TDI 1st Gen Tacoma Swap

[BimmerTim]

I bought my first, and so far only, Toyota back in August 2017.

A friend and I flew one-way to Seattle from Minneapolis to find a truck to drive back. I was originally after a 2015 Ford Ranger, as I really wanted a small, manual, 4wd truck that I could TDI swap. After no luck finding a nice enough Ranger we started looking at other options, with the Tacoma as a front runner. I drove quite a few, but landed on a 1998 Xtra Cab with a ton of miles on it... I have since put another 60k mi on it driving all over the country camping and off-roading with it. My last trip was to Wyoming for a week-long off-road trip through the Black Hills, Sierra Madre, Medicine Bow, Wind River, and Big Horn mountains. The 2.7L 4-cyl 3RZ-FE is nothing to write home about, but on this trip I could tell it was really starting to feel its age. The time has come to start the TDI swap.

Since I can recall I’ve wanted a small truck with 4wd, manual, and a diesel. As far as I can tell, this doesn’t exist in the US. I did find a couple of Hilux for sale in Canada, but I wasn’t sure about importing and titling at the time. Plus, with an imported engine you run the risk of being stranded if something breaks on a trip.

I have also been into European cars for 20-ish years, and have own a couple of 2000 era TDIs. That is a plentiful engine around the US, Canda, Mexico, etc. So, I found a 1999 VW Golf TDI Automatic that was no longer acceptable for the road as a donor. In hindsight I do wish I had gotten a slightly newer TDI since the ECU is not flashable in the early cars, they use solder-in chips. The automatic was intentional, because the auto came with an 11mm injection pump where the manual only came with a 10mm injection pump. Not that I plan to hotrod it much, but it does open some doors for power.

After a few years of preparation and not wanting to take apart my truck, because I use it for camping quite often, it IS finally time. I will be attempting to be more live updating this part of the process. I’ve only been working on it for a couple of weeks, so this an update that will bring us to today.

I started by pulling the 2.7 3RZ out of the engine bay to see what I’m working with.

A very dirty engine bay. I don’t have water in my workshop, so I bought one of the portable battery pressure washers that use the same battery as my lawn tools. I would say it’s very convenient, but if you’re hoping for high performance look elsewhere. For what I need, it’s perfect. I can put in a little extra elbow grease and scrubbing if it means I can clean parts up at my shop.

I have a few 1.8t engine blocks laying around, so I decided to test fit with one of those to check oil pan to diff clearance. There wasn’t any… I also wasn’t sure what angle to set the engine at, so I ended stripping the 3RZ down and setting it back in the bay.

With the 3RZ bolted back in I made some super janky transmission locating brackets.

The transmission staying in the same place as stock will ensure that drivetrain and shifter angles all stay the same. I don’t want to stress other parts by raising the engine and changing angles if I don’t have to.

Next, I wanted to see how the TDI engine fit in the space. I had read about vacuum pump clearance issues. I was worried about the FWD turbo VNT actuator location, and I wanted to see how the oil pump would clear the front diff.

All things considered, it fits pretty well.

The vacuum pump has no issue with clearance and I could put my hand between it and the firewall.

The VNT actuator, however, is a different story. The actuator sits only about 1/2in or so from the passenger mount bracket on the frame. There is no way the stock mount is going to fit there. The stock mount would be a very tight fit, but doable on the driver side, but not with A/C in the stock golf location.

I would like to get this on the road as quickly as possible so I can start finding the bugs and working them out. I have some trips planned and I don’t want to be worrying about stupid things.

I also want to use as much of the OEM Toyota and VW parts as possible. For the A/C I have two options;

• Redesign the driver mount to allow A/C pump and lines to fit, and have custom lines made. This is also not ideal, because the Toyota A/C is on the passenger side and the VW will be on the driver side. If the pump were to fail on the road you cannot route a belt to bypass the A/C pump without custom brackets and pulleys.
• Design a bracket to mount the Toyota A/C pump on the TDI block and find OEM VW serpentine parts to run the A/C separately.

I chose option 2.

With a little research I found that in Europe the Seat Leon was offered in TDI without A/C. What this does is remove the A/C pump from the main serpentine belt on the TDI, and with the added benefit of relocating the power steering pump lower.

Here is the original TDI serpentine layout.

And here is the non-A/C Seat serpentine layout.

I also found that older Audi A4 and VW Passat 1.8t came with the A/C running on a second serpentine belt with the pump mounted on the passenger side.

The secondary serpentine belt is a 5 rib belt, which is exactly what the Toyota A/C pump is. The Audi/VW also has a tensioner system I can work with and a crank pulley that has both serpentine belt spots.

Another key is that I can now leave the A/C and pump until absolute last. If I had run the A/C on the main serpentine system I would have had to figure it out before putting miles on or risk damaging the pump.

 

[BimmerTim]

My next mission really became figuring out how to mount the engine in the bay. I needed to design brackets to bolt onto the engine, remove the original brackets on the frame, and design new brackets to mount on the frame.

