subaru FB25 engine interchange

driverfan said:

Greetings,

Thanks for the great guidance on this thread.  I just swapped a 2015 Legacy FB25 into my mother in law's 2012 Forester.   I guess I got lucky, because it started on the first try.  I've only driven it about 5 miles, but no codes yet.  Here are a few things that worked for me:

1. Move all sensors from the old engine to the new one along with the wire harness.

2. Move the timing chain cover from the old engine to the new one.  I had to do this to keep the original accessories and belt.

3. Loosen the upper transmission mount (attaches to the firewall) during reassembly.  This made it so much easier to get the engine and transmission aligned.

4. Support the exhaust manifold with a jack and use a pry bar to pop the flange over the studs.  The manifold seemed to have curled up a bit while it was off the original engine.  The flange holes were misaligned with the studs by ~1/8".

Did you have to do anything with the TGV on the intake like others have mentioned with the 2016 Legacy swap?  I found that the 2015 Legacy is very availalbe and cheaper than other options for the swap into our 2013 Forester.

I've heard a lot of issues with using a 2016 Legacy due to the intake differences and some cam/crank sensors or pickup plates that cause it to throw codes.

I am in the process of picking a donor engine for a 2011 Forester with 3 pistons and shiny metal glitter in the oil pan

Keep in mind that 2.5L Forester and Legacy FB25B engines didn't change in sync. Around here Forester engines through 2016 all cost more than Legacy engines so I am looking for a 2015 Legacy donor. As far as I can tell it should still have separate upper plastic intake manifold and aluminum lower TGV tumble generator valves, but I will want to confirm that.

I think I will need to swap the timing cover for the power steering pulley, rocker covers for the benefit of the old coils, wiring harness and some sensors for the benefit of rhe ECU, crank and cam tone wheels/reluctors/plates whatever they are called while I have the timing cover off also for the benefit of the old ECU. The throttle body has a different part and can be swapped too, but supposedly the new one is compatible. I am in the midst of sorting out the CVT inspired cooling system changes and how  best to proceed. Looking at pictures on Ebay of upper/crossover water pipe assemblies there is considerable variation out there.

Edit

On engines for MT and 4AT transmissions the upper oilpan has a water port next to the thermostat for the heater pipe. On the opposite side of the casting there are provisions for a second water port which is not used or even broached. On engines for CVT transmissions the port is drilled and has a curved pipe installed for transmissoon cooling. Looking at pictures of 2017 Forester upper oil pans on Ebay I saw examples of both configurations.

/Edit

It is a project so I am not in any great hurry though.

Until I understand the TGV issue better I also want to avoid the new all plastic intake manifold, which I believe appears on 2017 Forester and 2016-1/2 Legacy. Also,somewhere around 2020 the FB25D with direct injection superseded the FB25B.

Edit

The two TGV actuators on the manifold have the same part number but seem to operate mirror image. Looking at my 2011 wiring diagrams, they contain a 12V DC motor which can be driven either direction under ECM control by dynamically switching the plus and minus power connections. The actuators also contain sensors that output a voltage [0-12]*correction unlike the motor the sensor is* 0-5V DC proportional to the open/close angle. They are not just ON/OFF. The idea of crossing the wiring harness left to right as discussed in one of the links I posted earlier seems to have merit. I know the Denso part numbers are different for the TGV actuators on the new one piece plastic intake manifold vs the older split design. Does anyone know if they will physically swap? I looked at the Denso site for information but it said the part numbers were invalid. I guess they are an OEM only private product.

/Edit

Has anyone swapped a 2017 FB25 into the Forester?  Mine is a 2012 and making knocking noises.  I see that the 2016 has been done successfully but the 2017 engines are cheaper, lower miles, and more available.

https://www.subaruforester.org/threads/2014-how-to-install-a-2017-engine-into-a-2011-2016-vehicle.836125/

I found this and posted it about a page up thread recently. I am still researching it.

There seems to be some question exactly when the one piece plastic intake manifold with rectangular ports and TGV changes entered production on different vehicles. The TGV changes seem to be the show stopper for most folks.

