2nd Gen Tacoma BHW Swap

Braddman

Active member
Joined
Jun 25, 2019
Location
SW Ontario
TDI
2006 Audi A4 BHW 2.0 TDI, 2005 Toyota Tacoma BHW TDI Swap
I picked up a mint condition 2005 Toyota Tacoma back in October. The body has been repainted, the frame was replaced a year ago under warranty, new rear axle, leaf springs, control arms, brake lines, wheel bearing and the truck is on 35” tires with a 2” lift. 225,000km on the truck, the engine ran mint, a week after I bought the truck I decided the engine it doesn’t have that satisfying knock and fuel economy that a TDI has. After I bought the truck I did some research and found out no one makes an adapter kit for a 2005 or newer Tacoma. Well I guess I will be the first one to do it. I finally got around to posting this on the forum.




The patient to be operated on, a 2005 Toyota Tacoma with the 4.0L V6 with 6 speed manual bought for $15K.





1 week later, pulling the old Toyota 4.0L V6 1GR-FE gasoline engine out of the Tacoma. I sold the engine for $1900




Removing the 2.0L TDI engine code BHW out of the donor car which is a 2005 Passat with a bad torque converter purchased for $1000.




Now, building the adapter plate. I bought a 17” x 17” x 2” plate of 6061 aluminum, $500. I chose aluminum because it is way easier to machine then steel. I had to go with 2” thick plate because I needed to make a 2 piece flywheel adapter since the Toyota flywheel is an 8 bolt, the TDI is a 6 bolt and the bolt holes overlap. I’m also glad a went with a 2” thick plate because it gives me just enough clearance between the tandem pump and the firewall. I started by boring a hole so the adapter plate would be a slip fit on the Toyota 1GR-FE crank.




Adapter plate on the Toyota engine




This is one of the most important steps to building a custom adapter plate. The dowel holes need to be drilled at precisely the correct location relative to the crank . To do this I put 10mm pull dowels in the dowels holes on the engine, I then screwed M6 transfer screws into the dowels. Next I slide the plate on the crank and marked the dowel locations.




After drilling out and reaming the center punched dowels holes on my milling machine I put the transmission bell housing on the adapter plate. This allowed me to use transfer punches to mark the bolt hole locations for the transmission and scribe the bell housing outline on the adapter plate. The transmission was conveniently already in pieces at this time because I had to replace a broken 5/6 shift fork.




Bell housing holes drilled and tapped.




The hole I bored for the starter on milling machine. After 2 hours of cutting on a friends bandsaw I had a rough outline of the adapter plate.




I indicated the existing crank locating hole then bored the hole to a slip fit on the TDI crank.




This is a closeup of using pull dowels and transfer screws to transfer the dowels holes. I’m amazed that this technique actually worked, after drilling and reaming the dowel slip fit on my mill the whole adapter plate slide on the crank and dowels nicely. That is an accuracy of a couple thousands of an inch!




Drilling lots of holes to make an outline so I can jig saw the center out of the plate.




The TDI bolt holes drilled and counterbored. I used M12 transfer screws on the TDI engine to mark the bolt hole locations.




Trimming the adapter by plunging with an end mill every .05”. It worked, just took a while.




The pack man ghost shape is not just for a joke I needed the ghost legs so I could access the oil pan bolts without removing the adapter plate from the engine.




Machining the flywheel adapter on my lathe. The boss has been machined to be a slip fit on the Toyota flywheel.




After flipping around the adapter, I indicated the previously machined face. I used my 4 jaw chuck so I can move the plate around to indicate the bore.




Machining the other side ofthe flywheel adapter. On one of the plates the bore was machined to be a slip fit on the TDI crank and on the other plate the bore was a slip fit on the mating adapter plate to keep the flywheel centred on the crank.




The bell housing adapter plate bolted to the TDI.
 
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Braddman

Active member
Joined
Jun 25, 2019
Location
SW Ontario
TDI
2006 Audi A4 BHW 2.0 TDI, 2005 Toyota Tacoma BHW TDI Swap

Drilling, tapping and counterboring the flywheel side adapter plate.




Flycutting the face of the bell housing adapter to set the correct starter protrusion.





Completed adapter kit only took 2 weeks to build, and $500 in aluminum, it’s a shame the beautiful kit will be hidden between the engine and transmission.






Anyone ever seen a TDI with the starter on the oil filter side. Thank you VW for casting clearance into the block so I have just enough room to mount the Toyota starter on this side.




