convert TDI B5 to stick, or convert gas B5 stick to TDI??

midnightoil

Veteran Member
Joined
Feb 18, 2013
Location
Minnesota
TDI
researching for a TDI highway driver and occasional tow pig
Two strategies, similar outcome...

I'm thinking out loud again, a few years back I originally researched things and for some reason got fixated on the idea that a Jetta might be better than a Passat for me, I think because TDI versions just came already with a stick and TDI and just being ready to drive without messing about seemed best.

A few years later now i'm back to considering things like minitruck swaps and i'm wondering why I haven't given more attention to the Passat since it might be a better interim vehicle than the Jetta for me.

Does it make more sense to try and convert an automatic, TDI, Passat to have a stick shift?

Or does it make more sense to take a stick shifted Passat with a gas engine, and swap a TDI in there?


One thing I notice is that i'm a little confused by all the engine variations seemingly in the Passat (AFN/AVB/AWX/AVF/AJM/ATJ), but no listing of the ALH which is my preferred version. That alone makes me wonder if an ALH swap into it might be better. Since I see the BHW is also available in later models of the B5.5 that would also seem to be a direct bolt in if I went for some kind of ALH/BHW hybrid engine using the block too instead of just the internals, with the ALH head. (yes i'm aware 90% of people will say the BHW is a better engine, it probably is, I have specific reasons for wanting to experiment with ALH instead including lower replacement cost of those experiments screw up)


There's even the option to swap both engine and trans obviously. Is the standard 5 speed in the Passat with a 4 cyl different for the diesel vs the gas? If not that might be a reason.
 

GoFaster

Moderator at Large
Joined
Jun 16, 1999
Location
Brampton, Ontario, Canada
TDI
2006 Jetta TDI
Yes, the transmission's internal gearing is different depending on the engine. AFAIK the various manual swaps that have been done were either using transmissions from Europe, or were using gas engine transmissions and "dealing with it". V6 gas engine gearing might not be too far off. I don't know if the bell housing is compatible.

VW sold TWO 1998 B5 Passats with an ALH engine before deciding that it wasn't a good idea for this market (underpowered). One of them is on this board and has become a hotrodded project vehicle. I don't think we know where the other one is.

These cars are getting hard to find in good shape around here.

It makes no "sense" to "convert" any vehicle compared to buying something else that suits your needs as original equipment. A "conversion" of a Mk4 Jetta from the explosion prone automatic to manual might make sense after the transmission explodes if the rest of the car is in good shape. Maybe. It's getting rarer that the rest of the car is in good enough shape to avoid spending $1000 to fix a $1000 car.
 

PickleRick

Veteran Member
Joined
Nov 29, 2017
Location
Greenville sc
TDI
05 GLS BHW sedan 5 speed conversion. BHW Carver SantaCruz in progress
The only thing ill add..if using a gas passat transmission you need to use one from a v6 (dvz) and there is another v6 code i cannot remember. It's great around town, not so great cruising down the hwy past 75mph.

The v6 subframe will not interchange with the 4 cylinder vw engines(gas and diesel) the 1.8t and bhw diesel 04/05 use the same subframe.

Im not sure if a b5 subframe will fit on a b5.5. Plenty of junker passats out there to find one on the cheap.

Bhw has much more power potential than the alh. Delete the balance shaft and tune the ecu for 170hp/300 ft lbs torque. You'd need to build the hell out of an alh for that power.
 

Windex

Top Post Dawg
Joined
Apr 1, 2006
Location
Cambridge
TDI
05 B5V 01E FRF
Easiest way is to convert an auto BHW to a manual - there are enough of them out there with bad trannies, that they are relatively cheap.
 

midnightoil

Veteran Member
Joined
Feb 18, 2013
Location
Minnesota
TDI
researching for a TDI highway driver and occasional tow pig
If it's just an interm vehicle, why not keep the auto?
Maybe the simplest answer to avoid some of the apparent growing frustration with some segments of the board is to just say "some of us are going to be working on car and fabrication projects ANYWAYS" because we've just decided that, long term, is something that were willing to invest the time and money to do. Some of us just have a need to be messing about with wrenches and welders at some point.

And that some of those projects might have the potential to save money so at times we combine the two to see if they might work as an unexpected positive. Or we start doing related research wondering how many other potential projects we might tackle if the first works.
 
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PickleRick

Veteran Member
Joined
Nov 29, 2017
Location
Greenville sc
TDI
05 GLS BHW sedan 5 speed conversion. BHW Carver SantaCruz in progress
I have a a few running bhw passats with bad transmissions. My sedan runs great but is cramped on space a lot thanks to work and hobbies.

If i found a mint b5 or b5.5 gasser wagon for a couple hundred bucks id jump on it.

Like midnight oil says, I'm gonna be wrenching on something any way.
 

