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Hey guys, my girlfriend's MY00 2.5L Outback blew its engine to disrepair last week - and not having a spare car for work - we're pretty desperate to get it back on the road. My brother has a Forester MY00 2.0L [both vehicles are AUTOs] that he'll donate the engine from, so was wondering if this is a compatible swap? I've read that we'd have to swap the intake manifold over to suit wiring/ecu, but other than this, would you expect any issues and other things that would have to be done during the install -- or is this a nightmare in the making? Thanks for any suggestions/help in anticipation, cheers Peter.

It could be done but a lot of effort and I think you'd hate the power reduction.

If you're not to far from Anglesea, I'd look into this.. it's 'negotiable'
http://www.gumtree.com.au/s-ad/anglesea ... 008256075#



Oh.. Hi and Welcome to AUSubaru

Hey, thanks for the reply, welcomming, and advert 'heads-up'...i'm still leaning towards the swap, however, as the 2.0L is free I'm not adverse at swapping engines, but if it's going to lead to many modifactions and fabrication, I agree, it's not worth it; powerloss doesnt concern me either. Do you have any idea what would be involved further to what I assumed about the manifold? Thanks ever so much for your help thus far Cheers Peter

Ok.. the price of the EJ20 makes it hard to compare.

If I was swapping it over, I'd use the bare long EJ20 engine, then swap all the manifolds over and all sensors. I'd also check that the crank angle timing gear has the same timing tabs on it, if not swap them over too.

The EJ20 will run a little richer (fuel wise) than the EJ25 but the ECU will learn to a small degree but not that much.

To do it properly, you'd need to swap the complete wiring loom and ECU over but too much work (IMO). What has happened to the old EJ25? can you not buy the bits that are broken and refix?

Id be weary of running a 2.0 off a 2.5 ECU as these engines use a MAP sensor not a MAF sensor, so the ECU has no way of noticing the reduced air flow. 20% is a fair difference in displacement.

I wouldnt be surprised if you could actually directly swap the ECU. Get a pinout of both and compare them.

Gannon wrote:Id be weary of running a 2.0 off a 2.5 ECU as these engines use a MAP sensor not a MAF sensor, so the ECU has no way of noticing the reduced air flow. 20% is a fair difference in displacement.

I wouldnt be surprised if you could actually directly swap the ECU. Get a pinout of both and compare them.

Very true Gannon and I too would be very weary if it was going from EJ20 to EJ25 but being the other way, the only thing will be extra fuel and at 20% that is no issue in making it not run. Like I mentioned, it will make the EJ20 run richer but in theory it will be the same or less than the EJ25.

I too would like to see the difference in ECUs, that would be awesome if they could do a straight swap.

RSR 555 wrote:Ok.. the price of the EJ20 makes it hard to compare.

If I was swapping it over, I'd use the bare long EJ20 engine, then swap all the manifolds over and all sensors. I'd also check that the crank angle timing gear has the same timing tabs on it, if not swap them over too.

The EJ20 will run a little richer (fuel wise) than the EJ25 but the ECU will learn to a small degree but not that much.

I'm doing the exact opposite with my Forester. Putting in a 2.5l (Outback or Impreza) block into my 2001 2.0l Forester. For a 25% power increase over what I have But since mine would run lean rather than rich I am getting an ECU piggyback to compensate and supply more fuel to the motor (using my 2.0l manifold, wiring and ECU).

You'll hate the power loss especially behind the auto but if it's free that is hard to beat. Best of luck, let us know how it goes