Flywheel adapter bolted to the BHW.




The adapter kit and flywheel bolted on the the engine. You can also see how I will have to move the oil filter housing up and out of the way of the starter.





I had to use an oil pan from an ALH because I needed more clearance between the front differential and the oil pan. The ALH oil pan is about 3” shallower than the BHW oil pan. Even with the ALH oil pan I still had to raise the front of the engine up about 1” from level. It also turnout that the bellhousing bolt pattern on the ALH oil pan is different the the BHW oil pan so I had drill new holes in my adapter plate.




Replacing the timing belt and deleting the problematic balance shaft module.




I had to change the oil pickup from the 1.8T oil pickup that came with the balance shaft deleted kit to an ALH oil pickup because the 1.8T pickup sticks down too low. The longer oil pickup is from an ALH.




Windage tray installed.




Timing belt kit installed.




Drilling new holes for the ALH oil pan.







The 2 steel flanges tacked together with the oil filter housing sitting in place to clear the starter.




My first attempt at building an oil filter housing relocation manifold. I welded this manifold 3 times and it stilled leaked so i decided to built one out of billet aluminum.




$400 2 1/4” x 5 1/2” x 8 1/2” block of 6061 aluminum. I chopped the corner off that I didn’t need.
 

Braddman

Active member
Joined
Jun 25, 2019
Location
SW Ontario
TDI
2006 Audi A4 BHW 2.0 TDI, 2005 Toyota Tacoma BHW TDI Swap

I indicated the steel adapter by setting the angle on my angle plate, then rotating adapter. I scribed a line, then clamped the aluminum block in place up against the line.




Transfer punching and drilling holes for the filter housing.




I lined up the drill bit with the steel manifold by tilting and rotating the

manifold. I then mounted the aluminum block, spotted the holes with an endmill and drilled them out.




Drilling and tapping to relocate the oil pressure sensor so it clears the dipstick better.




Milling clearance for the starter.




Counterboring the mounting holes.




Indicating the steel manifold with a plate on top. I installed a bolt in each of the manifold into the t-slot so I had a repeatable location with the scribed lines and the angle set on the angle plate.




Milling the face after it was indicated.




Milling clearance so I can tighten this bolt with a ball end allen key.




Fly cutting the gasket surfaces.




Here you can see the slots I milled on the block mating surface. This is to replicate the porting channels that are on the oil filter housing.





The completed oil filter relocation manifold





Before and after mounting the manifold. In the picture I had just cut myself on a broken spring loaded fuel line clamp.




Facing the flywheel on my lathe.





Both adapters mounted on the TDI.




For my clutch I bought a stage 2 Underdog Racing Development clutch which is rated 440 ft/lbs.




The flywheel all mounted, I had to machine some material off of the face where the starter mounts to the bell housing adapter to get the right amount of starter gear engagement.
 
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Braddman

Active member
Joined
Jun 25, 2019
Location
SW Ontario
TDI
2006 Audi A4 BHW 2.0 TDI, 2005 Toyota Tacoma BHW TDI Swap



Custom driver side mount. I used the BHW rubber motor mounts and mounted them to the original motor mount plates on the frame.






Custom passenger side motor mounts.







Clutch installed and ready to go into the truck.

A couple pictures of the the broken 5/6 gear shift fork from the Toyota R-A60. I also had to replace some of the 5 gear parts.






The transmission during reassembly.




The BHW engine bolted up the Toyota R-A60 6 speed transmission.





The BHW sitting inside the Tacoma, it fits pretty good with lots of room.




I removed the fuel filler neck and using a die grinder, ground the opening up to 1” diameter because gasoline filler nozzles are 7/8” and diesel fillers nozzles are 15/16”.




Heater core and coolant to oil cooler pipe shortened and modified.




Upper rad pipe with the outlet fitting flipped 90 degrees.
 

Braddman

Active member
Joined
Jun 25, 2019
Location
SW Ontario
TDI
2006 Audi A4 BHW 2.0 TDI, 2005 Toyota Tacoma BHW TDI Swap

Intercooler mounting brackets fabricated and mounted.





Intercooler and intake pipes all welded up and installed.





I used a K&N cold air intake for the Tacoma and built my own turbo intake pipe.








To roll beads on the intake pipes I machined a set of dies on the lathe. I then mounted the dies in the lathes and rotated the chuck by hand.