The idea in that post about crossing the wiring harness left/right for the TGV actuators is sound from an electrical point of view. I am still studying the magnet change. The sensor is in the TGV actuator and the magnet is in the manifold TGV mechanism. I have recently seen pictures of one piece manifolds using the same Denso 012010-6110 actuators used in previous years as well as Denso 012010-6111 later on. Not sure if it relates to intake manifold part number 14001AC33 vs 14001AC33A but I am assuming the two actuators are physically interchangable. That post says the magnets are incompatible and must be swapped, which I can believe but do not understand, yet.

Edit

My 2011 service manual says the TGV sensor in the actuator outputs a signal between 0-5V DC

Can anyone with access to service info for newer models with the one piece plastic intake manifold check to see if that has changed and report back?

/Edit

In reply to mildensteve :

I actually just ordered a 2015 Legacy 2.5L for about $370, plus $210 freight from LKQ, this one had around 100k miles, which for a car that's worth about $4000 and has 200k miles I think that is a good fit.  This is for the 2013 Forester.  They seem to have better prices on ebay plus you get a little extra protection, maybe.  I found that the 2016-2017 were a little more expensive.  I didn't even look at Forester engines because they are much more expensive and higher miles for some reason.  Maybe because most folks and/or repair shops don't realize they can use the Legacy engine.  Or they just want something strictly plug and play without fooling with the timing cover and swapping a few sensors.  

Good to hear, please keep us informed. Several reports of success with 2015 Legacy engines which is why I am considering it. But, I keep seeing pictures of 1 piece plastic intake manifolds labeled "2015,2016..." which makes me wonder if there was a mid year change or something.

Looking into the TGV issue here are some closeups of the gear and magnet mechanism. Assuming the old and new actuator are in fact interchangable the gears must be compatible and the sensors are the same so the shorter black magnet of the aluminum lower and the longer white magnet of the 1 piece plastic manifold must be the difference. I can certainly see how that would generate a different length, shape and possibly amplitude signal that would not make the computer happy. I wonder if those shafts are the same so the whole guts of that end part would swap?

In reply to Skenton :

Still waiting on my 15 legacy engine. I'm doing a few things to get the pieces off my 13 forester. Like the timing cover and maybe the valve covers to solve the plug boot length issue. 
 

does anyone know if I need to swap out anything else like sensors, etc. I've seen some folks swapping out some sensors or the cam plates and maybe the engine wiring harness. I've read so much I'm starting to forget the details. 
 

also wondering if I should replace the oil pump. I think it's bolted into the timing cover on the crank. I'm already planning to replace all coolant hoses and belts and plugs thermostat and the radiator because I broke the overflow nipple off of it. 

I would suggest replacing the water pump rather than the oil pump. Nearly every time I have dealt with an engine that had been out of service for a year or more the waterpump shaft seal quickly failed. LKQ requires it for warranty I believe.

I am going to paste my write up to myself below for your perusal. Kind of long but hopefully helpful.

≈====================

I have been reading all the threads about engine swaps for 2011-2013 Foresters with bad 2.5L engines and this is a summary of my findings about the simplest and least painful way to go about it. Mainly you have to swap parts from the old/dead engine to the used/donor engine because the parts may have changed some but still bolt up correctly to the same places. Patrick, "THE ORIGINAL PIONEER", used a 2014 Outback/Legacy engine without much grief and inspired this whole topic of how to (cheaply) salvage an oil burning, rod throwing Forester engine disaster. Along the way folks chimed in about coil spacers, cover, bracket and sensor swaps etc. Later, others figured out the reluctor/tone wheel/plate trick for 2015+ Legacy engines and then somebody posted how to deal with TGV issues for 2017 (actually 2016 and 1/2)-2018 Legacy or Forester engines with the one piece intake manifold/rectangular ports. Gotta love em all!

Why not just get a used Forester engine instead of messing with the Legacy changes? That mostly works but remember that word (cheaply)? It turns out that LKQ and other engine recyclers are no dummies and based on the laws of supply/demand a used Forester engine will cost you about 3X $$$ over a used Legacy engine. If the cost does not bother you might consider a JDM Japanese domestic market engine. Apparently after 100,000 km Japanese car owners have to jump through hoops to keep driving the car and most cars get traded in/salvaged at that point. Kilometers being shorter than miles that means 40,000-60,000 mile used engines are available. For a price.

