Welcome to the North American Subaru Impreza Owners Club Monday November 19, 2018
Home Forums WikiNASIOC Products Store Modifications Upgrade Garage
NASIOC
Go Back   NASIOC > NASIOC Technical > Normally Aspirated Powertrain

Welcome to NASIOC - The world's largest online community for Subaru enthusiasts!
Welcome to the NASIOC.com Subaru forum.

You are currently viewing our forum as a guest, which gives you limited access to view most discussions and access our other features. By joining our community, free of charge, you will have access to post topics, communicate privately with other members (PM), respond to polls, upload content and access many other special features. Registration is free, fast and simple, so please join our community today!

If you have any problems with the registration process or your account login, please contact us.
* Registered users of the site do not see these ads. 
Reply
 
Thread Tools Display Modes
Old 01-10-2012, 12:19 PM   #1
Needablk07
Scooby Newbie
 
Member#: 188216
Join Date: Aug 2008
Chapter/Region: MAIC
Location: Balitmore,MD
Vehicle:
2006 STI
OBP

Default 2.5 RS Motor Swap HELP

So i recently purchased a 2005 R.S with some engine nosie. The pervious owner said it might be rod knock, so i am looking into swapping/rebuliding the motor. My question is i have someone selling a 2008 2.5 impreza non turbo motor. I know the motor in my RS right now is a ej25, if that 2008 has the same motor will it be a direct swap??

Also i would like to know what other motors will swap right into that car without having to change anything really big out. Thanks.
* Registered users of the site do not see these ads.
Needablk07 is offline   Reply With Quote
Sponsored Links
* Registered users of the site do not see these ads.
Old 01-10-2012, 01:42 PM   #2
TravisL
Scooby Newbie
 
Member#: 288101
Join Date: Jul 2011
Default

Don't entirely take my word for it as I was swapping into an older 02' outback but this is what I think you'll run into.

The 08' will have the same short block, I'm going on a bit of a limb in saying the 05' is also an ej253 same as the 08'. What I know should be different is the i-avls that the 08' is equipped with, you would have a headache trying to make it operate exactly as it did form the factory. You could also build a controller for it and run it in a dumbed down rpm based state only, from my reasearch it's in high lift mode alot more than it is not.

I would think just about any SOHC EJ25 would be a fairly straight forward swap, just swap intake and possibly cam/crank gears so the triggers remain the same for your ecu. EGR stuff might be a little different, but should be fairly easy to sort, was in my case.

You could also use the 05' non-i-avls heads on the 08' ej253 short block I believe. Only reason I'm not certain on that is the ej251 heads will not work on a 253, but I'd like to think 253 non-iavls heads will fit and clear valves/pistons on an iavls engine(should).
TravisL is offline   Reply With Quote
Old 01-10-2012, 04:08 PM   #3
Needablk07
Scooby Newbie
 
Member#: 188216
Join Date: Aug 2008
Chapter/Region: MAIC
Location: Balitmore,MD
Vehicle:
2006 STI
OBP

Default

Thanks for all the help. I am pretty sure the two cars have the same motor in them. The motor out of the 08 i am going to try and get the ECU and engine harness so if i have both ECU and harness it should just be a direct swap correct??
Needablk07 is offline   Reply With Quote
Old 01-10-2012, 04:24 PM   #4
GEE-OTTO
Scooby Specialist
 
Member#: 201277
Join Date: Jan 2009
Chapter/Region: MAIC
Location: Arlington VA
Vehicle:
2008 08 QSM 5MT LGT
QSM

Default

A hot dip, line bore, cyl hone and possible decking with reassembly (new bearings, rings, seals, gaskets) would cost around the same as buying a newer engine and paying swap all the bits over (MAF, manifolds, heads) and then having to place trust that newer Short Block wont crap out on you 15K miles down the road.

If it is running with knock there is a good chance you can reuse most of the internals
GEE-OTTO is offline   Reply With Quote
Old 01-10-2012, 04:39 PM   #5
Needablk07
Scooby Newbie
 
Member#: 188216
Join Date: Aug 2008
Chapter/Region: MAIC
Location: Balitmore,MD
Vehicle:
2006 STI
OBP

Default

Ok thanks for the help. So basically pull the motor and see what we are working with?? But If i get a new motor swap with 29K or so on it with the ECU and harness would it just drop right in??
Needablk07 is offline   Reply With Quote
Old 01-15-2012, 04:25 PM   #6
Needablk07
Scooby Newbie
 
