ALH into C5 Allroad

[mr.mindless]

I was hoping a search could prevent me from posting a possible teaser thread, but it looks like almost all Allroad swaps posted here are BHW. I have several ALH to choose from and that's my preference.

I've got a 6MT 2.7T Allroad in decent shape with lots of powertrain issues. It needs a clutch, cats, yet more oil leaks looked at, and due to getting under 20mpg when I do 50 miles/day, it mostly sits outside of snowstorms.

I've got 3 ALH cars to pick from for a donor, the one I've had the longest and the most likely donor is a jetta wagon. Great black leather interior and a strong runner with 17/22 turbo and 768 nozzles but lots of body rust and failing paint, a falling head liner, an apparently bent rear beam (lots of camber and even & balanced inner shoulder tire wear)...

If memory serves, the ALH runs on an EDC15 ecu and the Allroad 2.7 on an ME7.1 ecu
Pinouts for a bench flash harness are very different, I haven't looked deeper than that but I'm sure differences are vast. Kinda shocking when they're plug compatible and power isn't even on the same pins.

I suspect the reason most Allroad swaps are BEW/BHW is computer simplicity? I don't want to lose the convenience items like climate control and a functional dash. I'm still on air too, so functional level control is important. I don't much care about IMMO. I do need the right VIN reported and monitors showing ready for plug-in inspection too.

The closest search results I found is some mention of another early swap (with no link given) needing to run both computers to keep the body side happy.

 

[Zak99b5]

In New York the motor swapped into a car has to be the same model year or newer, I do believe.

 

[Zak99b5]

Oh wait I see the Audi and Jetta are both '03s now.

 

[d24tdi]

I suspect the reason most Allroad swaps are BEW/BHW is computer simplicity? I don't want to lose the convenience items like climate control and a functional dash. I'm still on air too, so functional level control is important. I don't much care about IMMO. I do need the right VIN reported and monitors showing ready for plug-in inspection too.

The closest search results I found is some mention of another early swap (with no link given) needing to run both computers to keep the body side happy.

I would say the reason you see the BHW as the most popular swap into allroads is not so much to do with the computer configuration and more about these two factors:
1) It has greater power/torque from the factory, and more potential for further increase, than the 1.9L options which is a benefit in the heavy AWD allroad, and
2) More importantly the BHW engine comes out of a B5.5 Passat which shares a great deal of common architecture with the C5 platform. Therefore many parts that you would have to figure out from scratch using an ALH or other engine just bolt in, thus giving you a major head start on getting the whole thing together (especially if you have a complete B5.5 donor car and not just the engine). Things like the wiring harness, cooling system parts, power steering plumbing, A/C, fuel system, etc are much closer to plug and play. Saves time, and also has the benefit of proven solutions, ease of maintenance/parts sourcing, and a more factory-correct look and function.

The ALH was only ever available in transverse platform vehicles. Not that it cannot be adapted, but there would be a lot of hard work to do with the details. Accessories, belt drive, plumbing, wiring all would involve reinventing the wheel. I know at least one ALH has been done into a C5 allroad. There have probably been other setups as well. Someone did a CR engine into a C5 sedan. But with any of those, you are just taking on a much larger endeavor vs using something like a BHW from a B5.5, or a similar Euro PD130 longitudinal engine like AWX (IIRC?) as some others have done.

That said, the ALH has its advantages too -- mainly in general robustness and sheer commonness/ease of finding one and keeping it on the road -- and some folks just don't like the PD engines as much. I personally am not the biggest fan myself. So if the ALH is what you like then there's nothing that would stop you from doing it. Software hurdles could probably be overcome if that is your main concern. I rounded up everything to slip a BHW into my 01 allroad then eventually decided to go with a Euro 2.5 TDI V6 instead, which I picked up this summer and will probably install sometime in the next 20 years.

 

[PickleRick]

I'd have to second the BHW power and torque for being the choice for the all road. There's also the year of manufacturing for many areas, a motor must be same year or newer than the vehicle it's going in for emissions purposes.


The BHW with just a tune you drop in the all road and go. The ALH, you need to have her modified pretty good to get to that level, and then you likely should get an egt gauge for that heavy vehicle to keep an eye on hills, heavy footed driving.