NMDieselExplorer

Active member
Joined
Mar 25, 2017
Location
New Mexico
TDI
B5.5 Passat TDI Wagon 6 speed ELN conversion
My two cents is this: The only way it would make sense to swap a Passat gasser to TDI engine is if you are going to do it with a 4 motion Passat gasser. Otherwise the easiest swap is to convert a B5.5 Passat TDI from automatic to manual transmission.

I have driven a TDI converted to 5 speed manual using a 4 cylinder 1.8T transmission, which is a low budget swap since those gearboxes are a dime a dozen-the gearing made it so that cruising on the highway at 75 meant the engine was spinning at a rather high 3,000 RPM-not ideal for the BHW turbo diesel engine which was very buzzy at that RPM and may wear the engine out prematurely. With the correct transmission that engine spins at about 2400-2600 at 75mph, but not the end of the world to have it run at 3,000 RPM either. The one I drove consistently returned 42 mpg and had 260,000 miles on it and was still going strong.

I have also driven a TDI wagon converted to Euro diesel 5 speed EEN transmission and one converted to Euro 6 speed, which I still have. The 6 speed is the ELN transmission and it is very nice on the highway. It has a ring & pinion of 3.875 and 6th gear of .561 I believe. The engine runs about 2500 RPM at 80 mph-very quiet, relaxed, and returns 45 mpg highway.

BTW-subframe doesn't make a difference between cars that originally had a 1.8T or V6 or TDI engine-the transmission cases are all the same. The only thing that is different is the mount bracket on the transmission. The TDI and V6 subframes are the same. You just need a transmission mount bracket from a car with a V6 engine in order to mount the transmission to the mount on a TDI Passat subframe.

Also, swapping the automatic transmission controls to a manual in a TDI Passat that originally came with automatic transmission is really straight forward. You just have to add the clutch pedal, clutch hydraulics, and clutch switches to the existing pedal cluster bracket under the dash, which you can completely unbolt from the firewall. And swapping the automatic transmission shifter unit and box to a manual shifter unit and box is extremely simple, especially with the transmission removed from the car. Its a direct bolt-in swap. The only slightly complicated part is wiring in the clutch pedal switch to the ECU, which is really easy too.

This guy at Quality German Auto Parts has some Euro gearboxes in stock: http://www.qualitygermanautoparts.com/index.php?p=p1407518329
 
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DeliveryValve

Veteran Member
Joined
Mar 27, 2007
Location
Western US
TDI
Passat GLS Wagon

midnightoil

Veteran Member
Joined
Feb 18, 2013
Location
Minnesota
TDI
researching for a TDI highway driver and occasional tow pig
Easiest way is to convert an auto BHW to a manual - there are enough of them out there with bad trannies, that they are relatively cheap.
Yeah this logic is actually starting to convert me... I know I dont want an auto, cuz they die, so maybe I just find one with an already dead auto and tow it home, esp if going to a stick sounds like mostly a bolt in. (separate from if there are computer issues but were talking about going to a tune anyways which I thought chips remove immobilizer crap)


VW sold TWO 1998 B5 Passats with an ALH engine before deciding that it wasn't a good idea for this market (underpowered).

It makes no "sense" to "convert" any vehicle compared to buying something else that suits your needs as original equipment.
That may be, but i've spent my life driving some fairly slow vehicles - my first car was 0-60 in 20 seconds. If it gets me there and back at 50mpg i'm pretty happy - I just view the Passat as an oversized Jetta with more room and a little more stability for hauling a trailer probably due to sized up suspension/brakes. That said i'm just trying to see if I should be equally open to Passats as Jettas even if one comes with an auto. Esp since the death rate of autos may create a buying opportunity.

I don't want to drive a slow vehicle forever - I still ask about performance because it's a safety issue with a heavy trailer to some degree - but I can get by at first and don't have to instantly jump to a tune.

If the conversion is not an excessive amount of work OR amounts to only a marginal addition to "things that were going to be done anyways" i'm okay with it. Sometimes what you want is not available as OEM - like a stick shift TDI 4motion wagon. :p


The v6 subframe will not interchange with the 4 cylinder vw engines(gas and diesel) the 1.8t and bhw diesel 04/05 use the same subframe.

Im not sure if a b5 subframe will fit on a b5.5. Plenty of junker passats out there to find one on the cheap.

Bhw has much more power potential than the alh.
So basically if I went the engine swap route i'd have to start with a 1.8L turbo and convert only to the BHW diesel. (or I assume a BHW block with ALH head hybrid if for some reason that was my fixation) Also fitting an ALH using an older B5 subframe to a B5.5 chassis is an unknown and unverified if it would work, so if I was determined to go ALH I might have to stick to earlier B5 models. (where I assume the ALH just bolts in place of the normal gas 4cyls? Fact checking here) This is making me think yes just a trans swap may be easier than worrying about an engine swap.