Lets start by 3D scanning the engine and the engine bay.

With the engine and bay scanned I can cut down on the point clouds to make the parts easier to work with and start modelling. I designed a driver side mounting bracket, and passenger side mounting bracket, and a bracket that will be welded to the frame. I made sure to keep the positions of the brackets to be welded to the frame the same from side to side. The rubber mount is the most basic, but robust mount I could think of. I couldn’t build a car without using parts from a BMW E30, so the rubber mounts are from an E30. Haha.

Tucked in there you can see the driver mount and then the passenger mount.

The passenger mount was a bit more of a pain, and I ended up with 3 revisions. I wanted to make sure that it was small enough to allow removal of the starter, which is super tight, but I also wanted it to be strong enough and minimize deflection. I performed FEA on both the driver and passenger mounts… I ended up at about 300 factor of safety before permanent deformation.

Here is a view from the back with a bunch of the scan cropped to show how the mounts work together.

Once the general designs are sorted out you have to make sure they can be fabricated. I chose to use 3/16” A36 plate for the design. Each piece can be cut and bent by SendCutSend, but I’ll have to do the welding.

Once split up into the plate parts I made drawings and uploaded them to the SendCutSend site.

There was a little back and forth with SCS, but they were in production within about a week and at my door a week after that.

I quickly got them tacked up.

Once I knew they fit I welded them out. I would make a few changes to make assembly easier in the future, such as adding some slots and tabs and chamfers for welding.

After welding they were fit up again and confirmed they didn’t warp too bad.

 

[BimmerTim]

Happy with the mount arms on the engine I turned to the engine bay. The brackets on the frame needed to be removed.

There was quite a bit of cleanup to do to remove the welds, but it went pretty quick. There is a decent amount of undercutting from the factory welds (The black “cracks”). Believe it or not, that is not from me cutting the brackets off. I only nicked the frame in one spot on the driver side. I think I might gouge them out and fill them with weld, if even just to look nicer.

I set the engine back in the bay with the trans locating bracket in place one final time. I was able to mark the location of the new brackets to be welded on the frame. I did have to make a small notch around one of the rear welds on each bracket, but they went in without a hitch.

The E30 rubber mounts fit perfect. I’m hoping they’re soft enough to keep the noise, vibration, and harshness to a minimum.

Next was to put the engine back in to verify everything fits. Then stand back and start planning the rest of the bits and bobs.

The starter is easily replaced with this slimmed down passenger mount.

I won’t be using this pan, so ignore that part. Quick undercarriage shot.

Next up will be planning out the radiator and intercooler setup. I have an idea, but I need to do a bit more work before I commit. One thing is for sure, there is a ton of room for activities up there.

 

[BimmerTim]

That is up to date.

Right now I am working on the radiator and intercooler setup. I have both on order, but the radiator is custom and won't be here until the end of April. The intercooler is also custom, but I only ordered the core, and I will make the end tanks.

I have the oil pan modifications designed and parts out for fab, so I'll post a full update with that process once it's done.

I also have parts coming for the downpipe and exhaust.

There a few things I can do while I wait for parts, so I'll update as I get things done.

 

[burpod]

holy first post on tdiclub! wow! what a job!

 

[BimmerTim]

Ha. I'm no stranger to the forum, just lurking for years. I'm not sure why I didn't register years ago. I've had a couple of tdi golfs.

 

[jmodge]

Slick job on the motor mounts. What are you running for an adapter?

 

[BimmerTim]

Slick job on the motor mounts. What are you running for an adapter?

It's a TD Conversions adapter. I went back and forth on which adapter to get, but the adjustability in this one is pretty advantageous. I liked that I was able to get the engine angle to match what it would be in a golf and keep the transmission at the stock angle as well. The thickness was also a huge help in pushing the vacuum pump far enough away from the firewall.

 

[burpod]

Ha. I'm no stranger to the forum, just lurking for years. I'm not sure why I didn't register years ago. I've had a couple of tdi golfs.

figured as much, but way to make your final appearance LOL

 

[BimmerTim]

I have a thread over on TacomaWorld with more origin story on the Tacoma as well as trip reports. I can post them here too if there is interest.

BimmerTim's Tacoma Build (tdi swap) and Trip Reports

Hey everyone, I posted a similar (the same) story in the welcome threads a while back. I kind of stalled starting a build thread, because I hit a deer...

www.tacomaworld.com

 

[jmodge]

you may be aware, the BHW exhaust manifold will bolt to the ALH and pick the turbo up and away from the engine a bit. If that’s something that’s an option for you. It sounded like you weren’t to fond of the position of your actuator

 

[BimmerTim]

you may be aware, the BHW exhaust manifold will bolt to the ALH and pick the turbo up and away from the engine a bit. If that’s something that’s an option for you. It sounded like you weren’t to fond of the position of your actuator

Thanks! I was looking at quattro tdi setups and noticed their turbos were higher. Once I got into the mount design, since I had to do something anyhow, I was able to work around it.

