DOHC to SOHC Swap

[Masher100]

I have a really nice 98 Forester 2.5 DOHC standard trans i was wonder what difficulties i would have swapping in a 03 SOHC 2.5 from a Outback auto trans The car was hit runs great just not drive able.

if there is a previous thread please direct me i didnt see it on the first several pages

Thank 

Masher

[MilesFox]

This would work only if the ej25d manifild has the same bolt pattern as the ej251, which oyu will need the ej25d manifold to match the harness. Otherwie, any 2.2 from 95-99 will be a plug in affair, given if it has egr or not. 

 

I do not know if the ej25d and the ej251 share the same intake pattern. I do know that the ej25d is a different pattern than the phase 1 ej22(9--99)The components on either intake are different, but maybe it is possible to merge the intake harness from one to the other. But i have no experience with this, i am only speculating.

Edited December 7, 2013 by MilesFox

[johnceggleston]

you can use the block from the 03,

but not the heads or the intake

if you are installing it in an 98 ej25D car.

[idosubaru]

Or rebuild the 2003? It's not hard to rebuild a wrecked car. Post pic's, we can help.

 

Or simply install an EJ22 - easy swap, more reliable engine, cheap, and easy to find...hard to beat.

 

It's not typically done and not easy/good results. To do the swap you're talking about you have to remove the intake wiring harness from the 98 forester and install it onto the 03 intake manifold. You'll still have idle issues as the idle mechanisms are different between the two and there's no simple work around. Folks prop the throttle plate open or just kind of ignore the poor idle/driving at warm up, or something like that. One member in the northeast tried welding up a fix for this and still couldn't get it to work and got rid of the engine.

 

The intake manifolds don't interchange like MilesFox just guessed.

[Masher100]

If the Block will work that may be enough, The 98 forester is in great condition, minus the bad engine, (main bearing) the 03 outback is hit hard, Driver side fender, strut, axle, lower control arm, engine mount/cross member, sway bar all shot... , the sub frame is tweaked as well right where the lower control arm bolts in.. and its a matter of economics, while obtaining all these parts is not difficult its can get costly, besides, i might have the 03 heads rebuilt as i am nursing a 04 outback with leaky gaskets... 

I guess time and funds will dictate what i do, thanks for the input