Custom 3” down pipe with brace to mount the pipe to the transmission. The exhaust is 304 stainless steel up to the tailpipe.




Down pipe mounted and bolted to flex joint and mid pipe.




Custom 3” mid pipe with exhaust hangers and 6” long flex joint. The intake a exhaust pipe cost me $1600.




I used an MBRP 3” tailpipe because it saved me some work but it turns out it is either 409 or aluminized steel. If it does rot out I will build one out of 304 stainless.






I had previously stripped the Toyota engine harness down to just the 4wd actuators, transmission sensors, fuel pump relay and alternator charging wires. Working on installing new split loom on the toyota harness and replacing all the brittle shielding on the TDI harness with new split loom.






When I started the engine for the first time I noticed the intake sounded really poppy which only got worse after taking the truck for a test drive. The truck was gutless and at full load around 3k sounded like a gasoline engine at the rev limiter. I took a look at the camshaft and the exhaust lifter for #3 cylinder had wore through the top of the lifter. I replaced the cam with a new kit from @Franko6 because it has upgraded cam bearings. Now the intake sounds normal.
 
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Braddman

Active member
Joined
Jun 25, 2019
Location
SW Ontario
TDI
2006 Audi A4 BHW 2.0 TDI, 2005 Toyota Tacoma BHW TDI Swap




I have put 18,000km on the truck so far, and I’ve been getting around 9l/100km with the truck and it works awesome. Before October of 2021 I was running an immobilizer delete and stock BHW tune and the horsepower was decent. Now I have a stage 2 BHW tune from Malone, 175hp and 305lb/ft of torque this makes a big difference when hauling trailers over 3000lbs. I love the torque, in 1st gear low range at idle the engine has enough torque to crawl up 45° hills offroad. The build took me 4 1/2 months and about 1000 hours. The truck is pretty much done I just have some small things left to do like get the gauges working, tidy up the ECU wiring and mount the electric rad fan.
 
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Braddman

Active member
Joined
Jun 25, 2019
Location
SW Ontario
TDI
2006 Audi A4 BHW 2.0 TDI, 2005 Toyota Tacoma BHW TDI Swap
To figure out the wiring I bought a yearly subscription for the Passat and Tacoma repair manuals on alldatadiy.com and printed all the powertrain management diagrams. I labeled all the important Tacoma connectors on the Passat diagrams and vice versa. I also highlighted the important and unnecessary wires. This gives me a great wiring diagram for troubleshooting electrical issues. I am using 2 separate OBD2 ports because I was afraid that if I joined both ports I might have communication issues since Toyota and VW use 2 different CAN Bus protocols.

When I went to test the 4WD, the lights where flashing indicating a system malfunction. I ended up having to permanently leave a cheap OBD2 reader plugged into the Toyota OBD2 port so the 4WD works. I think what is happening is the 4WD Control Module needs to see some sort of CAN Bus signal since I no longer have the Tacoma ECU in the truck.


I built a bracket to mount the BHW ECU in the same location as the original Tacoma ECU. I retained the original BHW engine harness to body connector mounting bracket and mounted it beside the ECU. I also added an additional connector to that mounting bracket for connections between the striped down Toyota harness and the BHW engine harness.

I will add more pictures in a few weeks after I receive my CAN2DASH from Fast Forward Automotive. The CAN2DASH will be used to make my tachometer, temperature gauge, glow plug and check engine light functional. I am currently just using a Scan Gauge to monitor my RPM and coolant temp.
 
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AGTDI

Member
Joined
Jan 22, 2021
Location
AG CA
TDI
2002 Jetta Wagon
Nice build.
Impressive craftsmanship and solid looking truck. Perfect for running through the trails.
 

iwannajettatdi

Veteran Member
Joined
Jun 17, 2003
Location
Salem, OR
TDI
2015 Brilliant Black Audi Q5 3.0TDI, 2014 Tempest Blue metallic Jetta Sportwagen TDI, 2002 Blue Eurovan Weekender BHW TDI
Solid work, Braddman. That looks like a fun build/swap.
 

50harleyrider

Veteran Member
Joined
Jun 16, 2007
Location
charleston,wv
TDI
2005 B5.5 TDI/geared BSM, BV43A turbo,stage 2 TDTUNING. 2005 5sp manual passat tdi stage 2 tdtuning,BSM delete. 2015 Passat TDI 6sp manual.
Could you share some of your wiring issues and results? I'm planning a BHW into an 03 Explorer Sport Trac. Did you utilize the passat harness and OBD2 port so you can access through VCDS? My plan is to have two ports
 

HoneyBadger

Well-known member
Joined
Dec 25, 2012
Location
San Jose, CA
TDI
'02 Jetta 5 spd, 03 jetta auto, future ALH Ranger
Great work! I wish I had thought to use a lathe as a bead roller. That's much nicer than my plier made beads. I'll have to do that next time...