Member#: 188216
Join Date: Aug 2008
Chapter/Region: MAIC
Location: Balitmore,MD
Vehicle:
2006 STI
OBP

Default

Need some more help. Got someone selling a ej255 shortblock. Will the heads from my 05 r.s bolt up?? Need to know my options. Thanks for the help.
Needablk07 is offline   Reply With Quote
Old 01-17-2012, 01:20 AM   #7
Needablk07
Scooby Newbie
 
Member#: 188216
Join Date: Aug 2008
Chapter/Region: MAIC
Location: Balitmore,MD
Vehicle:
2006 STI
OBP

Default

Need some advice thanks.
Needablk07 is offline   Reply With Quote
Old 01-20-2012, 11:11 PM   #8
ballitch
Scooby Specialist
 
Member#: 74907
Join Date: Nov 2004
Chapter/Region: NWIC
Location: salem, OR
Vehicle:
98 cam'd EJ251
Wrx Tranny,slowr than ish

Default

What is your current engine code? EJ251 or EJ253, you can find it on the driver side strut tower on a plate that is riveted to your strut tower.

Do you have AVLS heads?


~Josh~
ballitch is offline   Reply With Quote
Old 01-21-2012, 09:29 AM   #9
Patrick Olsen
NASIOC Supporter
 
Member#: 120
Join Date: Jul 1999
Chapter/Region: AKIC
Location: Where the Navy sends me...
Vehicle:
1997 Legacy 2.5GT
1996 Impreza coupe

Default

Quote:
Originally Posted by Needablk07 View Post
So i recently purchased a 2005 R.S with some engine nosie. The pervious owner said it might be rod knock, so i am looking into swapping/rebuliding the motor. My question is i have someone selling a 2008 2.5 impreza non turbo motor. I know the motor in my RS right now is a ej25, if that 2008 has the same motor will it be a direct swap??

Also i would like to know what other motors will swap right into that car without having to change anything really big out. Thanks.
AFAIK any '99-'05 Impreza or Forester 2.5L, and any '00-05 Legacy 2.5L will be the same. The '08 engine is different in that it has the newer i-AVLS heads (variable lift), so it would not be a direct swap into your car. You might be able to use the shortblock from the '08 with your '05 heads/intake/sensors. See TravisL's comments about EJ251 vs EJ253.

Quote:
Originally Posted by TravisL View Post
Don't entirely take my word for it as I was swapping into an older 02' outback but this is what I think you'll run into.

The 08' will have the same short block, I'm going on a bit of a limb in saying the 05' is also an ej253 same as the 08'. What I know should be different is the i-avls that the 08' is equipped with, you would have a headache trying to make it operate exactly as it did form the factory. You could also build a controller for it and run it in a dumbed down rpm based state only, from my reasearch it's in high lift mode alot more than it is not.

I would think just about any SOHC EJ25 would be a fairly straight forward swap, just swap intake and possibly cam/crank gears so the triggers remain the same for your ecu. EGR stuff might be a little different, but should be fairly easy to sort, was in my case.

You could also use the 05' non-i-avls heads on the 08' ej253 short block I believe. Only reason I'm not certain on that is the ej251 heads will not work on a 253, but I'd like to think 253 non-iavls heads will fit and clear valves/pistons on an iavls engine(should).
I'm no expert on the various iterations of the SOHC motors, but I think all of this is correct.

Quote:
Originally Posted by Needablk07 View Post
Thanks for all the help. I am pretty sure the two cars have the same motor in them. The motor out of the 08 i am going to try and get the ECU and engine harness so if i have both ECU and harness it should just be a direct swap correct??
That assumes the ECU and harness tie into the body harness in the same way, which is unlikely since you're talking about two different generations of Impreza.

Quote:
Originally Posted by Needablk07 View Post
Need some more help. Got someone selling a ej255 shortblock. Will the heads from my 05 r.s bolt up?? Need to know my options. Thanks for the help.
Yes, they'll bolt up, but you'll end up with a low compression ratio due to the dish in the turbo motor's pistons, so the engine would be a bit of a dog.