Subaru introduced the 2.5L FB25B non-turbo "DOHC" engine in the 2011 Forester and later used it in 2013 Legacy, replacing the venerable EJ engines used in previous years. Related 2.0L FB20 non-turbo and FA Series turbo engines as well as the newer 2019+ FB25D with direct injection also exist and should not be confused with the 2011-2019 FB25B engines [hereafter refered to as simply FB25]. Forester FB25 engines are made in Japan while those used in other vehicles such as the Legacy may be made in North America. Apparently the two factories did not implement design and manufacturing changes on the same schedule so Forester and Legacy engines can be significantly different, even for the same year. The 6th digit of the VIN vehicle identification number identifies the engine, but is year and vehicle model dependent. Which means that "VIN 6 = A", does not necessarily mean the same thing for a Forester and Legacy engine. Fortunately the specific FB25 "VIN 6" engine code is not really important here. PZEV and other emissions codes are controlled by the catalytic converter and engine computer, not the engine/long block internal components. With one exception transmissions interchange just by swapping the proper flywheel/flexplate. When present, the 4AT 4-speed automatic and CVT continously variable transmission used a conventional oil cooler in the radiator. Beginning with the 2015 Legacy and 2017 Forester, vehicles with the CVT have two additional coolant ports for a separate CVT cooler. One is on the upper/crossover water pipe assembly near the EGR exhaust gas recirculation valve and contains a secondary thermostat for the transmission warmer function while the other is on the right/passenger side of the upper oil pan. Additional changes were made for a separate/improved EGR cooler. The best bet is to ignore the separate CVT & EGR cooler stuff and reuse the Forester crossover water pipe assembly with the internal EGR cooler and without the additional coolant port then cap the remaining additional coolant port on the upper oil pan, thus staying as close as possible to the original configuration.

The 2011-2013 Forester FB25 engines lack an oil level sensor and tended to suffer from excessive oil consumption, in some cases more than a quart per 1000 miles. This resulted in a lot of thrown rods and ruined engines. Apparently there was a design or quality control issue with the pistons or oil rings. Various manufacturing changes were implemented and mostly resolved the issue by 2014. Ultimately Subaru replaced many early Forester engine short blocks under warranty. See MC-10163008-9999.pdf in the links below for details.

1. A short block is usually just the engine block with internal oil pump, crankshaft, bearing and piston assemblies installed. Everything else such as the head assembly, timing components, covers and accessories has to be moved from the old engine, which is what the Subaru dealerships did.

2. A long block is a short block with a bunch of that stuff installed. It may or may not include the valve covers, timing covers, oil pan etc.

3. A complete engine will likely include all that plus a water pump, thermostat, coils, fuel injectors and throttle body. For a used engine the wiring harness and sensors will probably still be attached. Depending on the source, accessories like the alternator, belts and tensioners may be present. Note that JDM accessories are often different from the North American versions.

The further down the above list you go the less you have to swap if everything goes right but the more likely you are to run in to compatibility issues when it does not. Even a short block can sometimes differ in the number or placement of mounting hole between years or vehicle models, but things like covers, oil pan, coils, injectors, throttle body, sensors and wiring harness are MUCH more likely to change. In general a long block is the sweet spot for swaps between different years and vehicle models. With today's CANBUS controlled vehicles, all the different computer modules talk to each other and have explicit expectations about the stuff they comunicate with. Which means do not even THINK about replacing the engine without moving the wiring harness and probably some sensors from the old engine to the donor and connecting back to the original computer(s) unless they are the exact same year, model and options. Maybe.

Things that previous Forester engine swap pioneers report:
The Forester and Legacy engine mounts are different, reuse or replace the Forester mounts. Ditto for the AC compressor bracket. When moving the wiring harness and sensors+brackets to the donor engine don't forget the sensor behind the flywheel/flexplate. A Legacy donor engine will have an oil level sensor on the upper oil pan that does not get connected to anything on a Forester. If an electrical connector on the donor engine does not match, the old sensor/part with the correct connector will usually fit in the same mounting hole/spot. If a part number changed but has the same connector it is often compatible with the superceded sensor/part and can be used instead. The forester and donor vehicle can have different transmissions as long as you install the correct flywheel/flexplate for the Forester transmission on the donor engine and allow for any donor engine coolant port differences. Replacing the water pump on a donor engine that has been sitting around is never a bad idea.