Really early test fitting, i.e. holding in place with my hand, seems like the Tacoma A/C pump should fit without moving, but there is still a real possibility that I do switch to a higher mounted turbo in the future.

Now I know to look for BHW turbos if I do!

 

[jimbote]

Thanks! I was looking at quattro tdi setups and noticed their turbos were higher. Once I got into the mount design, since I had to do something anyhow, I was able to work around it.

Really early test fitting, i.e. holding in place with my hand, seems like the Tacoma A/C pump should fit without moving, but there is still a real possibility that I do switch to a higher mounted turbo in the future.

Now I know to look for BHW turbos if I do!

Yeah, the BHW/AFN manifold is ideal for a tacoma or any longitudinal swap. It's what i'm using on my first gen, awesome starter clearance and frees up space below. Check out XMan for some performance BHW turbo options. Also the taco compressor fits the vw longitudinal AC bracket with a simple interfacing sub bracket. But if i had to do it over i would have just used the BHW compressor. Seems Austin Niemela used one on his first gen BHW swap with no mods other than some custom lines.

 

[jmodge]

I’m looking forward to seeing what you do with the diff and oil pan. The engineering tools you have are impressive

 

[BimmerTim]

I made two decisions with this swap that made pretty extensive oil pan modification necessary; I wanted to keep the angle of the engine the same or very similar to how it sits in the mk4 which pushes the pan to the driver side, and I wanted to keep the engine at the exact same elevation and angle as the 3rz which sits pretty low in the bay.

I started by 3D scanning the original tdi oil pan and turning it into a usable model. I added the oil pan model into the 3D scan of the bay and engine where it became even more obvious that the pan was going try existing in the same space as the diff in a very big way. If I were to just notch the pan around the diff I would lose nearly half of the oil capacity, so that wasn’t going to be a good solution for me.

I started trimming the oil pan model to fit around diff and try to add the volume into a front sump design.

Happy with this design I broke it up into smaller buildable parts that I would just weld together. Those, again, ere ordered from SendCutSend.

At this point I got the flu and didn’t want to move for a week and a half. When I finally got off the couch, I started by tacking the bottom of the sump portion of the pan together. I forgot how bad I am at TIG welding aluminum, but it went pretty well.

I was planning to weld the inside of the seams, but after attempting that I stopped. Welding the outside will be fine…

Before I can weld anymore pieces on I need to trim the pan. In order to avoid oil contamination and generally making my welds look worse than they already do, I bought a new TDI oil pan to start with.

The new pans you can buy all have provisions for an oil level sensor, which the pan I scanned did not have. It doesn’t look like it is different in any other way and it will get cut off with the mods, so I should be good to go.

 

[BimmerTim]

Taking measurements from the CAD model I transferred the important points onto the new pan. I used a marking tool that is essentially a vertical dial caliper with a carbide scribe attached.

After measuring and checking again it was time to cut…

Now I get the first look of the sump mocked up.

When I had the individual parts made I intentionally left larger flanges in a few places with the intention of marking and trimming the excess off later. One of the main bits of trimming is the back of the upper portion of the pan. You can see on one side there is a pretty big gap, which is because I used the wrong reference point when marking this piece for trimming. Luckily I was able to just trim to shift it over the other way.

With the little drain bit mocked you can see the remnants of a mistake I made trimming. I forgot that the side of the pan you see here is angled, so the cut needed to also be angled. The first mock up made that obvious to me, so I filed the cut at an angle which dropped the total height. Not a big deal, just need to goober weld in there.

There is also this bit of pan left at the back that I need to trim. I’ll be cutting it at the line shown here.

 

[BimmerTim]

I test fit the other filler pieces as well. You can see the gap from my angle snafu pretty clearly.

Before you look at the next set of pictures, please remember that I am not a welder, moreover I am not an aluminum welder. Just an engineer pretending to be a welder.

I still have to drill a hole and weld in a bung for the drain, so it’s not totally done. Overall, I’m happy with it. If I learned anything from this little side quest, it’s that I really need to practice aluminum fabrication and welding. I also warped the flange a little bit, which you can kind of see in a few of the photos, but when I test fit it onto an old 1.8t black I have it flattened without much fuss and the Hondabond will seal up real good. I “might” take it to a real machine shop and see if they can mill it a bit flatter, but that would require someone seeing my work up close and I’m not sure I’m emotionally prepared for that.

I also have this new oil pickup that I’ll modify to suit the front sump and it’s depth.

I’ll also be fitting the engine back into the bay soon, with the diff in there, so I’ll grab some clearance photos at that point as well.

 

[jmodge]

Slicker than owl $hit on a hot tin roof.

If you intend on climbing steep hills I’ll throw an idea at you.
A friend talked me into this years ago on an off-road truck. It was a flat track oil pan for a SBC. It had a large sump with hinged baffles. Oil could flow in but not out, so the oil pickup was always submerged.
I didn’t have to fab it like you are doing, but I’m sure you get the idea if it fits your requirements.