Now

Account

Navigation

Search

Search

Configure browser push notifications

Chrome (Android)
  1. Tap the lock icon next to the address bar.
  2. Tap Permissions → Notifications.
  3. Adjust your preference.
Chrome (Desktop)
  1. Click the padlock icon in the address bar.
  2. Select Site settings.
  3. Find Notifications and adjust your preference.