subaru FB25 engine interchange

In reply to jdf60 :

All the swap success stories say to swap the wiring harness and sensors if needed, it keeps the computer happier. Does the new EGR mount to the manifold instead of the crossover water pipe assembly and have a separate silver cooler? The old EGR cooler was inside the crossover water pipe.

Yes 13-14 Legacy and 14-16 Forester are most similar. Also more expensive.

What general part of the country are you in? I'm in Oklahoma, local pickings are pretty slim.

In reply to mildensteve :

agreed about the other simple swaps. I hadn't done enough research to realize the harness and egr and intake wouldn't match up, guess I was gambling a little that the '14 was a little closer. Was just kind of frustrating to see all the changes when I got the engine. 

I did notice that the intake butterfly valves looked like they operate in reverse of the forester.

What I can do in the meantime is do the harness and all the other simple changes and go ahead and drop it in. Then just see what happens with the forester intake on the legacy. It probably won't run right but hopefully in the meantime I/we figure out how to correct the tgv issue on the 1 piece intake. 

Skenton said:

Yes 13-14 Legacy and 14-16 Forester are most similar. Also more expensive.

 According to my parts list and eBay picture research the Forester engines are the same from 2014-2016 and very similar to the 2011-2013 Foresters, the primary difference being the front timing cover mount due to the power steering change to electric in 2014.  The 14-16 Foresters have the same 2-piece intake system and share the same EGR tube with the 2011-2013 Foresters, they are that similar.  The 13-14 Legacy shares the same EGR tube / intake system as the 11-16 Forester.  The 2015+ Legacy has the different EGR system. The problem has been the later Forester engines cost about twice as much as the Legacy engines. 

Skenton said:

In reply to jdf60 :

All the swap success stories say to swap the wiring harness and sensors if needed, it keeps the computer happier. Does the new EGR mount to the manifold instead of the crossover water pipe assembly and have a separate silver cooler? The old EGR cooler was inside the crossover water pipe.

Yes 13-14 Legacy and 14-16 Forester are most similar. Also more expensive.

What general part of the country are you in? I'm in Oklahoma, local pickings are pretty slim.

Well  now,  I missed this post somehow. I am also located in OK!  NE OK to be more specific!    Small world. 
 

yes I think it has the external egr cooler. Which I don't thing is a problem as long as we use the '15 intake right?  I was just looking at how I might use the 13 intake on the '15 mainly as a test until tgv issues can be sorted.   But I also like your  idea of swapping wires left to right if that works. I don't mind a code now and then as long as it runs good. 

im also curious how others on here claiming to have done the swap using '15+ legacy  got away without tgv problems. 
 

jdf60 said:

im also curious how others on here claiming to have done the swap using '15+ legacy  got away without tgv problems. 

Except for the one guy who did all the TGV modifications in the previous post I don't think they "got away" with anything.  One replied to me that they ignore the codes.  Another said they tie-wrapped the old TGV off to the side, plugged it into the old harness and faked the system into thinking it was working.  Ignoring and faking probably won't float when the inspections come due here in North Texas (Howdy neighbors!).

In reply to mildensteve :

what kind of inspections do you have to pass?  Are the tgv emission related?  I thought they were just "chokes". I do want them to work because it gets chilly up here in the winter. But we don't have inspections in OK. 
 

Im still not convinced the old intake won't work on the '15 legacy engine, other than the egr routing. The intake ports don't perfectly match, but they do seem to seal off fine.  I'll keep posting what I come up eith. 

Oklahoma no longer does any car inspections so it is a non issue here, but the engineer in me wants to do it "right". I have been unable to find a cheap one piece manifold to experiment with. Pull-a-part in OKC would be $20ish, but they do not have any suitable vehicles. LKQ would be $75ish but ditto for Tulsa and OKC inventory. Online cost via car-part.com, ebay.com etc is no better.

The TGV tumble generator valves are separate from the throttle and only used during cold start to improve mixing for emission reasons. If codes are not an issue, making sure they are open and unplugging the actuators might work OK unless it triggers some sort of limp mode. TGV delete is a common performance mod on Subaru turbo engines for the rally crowd.