 

[[486]]

you've got a manual trans, so I'd probably just run both ECUs at the same time
See if the edc15 guy will talk to the allroad cluster through the can bus to run your tach and engine temperature (it probably will) and let er rip while ignoring the pile of trouble codes it'll cause in the ME7.1 guy, not having an engine connected to it and all

doubt they'd make it so the air ride, air bags, ccm stuff, and abs stop working when the engine is all manner of gone
but germans don't surprise me when they do such things

thought for a while about sticking a 1.6D into either one of them or a 4wd passat wagon
never got around to it
Wouldn't be afraid of the PD motors though, they're really uncommon around here but they can make good power with relatively little effort
BEW did get the biggest injector bodies they made, just with the smallest nozzles.

 

[d24tdi]

What makes you think that would be the way to go? I have to say that I don't believe there would be any need or reason to retain the gasser ECU. There are plenty of BHW swapped B5, B6, B7, and C5 cars out there running happily on the diesel ECU alone. With the right software the BHW ECU can be coded to play correctly with Audi climate control. ABS is no issues. I don't believe the air suspension ties into engine ECU either, at least not in any way that matters or would justify the extra mess and complexity of keeping the Motronic box as a placeholder.

I went pretty far down the road of BHW into my allroad before changing directions and I never saw anything that made me conclude retaining any of the gasser electronics would make any sense at all. I still don't plan to do it with my AFB 2.5L V6 swap either.

A 1.6D into a C5 allroad? Gotta be kidding LOL. Hard to imagine a more goofy mismatch, a crude and weak old engine in a heavy cushy sophisticated AWD car built for triple digit speeds. The car would be so badly compromised for anything but low-speed use that it wouldn't even begin to be worth the work. The old 1.6 was a great engine in a Mk1 or Mk2.... not much else.

 

[bbob203]

All these boomers are gonna tell you it won’t work because ALH wasn’t available in longitudinal format but it’s simple to run it as longitudinal. BHW TOP coolant pipe fits if you remove the ALH vacuum ball. The BHW bottom coolant pipe also works just have to trim a few of the fuel line labs off and weld a tab to secure it to the block. Use 1.8t Passat motor mount brackets and an ALH Non Ac Alt/accessory/pump bracket from euro ALH Style motor. For the mounts the accessory bracket has to be trimmed a slight bit. There are several people running ALH as longitudinal. Fee free to PM me I’m doing ALH swaps into Passat b5.5s which is essentially the same platform. Ve is superior fuel system and ALH bottom end is capable of plenty of easy power if you get a better cam such as R2 cams out of Finland(can be found on Facebook) and Run newer style turbo such as GTD1752vrk or GTB2056vzk. They run lower Exhaust manifold pressures which is what kills ALHs.

 

[PickleRick]

Plenty of guys running the ALH in Suzuki's, jeeps and Toyotas in a longitudinal application. The ALH is probably the most popular TDI swap in north America, probably 2nd most popular swap behind the Cummins 4bt.

My issue with the ALH is the power, costs a lot to get comparable power you get with just a tune on the BHW motor plus the BHW comes with all the brackets and accessories you need for many longitudinal swaps. My Toyota 4 runner TDI conversion wouldn't have been possible if it wasn't for all the ALH swaps before mine. Budget is always an issue with any of my conversions.


And it was the boomers who designed and built the first TDI adapters.

 

[d24tdi]

All these boomers are gonna tell you it won’t work because ALH wasn’t available in longitudinal format but it’s simple to run it as longitudinal.

Nobody said it won't work, just that the BHW is easier, which it is. I'm no boomer myself, not that I can see why that would matter....? But nobody likes to do unnecessary work regardless of what generation you wanna put them in

The ALH can most certainly be done and it does have its advantages, plus there are matters of simple preference, where some folks just like them better or trust them more, certainly get that. All else equal I probably like the old VE engines over the PD engines myself too. If I were choosing engines in a Mk4 I'd rather run an ALH than a BEW. But the BHW into an Audi longitudinal platform is just a turnkey setup in a way that the ALH is not. It's not only cooling system plumbing that is better. The BHW has an engine driven fan that works with no effort, the wiring harness and fuel lines and vacuum tubing and charge air plumbing and PS plumbing all run to the right places in the engine bay without making any changes.... etc. Less work, and easier to make it look factory.