A BHW isn't out of the question, I just got interested in ALH's so much because of the reputation of running better on waste oil - but I recently found out about some european company claiming success in running high pressure common rails on it as well, so that might skew me towards the simplicity of going straight BHW instead like you say.
 
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PickleRick

Veteran Member
Joined
Nov 29, 2017
Location
Greenville sc
TDI
05 GLS BHW sedan 5 speed conversion. BHW Carver SantaCruz in progress
If you're determined to run wvo you probably want another engine.


I see 300d wagons all the time for less than 2000 bucks and they run for ages on properly cleaned and heated wvo, wmo etc. A 300d wagon would tow some good weight...no speedster and mpgs lack compared to a tdi


If you're into a a truck old military or civilian 6.2 will also do the trick. The injection pump will not last as long on wvo but keep a spare, after a few failures you'll know the warning signs.

The 4bt and 6bt as well as isuzu 4bd series motors like wvo just fine but all those are heavy and $$$$

Stick with a motor that has cheap injectors and injection pump. Old 6.9 and old international 7.3 work too.

You will eventually have a fuel system issue as the fuel is only as reliable as your source and you're cleaning technique. I once looked into running wvo on one of my diesel conversions but the prep work would be like having a 2nd job. I ran wmo from my shop for years, sticking with a max of 25% wmo to 75% diesel ratio.

I filtered it down to about 5 microns, used magnets in the bottoms of the storage jugs and finally let it sit for a week for all soft metals to settle before pumping out the top 80% of the storage container, disposing of what was left in the bottom 20% of the container. I found about 10% RUG helped the sludge in the wmo settle very quickly as well as thin it enough to not heat during the warm months. I did not run wmo mix in the winter, only when temps never went below 60. I also changed fuel filters every 5k. I did have an inline glow plug heater in my fuel filter housing but found i didn't ever need to use it. Ive heard of 100% wmo fuels but i didnt want to get greedy and coke my rings.

We used to sell wmo from our shop, now we must pay to dispose of it. Now i burn it for heat in the shop but it still must be cleaned however at 40 microns it doesn't take nearly as long and i dont worry about a little water contamination or sludge/metal particles.
 

GoFaster

Moderator at Large
Joined
Jun 16, 1999
Location
Brampton, Ontario, Canada
TDI
2006 Jetta TDI
Keep in mind that the BHW (original 4 cylinder TDI engine in Passat) is the one with the balance shaft drive chain issue. There's a kit to convert it to gear drive, which you should do on all of these if you want them to last. The BHW balance shaft issue is covered elsewhere on these forums.

This might be another reason for one of these cars being sold off cheaply.
 

NMDieselExplorer

Active member
Joined
Mar 25, 2017
Location
New Mexico
TDI
B5.5 Passat TDI Wagon 6 speed ELN conversion
Waste Vegetable Oil is a disaster in the making IMO. The triglycerides left in the oil will always lead to coked rings and premature blow-by. If you want to run WVO best way to do it is to build an esterification reactor and convert it to biodiesel. The process is simple and biodiesel won't ruin your engine.

Putting an ALH in a B5/B5.5 is imminently doable. Requires changes to the exhaust manifold and turbocharger and some work on the A/C hoses/compressor location. I think some people have found success using a BHW exhaust manifold and turbo setup.

BTW, as I stated before, the subframes on the TDI and 4 cylinder gassers with manual transmissions are not the same. Its the 4 cylinder gasser with manual transmission that has the odd ball subframe. The difference is on the transmission mount, I think the passenger side mount.

The 1.8T with a 5 speed manual transmission used a weird transmission bracket and a different kind of mount than on the V6 and TDI cars and any of the cars with automatic transmissions. That's why the TDI subframe is the same as the v6 subframe-because the TDI came only with an automatic and all cars with automatics, regardless of engine, used the same subframe which was the same subframe as V6 cars with manual transmission. Again, as I stated previously, you can put any 5 speed manual into either subframe. Its the mount bracket that is different. The transmission cases are all the same and you can bolt either a bracket from a 1.8T manual transmission or V6 manual transmission depending on which subframe is in the car.

If you were to put a BHW into a car that came with a 1.8T and manual transmission, you wouldn't have to change the subframe as its the way the transmission is mounted that is different-the engine mounts are identical on all the B5 and C5 subframes.

I may be a "Newbie" on this goofy forum, but I have been a VW/Audi/Porsche/Ferrari/Maserati technician since 1997. Been following the TDI Club since 2001, but never felt the need to jump in as a lot of the advice is nonsense or opinion by very opinionated people.
 
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imo000

Top Post Dawg
Joined
Dec 13, 2005
Location
Cambridge
TDI
2009 M-B ML320 Diesel & '05 Passat TDI Manual 5-Speed
Nah, it's the driver side transmission mount that needs to be swapped out.
 
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