2013-2014 Legacy Donor, as above plus:
The coils and valve/rocker covers are different. Either move the rocker covers along with the coils or make spacers so the Forester coils fit the Legacy covers. The throttle bodies have different part numbers but are apparently compatible. Some people move the throttle body while others don't.

2015 Legacy Donor, as above plus:
The change from hydraulic to electric power steering deleted a pulley from the timing cover. While moving the timing cover and power steering bracket also move the timing "tone" wheels/plates that are under the cover. The "notch/bump" shape change is incompatible with the Forester sensors and the computer will throw codes P0016, P0018 otherwise. Be alert for the possibility of additional CVT coolant ports on the donor.

2011-2016 Forester Donor, as above but:
Fewer changes in different years.

2016-2019 Legacy and 2017-2018 Forester Donor:
You may have to extend parts of the wiring harness 6-8" to reach a relocated temperature sensor and EGR valve. The intake manifold changed to a one piece plastic design=(14001AC33/14001AC33A) with integrated TGV tumble generator valves that operate in the opposite direction from those of the previous plastic upper manifold=(14003AC420)/aluminum lower manifold with TGV=(14111AA000/14111AA010) design. They are not compatible with the Forester computer as is and it will throw codes P2004, P2005, P2006, P2007. The TGV is only used during cold start. TGV delete is a common turbo performance mod but not for the non-turbo FB25 engine. Some people remove the TGV butterfly plates or makes sure they are open with the actuators unplugged or employ other tricks and then ignore any codes. One of the links below discusses how to fix things to work properly and avoid codes. It requires a bit more work involving modding the wiring harness to the TGV actuators and moving the compatible sensor magnets from the TGV butterfly mechanism in the old manifold to the donor. This fix has not been verified here. YMMV. Subaru quit servicing the Forester/Legacy FB25 TGV actuators=(14120AA090 Denso 012010-6110 with bluegreen labels) at some point and instead says to replace the entire one piece plastic intake manifold assembly=(14001AC33/14001AC33A). Note that the similar FB20 Impreza TGV actuator=(Denso 012010-6111 with greener labels) is also used on some newer FB25 one piece plastic intake manifolds. The 2017-2018 Forester intake manifold=(14001AC320/14001AC321) appears to use Denso 012010-1091 actuators with blue labels.

       #v     o        o
          =   /             \   v
            |X|            *|X|=  #
           /   *                 \ 
        o                           o
     Driver       Passenger
View of TGV actuators on the intake manifold from the back of the 2011 engine while closed

The TGV actuators use reversible 12V DC motors, not steppers. The 2011 Subaru Forester service manual say to not run them for more than 10 seconds to avoid over heating. The actuator motor internal drive gear(*) is between the holes(o) on the edge farther from the electrical connector(#). The actuator internal sensor(=) is on the other edge. The actuators do not seem to need preloading or calibration at installation. There are magnets(v) mounted on the end of TGV butterfly(X) mechanism shaft. According to the 2011 Subaru Forester service manual diagrams, for this particular TGV, the actuator and butterfly assembly rotates about 75 degrees from fully open to fully closed. There appears to be a mechanical stop cast in to the TGV gear and magnet cavity, probably to prevent the thin brass butterflys from banging closed and bending over time. Also according to the 2011 Subaru Forester service manual, and as is typical for 5V Hall effect throttle type sensors, a sensor output of ~5(4.5)V DC meaning fully open occurs when the magnet(v) is rotated away from the sensor(=) and ~0(0.5)V DC meaning fully closed occurs when the magnet(v) is rotated toward the sensor(=). Unlike the TGV actuators which are removable and identical on both sides, the TGV butterfly(X) mechanism built in to the manifold is mirror image from left/right which is why the actuators mount in different orientations. Engines with the one piece intake manifold have different internal air routing for better mixing and really do need the "reversed" TGV operation. To keep the original Forester computer happy the actuator wiring harness must be modified and sensors(=)/magnets(v) adjusted to invert signals and make it so. One possibility is swapping the actuator wiring harness connections left/right so the computer *THINKS* it is moving the other, mirror image, TGV. That is what the fix linked below does. Rather than extending and crossing the wiring harness another possibility is to just swap pins 4/5 in the actuator connectors so the computer *THINKS* it is moving the TGV the other, old/split manifold, direction. People have tried just swapping pins 4/5 which reverses TGV actuator and butterfly assembly movement but it is not sufficient to avoid codes by itself. The real trick is how to deal with the sensors(=)/magnets(v). There is a spacer between the TGV butterfly shaft gear and magnet parts, it is not a washer for the nut at the end of the butterfly shaft, but 6mm ID~10mm OD washers can be used to change the spacing as needed during the mod. Hall effect sensors can use the maget North pole, South pole or both. The new magnets are longer and apparently incompatible with the original Forester computer which is why the fix substitutes the original magnets and positions them carefully. Need hardware in hand to measure stuff!