Quote:
Originally Posted by ballitch View Post
Do you have AVLS heads?
He shouldn't. 2006 is the first year with the i-AVLS on the 2.5i.
Patrick Olsen is offline   Reply With Quote
Old 01-21-2012, 06:06 PM   #10
Needablk07
Scooby Newbie
 
Member#: 188216
Join Date: Aug 2008
Chapter/Region: MAIC
Location: Balitmore,MD
Vehicle:
2006 STI
OBP

Default

Thanks for all the responses. I am fairly sure that the engine code is EJ253 for the motor that is in the car right now. The motor i want to buy has a label on the front of the timing cover with the first 5 characters EJ253 which also matches the label on the current motor that is in the car now. So my questions if the codes are the same would it be a simple swap if i had the motor, harness and ECU for the new engine?? Thanks.
Needablk07 is offline   Reply With Quote
Old 01-22-2012, 07:34 PM   #11
Needablk07
Scooby Newbie
 
Member#: 188216
Join Date: Aug 2008
Chapter/Region: MAIC
Location: Balitmore,MD
Vehicle:
2006 STI
OBP

Default

Anyone??
Needablk07 is offline   Reply With Quote
Old 01-22-2012, 08:37 PM   #12
mod maniac
Scooby Specialist
 
Member#: 300551
Join Date: Nov 2011
Chapter/Region: SCIC
Location: mariposa ca.
Vehicle:
2002 FOZ STI 2.34
Fullers Garage

Default

If the engine codes are the same they should swap however you should swap your intake over to the new engine because the wiring may be different. You cant just swap the ecu because the wiring may be different between engine and ecu.the easist way is to swap intake. that shortblock should work also with your heads and intake.
mod maniac is offline   Reply With Quote
Old 01-23-2012, 12:12 AM   #13
Needablk07
Scooby Newbie
 
Member#: 188216
Join Date: Aug 2008
Chapter/Region: MAIC
Location: Balitmore,MD
Vehicle:
2006 STI
OBP

Default

Intake meaning the throttle body, intake piping and filter?? If I have the ecu and harness for the new engine and the codes are the same and it is a usdm motor and car I should be set than right??
Needablk07 is offline   Reply With Quote
Old 01-23-2012, 12:26 AM   #14
mod maniac
Scooby Specialist
 
Member#: 300551
Join Date: Nov 2011
Chapter/Region: SCIC
Location: mariposa ca.
Vehicle:
2002 FOZ STI 2.34
Fullers Garage

Default

Intake means that metal thang that bolts to the top of both heads. If you use that and the wiring harness from your old motor it should work. the ecu will be different from 05 to08 the wiring may be different also so to avoid problems use your old ecu, intake and engine wiring harness.
mod maniac is offline   Reply With Quote
Old 01-24-2012, 04:00 PM   #15
Needablk07
Scooby Newbie
 
Member#: 188216
Join Date: Aug 2008
Chapter/Region: MAIC
Location: Balitmore,MD
Vehicle:
2006 STI
OBP

Default

So the full intake manifold??
Needablk07 is offline   Reply With Quote
Old 01-24-2012, 04:46 PM   #16
geronimo81
Scooby Specialist
 
Member#: 154586
Join Date: Jul 2007
Chapter/Region: BAIC
Location: San Ramon
Vehicle:
1996 Turbo Outback
9psi on 91 No EM

Default

No, just because both say ej253 does not mean that they are the same. The shortblock will be the same but the heads/sensors/accessories might be different depending on the year/model of the donor car.

Have you had a mechanic confirm that you even have rod knock? I wouldn't take the POs word for it.
geronimo81 is offline   Reply With Quote
Old 01-24-2012, 05:04 PM   #17
Needablk07
Scooby Newbie
 
Member#: 188216
Join Date: Aug 2008
Chapter/Region: MAIC
Location: Balitmore,MD
Vehicle:
2006 STI
OBP

Default

Got yea. Thanks for the help. It's out of an 08 Impreza. So I am guessing the newer model will have different sensors than the 05 Impreza rs?? Haven't had anyone confirm it but I am in automotive school, spoke with my instructor and he said from what I am hearing that it is a main bearing problem. I was thinking about dropping the oil Pan to take a better look but honestly if I can get another lower mileage motor for a low price and drop it in I feel it's a little less headache. Than take the bad motor out and take my time and see what the real problem is.
Needablk07 is offline   Reply With Quote
Old 02-23-2012, 11:16 AM   #18
Needablk07
Scooby Newbie
 
Member#: 188216
Join Date: Aug 2008
Chapter/Region: MAIC
Location: Balitmore,MD
Vehicle:
2006 STI
OBP

Default

Need a little more help. Got the new motor and everything ready to go in and it was the new 08 motor has valve timing on the cams. The motor that came out doesn't. I have been reading swapping the heads is a quick was to fix that but i just want to drop the motor in. I have the full engine to cabin harnness and the ecu. Just swapping those harnesses out will work??
Needablk07 is offline   Reply With Quote
Old 02-23-2012, 01:09 PM   #19
5k077
Scooby Newbie
 