By all means you can run an ALH too, and there are parts out there that would help to put it together, but you're cobbling together lots of pieces from different cars -- 1.8T gassers, BHW TDI, ALH TDI, maybe some Euro longitudinal AHU/AFN stuff if you want factory look, and undoubtedly a few ebay or parts store items. A lot more effort rounding up all the stuff and putting together the puzzle. By comparison, for a BHW swap all you need is one donor Passat with a dead trans, maybe a set of fresh motor mounts, maybe a BSM delete kit, and a timing set. The car gives you *everything* else.... every piece of plumbing, every wire, every bracket, every nut and bolt.

The PD fuel system is extremely reliable and capable. Really the PD engines' only big issues, cam wear and glow plug selection and the BS decisions, are solvable or at least easily manageable. So they have their advantages too. Remember that other than the cylinder head and the BS module, the rest of the motor is made of the same tough stuff. They are all good setups. I'm not trying to argue that there's a right/wrong way, just that the BHW is less work to plug in there.

 

[oilhammer]

Ditto what d24tdi said. Plus, the C5s already left the factory with an 8v PD 4 cyl in them, the AWX and AVP, which are 1.9L PD130 engines. So, the factory already did this, the PD136 BHW is essentially just a PD130 with a slightly larger bore. Oddly, the 2.0L PD in the C5 is a 16v engine, so not as much in common with the BHW, and is not much more powerful.

There were no factory longitudinal late type VE TDI 4 cyl, which I always found strange. The longitudinal cars went straight from the old style VE engines (like an AHU) to the PDs, which are ALL the new style.

Other than the balance shaft drive upgrade, my BHW I purchased new just crossed 1/4 million miles and hasn't had one peep of troubles. I service a lot of PDs, they really are perfectly fine, I'm not sure why so many people are scared of them other than just ignorance I guess. Correct oil and filters and the camshafts last plenty long, they make great power and respond very well to tuning.... shoot, the BRM can be graced with a whopping 50% increase in output with software alone (thanks to that lovely full frontal intercooler!), and they'll happily run along like that indefinitely. I know, I service a bunch of those, too. The BHW just started out with more power, but it is also saddled with a bigger heavier car, although mine has had RC1 for a while now... it makes my ALHs feel lethargic in comparison.

 

[d24tdi]

Yeah exactly. The fact that VAG built PD engined C5 chassis cars themselves creates a big advantage. The same advantage could exist in theory for the old 028 block motors perhaps, except for the fact that those are pretty lame compared to the PD as far as power potential, plus the longitudinal 028 TDI models never came here so there are no donors. Whereas dead B5.5 donors exist in plenty.

Although the ALH swap into any B5 or C5 era car is still pretty easy in the grand scheme of engine conversions -- still bolts in using factory stuff, as opposed to swapping into Toyotas and whatnot -- the reality is, the easiest way to drop an ALH into a C5 or similar would be ..... to use a long list of BHW or PD130 parts. You will want BHW manifolds or at least the exhaust manifold, BHW downpipe, BHW engine mounts and brackets, various BHW cooling system parts, BHW oil pan and snub mount bracket, BHW power steering pressure hose, BHW A/C compressor and lines, BHW charge air plumbing parts........ etc.

Yeah, in the case of some of those (oil pan, mount brackets, some AC and PS stuff), you could also source 1.8T parts. But the rest of it will have to be BHW or Euro longitudinal PD parts, or pieces you fab yourself. Plus of course your ALH engine and related parts would be needed. So if you're gonna have to scrounge all that, why not instead just get a complete B5.5 TDI donor car which would come with all of it probably for less than the sum of getting the adaptation pieces a la carte? Plus would provide a plug-and-play engine with a stronger bottom end, bigger oil cooler, better pistons, more displacement, an accessory drive layout that fits much better (which cannot be achieved with an ALH due to the IP), and a stock fuel system and turbo that can make serious reliable hp just with a tune that would take much more work with an ALH.

All that said, there is definitely a place for doing something different even if it's more work. Respect for anyone who makes that choice and takes on the extra creative effort with eyes open. But, if the argument is that the ALH swap would be "just as easy" as BHW into the OP's Allroad, I think that does not hold water.

I guess the only technical advantage for ALH might be the rear of the crankshaft having a full depth pilot bearing recess which the BHW crank does not. But that seems to have been proved to be a non-issue in the many, many manual swapped B5.5 cars on the road.