The TGVs operate mirror image left/right and either both rotate toward the center or outside of the manifold depending on the year. Swapping the harness should work, but requires extending the wires to reach. Swapping pins 4&5 in the TGV connectors reverses the 12Vdc +/- wires to the motors which are reversable in normal operation anyway. What the Forester computer does with the 5Vdc open/closed signal being squirrely after either wiring change is unknown.

North Texas, DFW area specifically, has emissions inspections.  The techs plug in and check the codes.  Not sure if the TGV code itself is looked at but any CEL will fail inspection.  Maybe if jdf60 would like to "loan" his single piece intake to skenton there may be some experimentation to get this resolved simply.

And I sympathize with skenton about the "engineer-in-me" statement.  Been one for almost 40 years...

In reply to Skenton :

I'm also an engineer! . I've been in off road drivetrain design for 25 years for a large construction/ag equipment manufacturer. 
 

I would be glad to loan my intake in pursuit of this joint effort!  The only thing is that I may need part of it to get this darn forester running for my son. If I end up needing the risers/tgv as dummies like you suggest.  If it were just a project car that we didn't need in a hurry I'd just send it to you now. And if we figure out how to make it work in the meantime you likely wouldn't need it for experimentation. But either way I'm open to helping out. Even willing to donate some cash to help buy one if that would help you figure it out. My engineering skills are more related to structures and tranny/ gear/housing design than controls. But I do wish I had more time to help in testing and figuring things out.   

my real car is a 67 impala SS big block.  No codes to fool with there!

But I do get annoyed with codes as well.  I currently drive a 20 year old dodge Cummins  and wife has a 300k mile Honda Pilot both running great. Only code is a vtm code on the Pilot I can't figure out yet. But we really just need this darn Subaru driving soon for my son so he can get to work. So he may have to live with some stray codes for a while. 

In reply to Skenton :

My other concern after pulling the wiring harness off the '15 legacy is the egr setup. The wiring is different and as you know all the coolant and exhaust routing are different. I'm wondering if the new egr setup on the legacy will just plug into the wiring on the forester and play nice?  The plug and main egr valve look the same if I remember right.  Other option would be an egr delete but I don't know anything about doing that yet and what other problems would arise. 

I would hazard a guess that the CVT transmission cooler water/coolant hoses can be repurposed for the new EGR cooler if needed.

If you can temporarily pull off the TGV actuators and take a pair of closeup pictures of the 2015 TGV gear and magnet mechanism with a note indicating open and closed it would help. If it looks safe to do so,  removing the nut on the end of the shafts and laying out the gear & magnet etc pieces for another pair of closeup pictures before putting it all back together (probably  with some new thread locker) that would be even more helpful. I want to visualize the indexing tab/slots for the shaft, butterfly gear and magnet mounts. The actual butterfly mechanism inside the manifold is probably difficult or impossible to disassemble without damage and not really germane to the issue.

Are the one piece plastic manifold "upper and lower" really one piece or separate parts glued, melted or snapped together after the butterfly mechanism was inserted?

I assume the actuator motors are self locking so if you put things back together "open" and leave the TGVs unplugged when you drop the engine into the car hopefully it will get your son on the road ASAP, codes not withstanding :-)

According to the on line inventory of all the "pull your own parts" places within sane distances of me there are no suitable intake manifold donors available. Are things any better "out there"?

I gave the '66 mustang 289-V8 to one of my daughters when she graduated. It was getting to low to the ground for my hips . . . The only silicon in that car is in the glass :-)

jdf60 said:

my real car is a 67 impala SS big block

Funny how engineers who work on cars have "real cars".  Mine are a 70 RT/SE Challenger 440 and a 65 A-Code Fastback Mustang among others. 

Back to the Subaru - engine is out and field stripped of all wiring, sensors, flex plate, timing cover, intake, etc. down to the long block.  Just need new engine.

