Subaru Outback Forums banner

EJ253 to EZ30 H6 Swap Help

295 Views 8 Replies 4 Participants Last post by  Brucey
Obviously never attempted an engine swap before... just FYI...

I've seen a bunch of people not reccomend putting an EZ30 in an EJ25 model Subaru but why... is it really that much of a headache?Most people want to take the dash out or replace the entire cars wiring loom etc etc, though there's people that haven't done that yet the speedo works fine, just has a 1.5x speed applied to the tacho due to 6 cylinder vs 4 cylinder.

So just to be clear I do have everything I need for this swap as far as I know. I have the ECU, TCM (located on sterring column), key/fob from the EZ30 and the reader on the ignition barrel, 5AT, rear diff, driveshafts and tail shaft.

I am trying to do this as easy as possible without requiring the need to replace the cluster or the key my Outback currently uses, though not an issue I just don't want to have to go through the trouble of matching my original cluster KM's with the replacement cluster just yet. Though I know it's possible to completely remove the immobiliser requirement altogether, that will remove the need for the key fob and the ignititon barrel sensor to match with everything else.

My concern with this swap are fuel lines and location, engine bay wiring (cooling fans etc etc), Brake booster. If I have the rear diff, tail shaft and transmission from an EZ30 equip model (Liberty 2005) which should be a direct bolt in... I'm looking for help in regards to all of the above plus the 5AT and fuse box wiring. Even if my 2.5L EJ253 wiring loom magically has the same pinout as the EZ30 for the transmission... would I still need to match the pinout from the cluster? Surely it's not completely different between both cars.

For reference EZ30 from a 2005 Liberty and my car is a 2007 Outback...

Just looking for some guidance, thanks.
1 - 9 of 9 Posts

· Super Moderator
Outback 2011 3.6R Premium (sold Jan 22)
Joined
·
4,575 Posts
Probably not going to get much guidance for this swap on this forum as it is an uncommon swap.

At a guess there may be one or possibly two forum members out of 164,000 forum members that may have some knowledge of this swap.

I believe there are other forums (maybe legacygt) that will have far more experience and knowledge.

Good luck with your project, maybe you can give us some updates as you do the swap.

Seagrass
 
  • Like
Reactions: jeisensc

· Premium Member
01 VDC, 05 R Sedan, 06 BAJA EJ257
Joined
·
19,129 Posts
You need the H6 wiring harnesses, engine and interior, and all the computers; ECM, TCM, ABS/VDCCM, BIU, instrument cluster. The engine and trans are wired different. The interior is wired different. The ABS/VDCCM has to match the ECM and TCM for communications and all that runs through the BIU.

The rear diff is the same gear ratio between the two cars, you may want to verify that. 4.11:1

If you got the H6 car on the cheap, have plenty of time and patience, then put the two in the shop and tear them apart. Label everything. If the H6 is a sedan, you'll have some extra work for the tail lights and rear wiper on the Outback.
 

· Premium Member
01 VDC, 05 R Sedan, 06 BAJA EJ257
Joined
·
19,129 Posts
Also, taking the interior harness out means removing the dash panels, so may as well swap over the whole setup, including the cluster. May as well swap the steering column.
 

· Registered
Subaru Outback 2007, 2.5L, EJ25, Auto, Non Turbo
Joined
·
48 Posts
Discussion Starter · #6 ·
You need the H6 wiring harnesses, engine and interior, and all the computers; ECM, TCM, ABS/VDCCM, BIU, instrument cluster. The engine and trans are wired different. The interior is wired different. The ABS/VDCCM has to match the ECM and TCM for communications and all that runs through the BIU.

The rear diff is the same gear ratio between the two cars, you may want to verify that. 4.11:1

If you got the H6 car on the cheap, have plenty of time and patience, then put the two in the shop and tear them apart. Label everything. If the H6 is a sedan, you'll have some extra work for the tail lights and rear wiper on the Outback.
Yeah I got the H6 on the cheap, crashed front end and evidence of the car being rolled (has roof damage)... so Yeah I'm fully willing to do the swap just want to know what talks to what and if I need the entire loom. Don't think ABS needs to be swapped from the H6, should just work with whatever uinit it's plugged into, they shouldn't be paired/coded to one particular computer (from memory).

When you say loom do you mean the entire car loom? Can't I just chop it from the firewall/cluster back and join onto existing harness? Match up wires, I'm sure Subaru wouldn't have made completely different harnesses for the 2 cars... surelyyyyyyyyyyyyy.

I was just gonna swap the cluster, TCU, ECU steering column with ignition barrel and the key reader and call it a day... but when I ask about this swap nobody seems to give me the direction just how annoying it will be?
 

· Registered
Subaru Outback 2007, 2.5L, EJ25, Auto, Non Turbo
Joined
·
48 Posts
Discussion Starter · #7 ·
Also, taking the interior harness out means removing the dash panels, so may as well swap over the whole setup, including the cluster. May as well swap the steering column.
Yeah, well the interior is cream so I'm not swapping that uglyness into my car... but I get you. All that stuff will be scrapped I don't need it... may as well verses ACTUALLY NEED TO DO are completely different. If I don't need to remove this I won't. I originally was going to keep my original everything and just swap over the ECU and delete the immobilser requirements from the ECU... but it's not that easy
 

· Brucey
Brucey
Joined
·
13,302 Posts
You're going to have to remove the dash. There is simply no way around it.

The wiring is completely different between the four and the six.

You'll have to remove the crash beam, the air bags, the ECU/TCU, the glove box, the gauge cluster, the center console, likely the seats, the heater core, blower, and entire HVAC system is going to have to come out.

The wiring harness is the first thing that goes in these cars when they're built. So everything else is on top of it.

Here is an idea of how far you have to go:


I did go a little further and also swapped the VDC system in from the donor car which added more work for me. However, the interior is going to have to get to the same point shown in the video.

I have a thread as well documenting everything:

 
1 - 9 of 9 Posts
Top