Another 1.8T A4 Quattro to TDI - Lots of Questions

Hey everybody. I just got the bad news from my insurance company and they're going to write off my darling '03 ALH Golf. Sad day. But that has me looking for what comes next! I've always had a soft spot for the A4 wagon (especially with Quattro) but I can't go without my diesel fix.

Right now I'm trying to gather as much information about swapping a 2.0T TDI engine from an '04/5 Passat (that's a BHW right?) into an '03 Audi A4 1.8T Quattro wagon. Both are available locally for me which is a huge bonus.Price for the engine is ~$950 (I'll aim for less), sounds like it has everything but the transmission (so probably no clutch), and it has "around 200km on the engine". I'm assuming they mean 200 000km.

My plan is to work on the motor and aquire parts for it through the winter and enjoy the 1.8T for a bit (while crying at the gas pumps). I'd like to: BSM delete and replace timing belt, swap to the AWM 1.8T oil pan for the level sensor and block turbo oil return, keep stock turbo & injectors, clean the intake manifold if it needs it (just did that on my ALH) and maybe an EGR delete. I just want something that works, I don't need a coal-rolling powerhouse right now (though I know I'll really want that eventually).



I've read and reread through as many other threads over the past few days as I possibly could before posting, but I still have sooooo many questions.

First off, can someone clarify the platforms of these two cars. I believe the Passat engine would be from a B5.5 and the A4 would be a B6, but what differences does that actually make? I believe the mounts are direct bolt on, and it's only really the wiring that makes it difficult right? Oh and the fuel pump. I'll probaby just add a FPR and then run the loop back into the tank like I believe GoremanX ended up doing.

Second, from GoremanX's posts early on, it seems very likely that the A4's differentials are all 3.899 final drive from the factory right? What then is the smart choice for a matching transmission? I assume the gearbox for the 1.8T will be too short. I'm getting lost between all the 01A's, 01E, and now recently I saw something about an 01X. I'm not picky about 5 or 6 speed, that'd be more about price. What I'd like is a direct bolt-on for the motor and into the A4, use the stock DMF from the 2.0T to save syncros and vibes, and have tall enough gears to not run out of revs and keep things efficient. So what are my options? It sounds like Franz is the go-to on this front if I need supply

Third, QuickTD's thread ended with him recommending an AWX EDC15P ECU, AWX wiring harness, and even the AWX manifold. Most seem pretty cheap on eBay. The result sounded like a much more simplified swap. He mentioned having to find a left-hand drive harness, are they generally going to be for right-hand drive models? Also, is the manifold swap that important? Is tuning the EDC15P necessary for a stock motor or is that only for different turbo/injector combos? Is it possible to use the stock 1.8T side mount intercooler with either the stock 2.0T manifold or this AWX one?

QuickTD's thread also mentions having to relocate engine accessories to the left side using a whole bunch of parts (BPW, BRM, AMB, and ALH are all involved), but I can't find anyone else that had to do this? So what's up there?



There's probably more I'm forgetting to ask but this will get the ball rolling! If you have any advice to add that I didn't ask about, feel free to leave that too. I know need as much information as possible. Thanks a bunch for reading all that!

Get a pre-rolled Diesel - there is an Audi wagon Diesel for sale pretty close by: https://www.kijiji.ca/v-cars-trucks/vernon/1996-audi-a6-2-5-tdi-diesel-quattro-avant-wagon-6-speed-manual/1387938835?enableSearchNavigationFlag=true

Long story short, if you are going to do the swap, use a V6 transmission for the better gearing, but the 1.8T car to get the necessary parts for AC and mounts.

As for wiring, get it custom done as no matter what you are going to have some head scratching going from gasoline to Diesel. The ECU's software is going to need to be customized to make it play nice with the car as well too.

See my signature and contact me. I'm in PG.

If you have the ability to import, it's much easier since these cars are getting older and cheaper. You can soon bring in 2004's!

TDIMeister said:

See my signature and contact me. I'm in PG.

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PG: Prince George? I spent a couple summers based around there. Tree planting. 92K trees in those two summers, by hand. The pulp plants in and around PG certainly add a certain aroma, don't they?

Have you seen this listing? http://forums.tdiclub.com/showthread.php?t=493592 This is very reasonably priced, already here and registered.