Removed, prior to disassembly

Stripped.  Still have some goodies left on, depending on the donor block.

In reply to mildensteve :

cool cars!  Mine is a convertible. I'd rather be driving it in this nice fall weather than working on my sons daily driver!  

Looks familiar.  I've got both of mine stripped down now (13 & 15 legacy). Switching out the tone wheels on the cams and the timing cover and  next will do the wiring harness and sensors. I'm surprised at how loose all the bolts seem on the Subaru. Compared to the Honda anyway. 

also surprised a bit at how loose the rockers are. I tried to measure clearance and they both seem around 15 thou. Hard to measure though woth my crude shims. 
 

are you going to put a new timing chain/tensioners on while you have it apart?  Mine both seem in perfect shape but they are just right there!  I'm not sure if they ever even need replacing on these engines. I guess I should look that up. 

In reply to Skenton :

I'll try to get some pics. I know I keep saying that but I get busy out there and forget. And I'm not getting much free time lately in the shop. 
 

I tried to move the actuators bu hand but they don't move easily. I'll get them off and see what's going on. 

I would not expect them to move easily since they are normally unpowered and expected to stay put which is why I assume the motors are self locking. 12Vdc to actuator pins 4&5 or reverse (see upthread for diagram) should zip them right along. Just do not run them for more than 10 seconds according to Subaru to avoid over heating.

In reply to Skenton :

Well I got a few pics of the 15 tgv. I couldn't get the darn Phillips screws off the 13. I'll have to grind those off probably. But maybe this will help. They definite open opposite of each other. 
 

I'll try to post the pics here. But they look distorted for some reason. I even tried to resize them smaller. 
 

I ran out of time and didn't get to taking the shaft nut  off. I'll try that tomorrow. 
 

any ideas on fuel injectors?  The plugs are the same at least. 
 

there's not too many other sensors to change that I can see. Most come with the timing cover. I think the only others are the flywheel/crank position sensor and the coolant temp sensor.  

jdf60 said:

any ideas on fuel injectors?

 Fuel injector part numbers are different between the Legacy and Forester, probably because of the intake system differences.  Since you are using the old harness better check the connector to make sure it fits.  But that hasn't been one of the items ever reported as being an issue.

How many miles on your donor engine?  The intake looks a little oily, but NOTHING like mine that was an oil burner.  After 130k miles of blow-by the oil residue was so thick on the intake passages that I could literally scoop out a thick paste with a spoon from the walls.  According to the records I found in the car it it ruined a brand new catalytic converter in about 10k miles.

In reply to mildensteve :

The legacy engine had about 90k and the forester has 199k. The legacy seems tighter all around and cleaner inside. But the intake is a little black yet not gummy like yours. I'll probably clean it. I'd like to just get new injectors but they aren't cheap.  And I'm not sure which ones I'd get. But like you said others have used the newer style ok as far as we know. And I think the plugs are the same. As long as everything else is the same and they play nice I'd rather use the legacy injectors. The combustion chmaber looks fairly clean also. I don't think this legacy was a big oil burner. 

forester

legacy

So dar im planning to replace the folowing

radiator

coolant hoses

belt

thermostat

wwter pump

idler pulleys

belt tensioner

spark plugs

about $260 so far on rock auto for all this  almost what I paid for the engine! 

i hate to spend much more in case I end up with a brick!  

In reply to jdf60 :

Wow.  Those look clean inside, not brown like my oil burner.

The pictures of the 2015 TGV gears and actuator helps make more sense of the modifications done by the one person who made it work (ref previous link above).  Since I have my old TGV's removed I may re-read his process with those in hand.  Would help if I had a new one beside it.  You might want to read it as well to see if it makes sense.  At least I now understand what he meant by the sensor magnets being opposite of the older set up.

jdf60 said:

So far im planning to replace the following

Don't forget to change the cam trigger wheels.  I see one has the external tabs vs the internal slots of the other. 

And at 199k miles on the original, I'd say you got your money's worth.

And and you won't end up with a brick.  The TGV will have a fix.