Member#: 128235
Join Date: Oct 2006
Location: Tampa, FL
Vehicle:
2007 WRX

Default

Just swap the heads. Less headache.
5k077 is offline   Reply With Quote
Old 02-23-2012, 01:20 PM   #20
Needablk07
Scooby Newbie
 
Member#: 188216
Join Date: Aug 2008
Chapter/Region: MAIC
Location: Balitmore,MD
Vehicle:
2006 STI
OBP

Default

That's what I am finding out. Now if I have a spun bearing you think the heads might alright to reuse??
Needablk07 is offline   Reply With Quote
Old 02-23-2012, 01:23 PM   #21
GrundleJuice
Scooby Specialist
 
Member#: 165749
Join Date: Dec 2007
Chapter/Region: South East
Location: Central Floriderp
Default

Quote:
Originally Posted by Needablk07
Need a little more help. Got the new motor and everything ready to go in and it was the new 08 motor has valve timing on the cams. The motor that came out doesn't. I have been reading swapping the heads is a quick was to fix that but i just want to drop the motor in. I have the full engine to cabin harnness and the ecu. Just swapping those harnesses out will work??
With an 07 engine/ecu it would. The 08 uses a whole new ecu type and protocol so it might not be comparable with thw chassis side. Not 100% sure, though.


Quote:
Originally Posted by 5k077
Just swap the heads. Less headache.
That would require machining the heads and deck to true. Not just a slap em in and go, thing.

Lesser of two evils I guess.
GrundleJuice is offline   Reply With Quote
Old 02-23-2012, 01:40 PM   #22
Needablk07
Scooby Newbie
 
Member#: 188216
Join Date: Aug 2008
Chapter/Region: MAIC
Location: Balitmore,MD
Vehicle:
2006 STI
OBP

Default

If I can get the complete firewall harness for the 08 2.5I will it swap right into the 05 .
Needablk07 is offline   Reply With Quote
Old 02-23-2012, 07:44 PM   #23
DiagTech
Scooby Newbie
 
Member#: 176286
Join Date: Apr 2008
Chapter/Region: W. Canada
Location: Prince Rupert, BC, Canada
Vehicle:
2000 Impreza OBS-T
Matte Black/Beige

Default

Swap the block, clean the heads up and be done with it. Labour time will be a fraction of swapping engine/electronics.
DiagTech is offline   Reply With Quote
Old 02-23-2012, 08:22 PM   #24
Needablk07
Scooby Newbie
 
Member#: 188216
Join Date: Aug 2008
Chapter/Region: MAIC
Location: Balitmore,MD
Vehicle:
2006 STI
OBP

Default

Yeah sounds like what I am going to do. Thanks for the help. What should the cleaning consist of?? Should I take the heads to a machine shop and have them make the call?? Also what else should I be replacing on these ej253 engine?? Thanks for all the help.
Needablk07 is offline   Reply With Quote
Old 02-23-2012, 09:00 PM   #25
DiagTech
Scooby Newbie
 
Member#: 176286
Join Date: Apr 2008
Chapter/Region: W. Canada
Location: Prince Rupert, BC, Canada
Vehicle:
2000 Impreza OBS-T
Matte Black/Beige

Default

You want to search head gasket replacement. Many people have many different methods. I would replace required gaskets, clean block/head mating surfaces, wash the heads well if there is metal in the oil.
DiagTech is offline   Reply With Quote
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
WTT 02 wrx motor or ej20h For stock 2.5 rs motor sti=heaven Private 'Wanted' Classifieds 0 07-29-2009 01:51 AM
2.5 RS T or 2.5 RS Sti swap V3rdug0 Newbies & FAQs 3 03-09-2006 03:44 PM
fs:99 2.5 rs motor drift king Private 'For Sale' Classifieds 10 03-04-2005 04:33 AM
1998 2.5 rs motor dohc on ebay turbocolin Tri-State Area Forum 0 09-28-2004 03:35 PM
WTB: WRX or 2.5 RS motor CatchMyDrift Private 'Wanted' Classifieds 13 06-13-2004 01:04 PM

All times are GMT -4. The time now is 03:33 AM.


Powered by vBulletin® Version 3.7.0
Copyright ©2000 - 2018, Jelsoft Enterprises Ltd.
Powered by Searchlight © 2018 Axivo Inc.
Copyright ©1999 - 2017, North American Subaru Impreza Owners Club, Inc.