2011-2015/2016 Split plastic upper+aluminum lower manifold TGV butterfly(X) top edge closes down toward the inner side of manifold so air is forced through a gap remaining on the outside
Driver side turn shaft clockwise to close and counter-clockwise to open       Passenger side turn shaft counter-clockwise to close and clockwise to open

2016/2017-2019 One piece plastic manifold TGV butterfly(X) top edge closes down toward the outer side of manifold so air is forced through a gap remaining on the inside
Driver side turn shaft counter-clockwise to close and clockwise to open       Passenger side turn shaft clockwise to close and counter-clockwise to open

If you are doing some other FB25 engine swap this may not answer all your questions but will hopefully provide a good place to start.

Links to assorted threads and a helpful subaru technician booklet:

https://static.nhtsa.gov/odi/tsbs/2014/MC-10069730-0699.pdf

https://static.nhtsa.gov/odi/tsbs/2019/MC-10163008-9999.pdf

https://grassrootsmotorsports.com/forum/grm/the-dreaded-subaru-torque-converter-situation/92399/page1/

https://grassrootsmotorsports.com/forum/grm/subaru-fb25-engine-interchange/135572/page1/

https://www.subaruforester.org/threads/2011-fb25-engine-compatibility.771921/

https://www.subaruforester.org/threads/2012-fb25-phase-1-to-fb25-phase-2-swap-p0016-p0018-at-30mph-updated.742713/

https://www.subaruforester.org/threads/2013-forester-motor-swap-with-a-2016-legacy-motor.825831/

https://www.subaruforester.org/threads/2014-how-to-install-a-2017-engine-into-a-2011-2016-vehicle.836125/

https://www.subaruforester.org/threads/2015-to-2012-fb25-engine-interchange-solved.829413/

https://www.youtube.com/watch?v=VTSrRJU349c

Notable quotes:

Patrick

The power steering and air conditioning lines don’t need removed, just flop the power steering pump to the passenger side and ac to the left. The exhaust unbolts from the heads with 6 nuts and will hang just enough to remove the engine without disconnecting 
___

Patrick

Went to put the ac compressor on, the bracket is different.  And my buddy scrapped the old engine this afternoon. Derp, $40 mistake. 
___

Iceracer

First rule:  Never force the convertor when you install it on the transmission
___

Dustin

Got it, just had to swap the connections at the coil packs on one and three.. :) Thanks for all your help!
___

jackmonte1987

Just a quick update. We found a plug not fully connected in the harness. The motor is running perfectly fine now with no codes
___

vandervl

Turns out it was just a vacuum leak. But it also turns out the engine has rod knock, so there's that.
___

vandervl

For anybody who runs into the same issue I was having, the tone wheel had been installed incorrectly. So the engine was getting incorrect information about the crankshaft position. If anyone's interested, here's what it looked liked (it was supposed to be lined up in position B)
https://www.youtube.com/watch?v=VTSrRJU349c
___

Hpamer3 

Ultimately, I had to swap the valve covers from my new engine and put the original forester ones on so that I could run forester coils in their stock setup with matching boots.
___

rlberg444

There is a crank sensor behind the flex plate that must be swapped over from the Forester IF the one on the new engine is different.
___
 
CHayNZ

Make the TGV system work (very technical, but I did it and so can you!)
___

AWSX1686

Gotta say, it's crazy just how tight that engine was to the transmission. Seemed like the dowel pins were a lot of it though, so they'll get cleaned up real well before it goes back in. 
___

ej22

Take the radiator out before trying to get the power steering bracket off, will allow to you get at the bottom bolt straight on and not round off the nut (on the 2016 the nuts are deeper)​

Make sure to disconnect the flex plate from the torque converter! These bolts are not visible so could be an easy step to miss​