9l/100km isn't much more than the truck got with the gas engine is it? My quick google search says that's about 26mpg. But I'm sure you have tons more power for that fuel economy.
 

TurboABA

Veteran Member
Joined
Jul 24, 2010
Location
Kitchener, ON
TDI
RIP-2010 Jetta 6spd 2014 Touareg Execline
Awesome.... do a tacobox setup and it will crawl up any grade that it can get traction on.
 

Braddman

Active member
Joined
Jun 25, 2019
Location
SW Ontario
TDI
2006 Audi A4 BHW 2.0 TDI, 2005 Toyota Tacoma BHW TDI Swap
@50harleyrider, I edited post #7 to include more information about wiring my truck.

@HoneyBadger, the lathe worked great. According to Fuelly.com those trucks with the 4.0L V6 average 13.4L/100km (17.5mpg), so a fair bit of improved fuel economy.

@TurboABA, I would love to install a Tacobox but they are really expensive.
 

50harleyrider

Veteran Member
Joined
Jun 16, 2007
Location
charleston,wv
TDI
2005 B5.5 TDI/geared BSM, BV43A turbo,stage 2 TDTUNING. 2005 5sp manual passat tdi stage 2 tdtuning,BSM delete. 2015 Passat TDI 6sp manual.
Terrific build. Stirs memories of my Mercedes OM606 into F150 build. You could probably sell the plans of your plate to TDadapters. I'm sure they would like to have it if they don't offer one yet. Keep on posting....
 

PickleRick

Veteran Member
Joined
Nov 29, 2017
Location
Greenville sc
TDI
05 GLS BHW sedan 5 speed conversion. BHW Carver SantaCruz in progress
What thermostat housing did you use? On my 4runner conversion the bhw housing points way too close to the engine mount.

I was considering the alh housing as I want to ditch the quick disconnect houses anyway.

Was unsure if it would work with bhw accessors.
 

Braddman

Active member
Joined
Jun 25, 2019
Location
SW Ontario
TDI
2006 Audi A4 BHW 2.0 TDI, 2005 Toyota Tacoma BHW TDI Swap
I am using the BHW thermostat housing. I actually built the motor mounts before I even tried installing the thermostat housing. As luck had it I ended up with between 1/8” and 1/4” of clearance. The lower rad hose happens to also be the perfect shape I just cut the factory quick connect off of the rad side and connected a union between the Tacoma lower rad hose and the BHW one.
I’m not sure if the ALH thermostat housing will clear the alternator, it might but it will be really close. Are you able to modify your motor mount?
 

PickleRick

Veteran Member
Joined
Nov 29, 2017
Location
Greenville sc
TDI
05 GLS BHW sedan 5 speed conversion. BHW Carver SantaCruz in progress
Not really, would cause clearance issues with shifter to move forward and fire wall clearance issues moved back.

I'm installing in an 87 4 runner with r150f.
 

PickleRick

Veteran Member
Joined
Nov 29, 2017
Location
Greenville sc
TDI
05 GLS BHW sedan 5 speed conversion. BHW Carver SantaCruz in progress


The 1.8t thermostat housing looks promising.
 

Braddman

Active member
Joined
Jun 25, 2019
Location
SW Ontario
TDI
2006 Audi A4 BHW 2.0 TDI, 2005 Toyota Tacoma BHW TDI Swap
That thermostat housing looks pretty much the same as BEW one. The only problem you might run into is the thermostat housing might hit the BHW coolant hard pipe that runs to the back of the head because it takes a sharp 90° turn out of the block. You might have to change the hard pipe to one from a BEW, BRM or 1.8T.
 

PickleRick

Veteran Member
Joined
Nov 29, 2017
Location
Greenville sc
TDI
05 GLS BHW sedan 5 speed conversion. BHW Carver SantaCruz in progress
Thank you got the info, I'm going to order the 1.8t upgrade kit which includes quick disconnect to barbed hose conversion parts. It's cheap Chinese crap but for less than 50 shipped its worth it to mock up swaps to see what fits.
 
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