B4 Passat TDI Swap

[PalmettoDub]

Hello all, I did a quick search on here and could only find items for sale for what I'm about to put up for discussion. I have a VR6 B4 Passat that the auto trans pooped out and I have a fully functional and driveable 05 TDI Beetle 5 speed that I want to swap into said Passat. Who can help with do's and don'ts. I am aware of having to turn of the immobilizer and such. I am sure it isn't bolt in either. So.... Let her rip, tater chip!!!

 

[IndigoBlueWagon]

Neither engine nor transmission will bolt up. If you want to swap a TDI into a B4 you're better off finding a B4 or A3 donor.

 

[oilhammer]

You can bolt them in, but it isn't as straightforward as the mountings are not the same. Lots of people have put later type engines in the earlier cars, though. Whitbread even put one in with twin turbos, and when the FWD wasn't getting all the power to the ground, he put a Haldex AWD system in it! So yeah, it can be done, but it won't be straightforward.

Good news is, VAG tends to have multiple uses for everything, so lots of stuff can go in places it was not originally found if you can get the correct collection of off the shelf parts. For instance, your B4 has a rear/right (sort of under the expansion valve area) engine mount. The BEW engine from your NB has no mount there.... but the block has the threaded holes for one.

There are also some aftermarket swap kits for this sort of thing. While they may not often mention "TDI" in particular, the second generation 1.8t engine (like the AWP, for instance) is the same family as your BEW. And your B4's basic arrangement is mostly the same as an A2, A3, B3 car.

Like this one:

Fabless 4-Cyl Complete Mount Kit (OEM Position) - VW MK2 Golf / Jetta

The Fabless 4-Cyl Complete Mount Kit for the VW MK2 & Corrado can be used a direct replacement for MK2 & Corrado factory 4-cylinder engine mounts or they can be used to swap in a 1.8T or another 4-cylinder engine listed below. Compatible with the 02a/02J 5 speed transmission.Our mounts are...

www.urotuning.com

 

[PalmettoDub]

Wow, that is impressive. I am aware that the Passat shared items like the pedals and such from the corrado. But didnt put it together for other shared parts. Super cool info. I appreciate you.

 

[oilhammer]

You can think of the B4 as being mostly just a facelifted B3, in the same manner as the A3 is mostly a facelifted A2. And they all share a common basic design underpinning which originated with the A2 Golf in 1985 (the Corrado is mostly A2).

The main points being the commonality of things like subframe/axle mount locations, engine/trans mount locations, steering/pedal box mount locations, shifter box locations, etc. There is an amazing amount of parts swapping available across those cars.

The A4 car, however, the 4th generation Golf, upon which your NB is based, is a very different layout. Most notably the engine/trans and subframe/axle mounting points, but there are lots of other differences too. So bridging those two engineering groups can be more work that fitting something from a similar car in there. As IBW mentioned.

 

[PalmettoDub]

I am capable of making and fabbing so if I can get the main support done, I can mod after that. I assume axles will need to be made to attach to the B4 spindles?

 

[oilhammer]

The VR6 B4 should already have the larger stuff at the outside, 5 lugs and all. So you should be good there.

 

[jhax]

I would be very surprised if the PD motor did not have threaded holes on the rear passenger side of the block in order to mount the rear passenger motor mount bracket. That is the only mount bracket that would need to be replaced so the motor could be mounted on the subframe. The trans mount bracket from the 02a should bolt to the 02j and the front mount may need to be replaced with something older.

 

[CasaEd]

If you use the 5 speed gearbox, then you can use all the Tdi engine and gearbox mountings, as this is the way I fitted the PD into my B3 wagon.

 

[PalmettoDub]

If you use the 5 speed gearbox, then you can use all the Tdi engine and gearbox mountings, as this is the way I fitted the PD into my B3 wagon.

Any chance you could chat or text? would love to pick your brain. 302-258-7376

 

[CasaEd]

Unfortunately I live on the wrong side of the pond, but you can ask your questions here and I will try to answer them for you

 

[PalmettoDub]

Unfortunately I live on the wrong side of the pond, but you can ask your questions here and I will try to answer them for you

Totally understand! How much kidding is needed to bolt the BEW engine and trans into the B4? I hear mixed replies all over that most of the mounts are there but since mine is a VR based car, I may need a major mount mod like Oilhammer mentioned above.

 

[CasaEd]

If you use the 5spd gearbox it's straight forward, I fitted a 0.7 5th gear, but the diff ratio is 3.389:1, when I finally get around to pulling the engine & Box on my B4 for major engine & gearbox mods I will use the CTN in the B3 with the 0.7 gear out of the other box. Another good gearbox we get over here is coded ASD, another long gearbox, ideal for PD conversions. I have never looked at a VR car, not sure they even imported that into Portugal, but if the subframe is the same as a TDi then you will just need the mountings for the engine block because maybe the gearbox mounts are the same.

 

[jhax]

Subframe and therefore motor mounts are the same between the VR6 Passat and TDI Passat. VR6 rear block mount is a bit thicker/taller than the TDI one because the VR6 is a heavier motor.

 

[oilhammer]

The subframes all have different part numbers, so they are not the same. ETKA lists four different ones for the North American B4: VR6 manual, VR6 automatic, 4 cyl (gas or diesel) manual, and 4 cyl automatic (which for us was only the ABA gas).

What specifically is different, I do not know. The front carrier is also a different part number. The VR6 cars also have different control arms, and they are L/R. All the 4 cyl cars use a different arm, and they are the same L/R.

From what I remember, the B3, B4, A3, and Corrado (which was mostly A2) VR6 cars had to get different suspension geometry for caster to make them handle correctly. Which makes sense. Because not only is the VR6 lump substantially HEAVIER than any of the 4 cyl engines, but it is also canted FORWARD for some reason, instead of the 15 degree rearward slant of the 4 cyl engines. That nose heavy attribute, which admittedly is the least pronounced in the larger Passats, is still there. VR6 A3 Golfs are actually not that great to drive in twisting turning conditions. They handle pretty poorly, really.

 

[jhax]

The more you know.