Take the intake manifold off when you are separating the flex plate from the torque converter, makes it way easier to see what you are doing​
___

Marino454

​You can get rid of the cam/crank codes by switching out the cam phaser plates under the timing cover, one has tabs and one has indents
___

SDO

BTW, you can fairly easily find out which camshaft reluctor (tone) plates you have on your engine without removing the timing chain cover. Locate the camshaft position sensors mounted on the upper left and right corners of the timing chain cover. Remove one of these sensors and then shine a light into the resulting hole. You will be able to see the edge of the camshaft plate. Use a 22mm socket to turn the crankshaft clockwise. This will turn the camshaft and you will be able to see whether the camshaft plates have notches or "tips."
___

Dizzhead

The timing cover only has mounting for 1 idler pulley because they removed the hydraulic power steering. I suppose if you are brave enough to swap timing covers it’s not impossible but take great care as to install it properly because if you don’t it will leak oil.
___

Quadraria10

The front cover must be swapped to the old design for power steering. The valve covers must be changed to use the old coils. The coolant crossover was changed to eliminate the transmission cooler hose (not used on the 4 speed trans) to the CVT cooler. I did cap the other end on the upper oil pan.
___

In reply to Skenton :

Wow.  Great collection of info.

I was about to pull the trigger on a 2016 Legacy engine from LKQ and would like to avoid that TGV complication.

Just checked the Subaru parts website.  The one-piece intake manifolds for the Legacy stayed the same from 2015 to 2019 (part number 14001AC33A) so not sure how everyone who did the 2015/2016 swaps dealt with the TGV issue with those engines.  The 2013 and 2014 engines use the two piece plastic/aluminum intake (part number 14003AC44A).  Likewise there are different head part numbers for those corresponding years which implies they are not interchangeable.

Anyone know if you can simply swap the intakes or is there a porting difference on the heads?

This is going to be a great resource for us trying to do the mental engine swap before the physical swap.  If you have actually done the swap, please please please comment for those of us still contemplating.

Thanks,

I had just started pulling the engine when Covid came to visit several members of the family. We are collectively still recovering. No joke for me at 65+ I have been doing lots of online research when too tired to do anything else on the car.

Yes the block ports are different incompatible shapes for the one piece intake vs the earlier design in addition to the TGV change in direction. They cannot be swapped with earlier engines.

The FB25B engine was built in at least two different places which were not synchronized with changes/updates. Based on success stories the Japanese built Forester engines through 2016 are pretty much drop in for 2011-2013 Foresters except for the rocker & timing covers and cooling changes while for the North American built Legacy engines that is only true for 2013-2014. In 2015 the shape of Legacy timing/reluctor wheels/plates changed, requiring swapping with the earlier engine. Some people talked about just the camshafts while others mentioned the crankshaft too. Until I get the two engines side by side with the timing covers off I am withholding judgement about what will need swapping there.

I have also seen the one piece manifold specified for 2015-2019 Legacy engines, but people who claimed to do swaps using the 2015 Legacy engine talked about the cooling & timing issues but not the manifold/TGV. Maybe there was a mid year change or some engines from Japan for certain Legacy configurations or something? That is why I want to see the donor before buying if possible. Maybe jdf60 can comment on the 2015 Legacy Donor when it arrives.

It is also why I have been looking so hard at the TGV magnet fix from the post I linked to, trying to understand it. Low milage older engines are getting harder to find so a 2016-2019 option might be good. Note, the Forester changed from the FB25B  to the FB25D in 2019 while the Legacy waited until 2020. Also, I believe one piece Forester and Legacy manifold have different part numbers for some unknown reason.

OK this is just weird. On all the Forester and Legacy FB25 intake manifold pictures I have looked at both old two piece and new one piece, the TGV actuator mounting holes were closer together on top than bottom so they looked "tilted" toward the center of the manifold. Except for one where they both "tilt" to the left.

Maybe the original 2015 Legacy intake manifold really was one piece without the TGV reversal and then got superseded with the improved design in 2016 as well as for repairs?That might explain the odd Subaru instructions to "replace the whole intake manifold" for TGV repairs.

Or maybe actuator Denso 012010-6110 and 012010-6111 are more different than I thought. Sensor location, direction?

Edit - It's probably just something silly like a misidentified turbo manifold though.

BINGO 2017-2019 Impreza 2.0L intake manifold, mystery solved - /Edit

Dunno, see pics.

Skenton said:  I had just started pulling the engine when Covid came to visit several members of the family. We are collectively still recovering. No joke for me at 65+ I have been doing lots of online research when too tired to do anything else on the car.

I started pulling the engine yesterday.  At 61+ it isn't a joke either.  Three careful hours later I am down to one mount nut (lower, driver side) away from putting on the chain and pulling the engine.  Rain and dusk forced me to stop and wait till next weekend.  I would like to order an engine this week.  Hopefully we can get resolution to the TGV issue once and for all.  I almost ordered a used one-piece intake just to play with to see if the modifications mentioned in other posts made sense.   Keep us informed on your research progress.

If anyone reading this has access to a one piece plastic manifold to open it up and take TGV pictures please speak up!

Some multimeter voltage measurement would be helpful too.

People talk about having trouble getting the engine and transmission to separate due to corrosion on the pins. I have been spraying both sides of the top of that joint with Pblaster and letting it run down and soak for a week. That I can manage to do :-)

One poor soul reported that after jacking up the transmission to get the mount bolts out of the cross member, it settled just enough to catch the very tip of the bolt on one side. It took forever for them to figure out why one side separated OK and the other would not budge.

In reply to Skenton :

I think the 2015 legacy engine I just received  today does have the 1 piece plastic manifold. I just barely had time to look it over. But it doesn't mount the same as my forester intake which has a metal riser between it and the heads.  So hopefully this won't be a huge issue like the later model swaps I've ready about. 
 

haven't had time to read through your entire post yet but I will. Thanks for that!

I sure wish I'd known where this lkq engine was coming from beforehand. These NE engines sure do get corroded up pretty bad.  Although it's fairly low mileage so hopefully the internals are clean. 

I posted a screen shot from the 2011 Forester manual about diagnosing the TGV up thread a bit. If you decide to measure voltages note that the motor is 12Vdc like the car battery but the sensor is 5Vdc. Subaru says to not run the motors for more than 10 seconds to avoid overheating them. Switching the 12V +/- lines reverses the motor direction. You can probably chop up a USB2 cable and use a meter to find the 5V wires instead of messing with 3X drycell 1.5-1.7V batteries. Note the 1K (0.5-2.0) Ohm resistor is important and electronics tend to fry and die if the 5V lines get reversed :-(

Understanding which way the 2015 TGV butterflys rotate for open and closed on each side as well as the sensor voltage for each position would really help. A picture of the TGV gear/magnet locations in each position with the actuator unbolted and removed would too. Is it like 2014 and before or 2016 and later?

Can you confirm the Denso part number for TGV actuator solenoid/motor on your 2015 Legacy motor?

In reply to Skenton :

I probably need to take off the intake anyway so I can get a pic of that and get the part numbers.  Maybe I'll work on it tomorrow. 

As I mentioned above, the one-piece intake manifolds for the Legacy stayed the same from 2015 to 2019 (part number 14001AC33A) so you will most likely be very interested in the progress of this thread.  The old intake/TGV will not bolt to the newer heads so you will need whatever fix is ultimately created.  This thread was the closest thing I found to a solution  to the TGV  issue:  https://www.subaruforester.org/threads/2014-how-to-install-a-2017-engine-into-a-2011-2016-vehicle.836125/

Another daughter's husband came down with covid today but I finally have more. energy. If tomorrow is as good I will get back to pulling my engine too. I doubt I will get as far in three hours though. :-)

Apparently I was wrong about the 2015 Legacy manifold. Despite multiple people claiming to use that engine and talking about the crank/cam timing/tone wheels needing to be swapped I do not recall anyone mentioning the one piece all plastic intake manifold and TGV until the 2016 Legacy engine.

I believe the Forester engines were made in Japan with the split upper/lower intake and original timing design through 2016. The North American made 2013-2014 Legacy engines were very similar to the Forester but apparently received some changes in 2015 that did not appear in the Forester until 2017. Maybe there was some confusion about the donor vehicle or something.

The link about moving the magnets to fix the TGV issue was for a 2017, presumably Forester, but hopefully will apply to a 2015+ Legacy engine. Once I get the 2011 engine out I will open up the TGV, take pictures and grab my digital caliper to measure the shaft etc. If another person got it to work, so can I!

In reply to Skenton :

Part number on the denso tgv is  012010-6110 for the 15 legacy.  They look identical but I can't find a part number on the forester piece. Same plug and everything. 
 

it appears that the 13 forester 2 piece would bolt onto the 15 legacy engine.  I'm not sure that it would work correctly but it does indeed fit. I noticed Some differences in plumbing for the egr. 

jdf60 said:

In reply to Skenton :

it appears that the 13 forester 2 piece would bolt onto the 15 legacy engine.  I'm not sure that it would work correctly but it does indeed fit. I noticed Some differences in plumbing for the egr. 

Can you please attach photos of the head ports and the intake ports?  The heads and one-piece intakes are said to be more rectangular and do not swap with the earlier two piece versions.  They may bolt on but they may not match flow paths.

FYI, I use the Subaru parts web to verify fitment and application of parts.  That is what told me the 2015-2019 Legacy and Outback uses the integrated one-piece intake manifold.  Very useful in the research of what year has which parts.  https://parts.subarugrapevine.net/p/Subaru_2015_Legacy-25L-CVT-4WD-Limited/Engine-Intake-Manifold/60014618/14001AC33A.html

In reply to mildensteve :

I'll try to take a pic tomorrow. Yeah it does bolt up but like I said, not sure it will work. If I remember right the '15 intake ports were a little longer and the '13 might have been more squared. But the single piece manifold did completely cover the '15 head ports. So will that small amount of mismatch make it run bad?  I'm not sure. I've run mismatched ports on Chevy engines and they ran fine. But not saying this one will.  There are some flow diverters inside the heads that look nearly identical on both years. 
 

my other option at this point if I still want to use the '15 legacy engine is to just use the short block. But I still don't know what's wrong with my forester engine. So I don't want to use it's heads necessarily. So I'd probably have to go through those heads and rework them. Turning into more work than just finding the right drop in engine.  Which I think would be the '14 legacy.  Which is selling for a lot more money. 

That is why the TGV fix via magnet swap looks so appealing. mildansteve reposted the link up a few posts.

The direction reversal can be dealt with by either swapping the TGV wiring harness left/right or probably by swapping pins 4/5 in the TGV connectors. The problem is getting the sensor open/closed signal to the computer right to avoid codes. Without hardware in hand I cannot be sure, but I think the trick is drilling out the flat indexing spot on the shaft hole in the old black magnet bracket and rotating them correctly when replacing the new white magnets. I suppose it might be possible to file the correct index slots instead of drilling a round hole.

Edit

These are almost certainly Hall effect sensors that measure the strength of the magnetic field on the sensor as the magnet rotates by. They can be designed to use the north pole, south pole or both poles of the magnet. The signal from a 5V throttle type sensor like this should vary between 0.5V and 4.5V from closed to open. What exactly the Forester computer is checking for is anybody's guess. The original poster on this topic said the new magnets were "incompatible" with the forester computer, hence the swap. Drilling out the maget mounting hole index is to allow positioning the magnets to generate a signal that keeps the computer happy while rotating the other way. It all makes sense, just need to see it it works as claimed.

It should testable with the manifold on or off the engine using a multimeter or scope, a 1K  Ohm resistor plus 5V and 12V voltages sources.

A long time ago I bought a cheap set of pin removers on fleabay similar to this picture. Makes car wiring work much easier without fighting and damaging connectors.

In reply to Skenton :

Wiring harness is completely different too. Would probably have to swap the entire Forster harness along with figuring out how to correct the tgv issue. Starting to look like I made a $600 mistake. Looking at some '14 legacy engines online they are much more similar. Same intake snd same egr amd wiring harness setup. Not sure what I'll do at this point. I don't really want to swap the wiring harness and risk not being able to make the intake/tgv work right. 

In reply to jdf60 :

I think Skenton is real close to figuring out the TGV.  The harness, along with the other parts (valve covers, timing covers, possibly cam plates, sensors, flexplate, etc.) were known to be simple mechanical swaps according to all the write-ups.  The TGV is the only mystery that will make the $600 mistake into a cheap upgrade to the Forester.  And someone figured it out already, albeit using a little black magic.  I really think a couple of wiring swaps in the connectors may do the trick.  I like the reverse polarity idea to switch the direction.  I am hoping someone else can repeat the success :)