Hasenwerk said:

Get a pre-rolled Diesel - there is an Audi wagon Diesel for sale pretty close by: https://www.kijiji.ca/v-cars-trucks/vernon/1996-audi-a6-2-5-tdi-diesel-quattro-avant-wagon-6-speed-manual/1387938835?enableSearchNavigationFlag=true
Long story short, if you are going to do the swap, use a V6 transmission for the better gearing, but the 1.8T car to get the necessary parts for AC and mounts.
As for wiring, get it custom done as no matter what you are going to have some head scratching going from gasoline to Diesel. The ECU's software is going to need to be customized to make it play nice with the car as well too.

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I saw that posting! Pretty unique vehicle around these parts. Too bad the A6 is bigger than I'd like (and older). Definitely a good tip about the wiring

TDIMeister said:

See my signature and contact me. I'm in PG.

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Hey TDIMeister. Importing a car is definitely something I could be interested in! Just haven't quite figured out the logistics. Travelling out there to purchase sounds awesome... and very expensive. It also seems that all the importers around here are focused on the JDM or high-end Euro market. Having difficulty finding someone who can do the dirty work for me

Uberhare said:

If you have the ability to import, it's much easier since these cars are getting older and cheaper. You can soon bring in 2004's!

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Like what I said above to TDIMeister, that would be really cool! Having a completely factory build definitely has it's benefits

QuickTD said:

I used the awx harness and ecu since it plays nice with the cars electronics. The ABS, airbags and HVAC modules in the B6 audi will integrate smoothly with the AWX electronics. The AWX ECU will also operate the variable speed cooling fan based on AC condenser pressure and engine temperature. The BHW ECU will not do this. The AWX manifold was used due to the fact that the AWX uses vacuum anti shudder and EGR. If you were to delete these, you could use a BHW manifold with EGR blockoffs and a "race pipe". I wanted an anti shudder valve for protection from runaway, and for $60, I got one.
The stock intercooler will work just fine for stock power. I am running an aftermarket B7 dual intercooler setup with a 2056 toureg turbo.
The stock AWX tuning will run but not real well. They need a bit more advance in the bottom end (IQ's less than 20mg/stroke) to run cleanly. Slight differences in injectors I assume? You will need to delete the immo as the European ECU's use a different immo version and cannot be matched to the north American cluster. I used the 1.8T cluster with a set of European guage faces and re-scaled the tach by modifying the EEprom dump of the 1.8T cluster.
Not relocate, but leave them where they are. The B6 1.8T mounts all the accessories on the left and drives them from one belt. BHW mounts the AC on the right and uses a separate belt to drive it. To avoid sourcing new AC compressor, lines and mounts I just got a bracket from a B7 audi with a BPW. Cheaper and easier. The BHW compressor will probably fit, but is a pressure cycling type. The north American B6 HVAC uses an electronic variable displacement type compressor. You can change the climate control head to an earlier European TDI unit and use the pressure cycling type compressor, but you'll also need the rad support, an older AVF ECU and wire in fan control relays from a passat so you can run the engine driven and auxiliary electric fans. Again, I took the path of least resistance. The BRM alternator was the same physically as A BHW unit, I had it lying around and it was nearly new, so on it went. The ALH crank pulley was used since it was 6 groove and was heavier than the 1.8T unit, it was also just lying around.

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Okay that helps soooo much! I'm fairly certain you covered all of that in your thread, but for some reason it just made way more sense to me this time.
I didn't realize anti-shudder was related to runaway and that seems like a really cost effective way to get added functionality in the swap. I've got a lot to learn on the tuning side, but that's some great baseline info to work with. The fact that you can re-scale the tach just in software is super handy, I was considering sourcing a euro cluster but it's good to know that isn't as essential.
Ooohh okay that cool so its a clean way keep things in stock (on the car) locations then. So if the BHW compressor is a pressure cycling type and that requires all that additional equipment, you're saying you ditched that and just remounted the compressor from the 1.8T (which is the electronic variable displacement type) onto the BHW with the help of the B7 bracket, right? That's neat
As for the crank pully, if you swapped that for a 6-grove, does that mean all the accessory pullies also have to be swapped for 6-groove variants? or is that a stupid question?
Thanks so much for sharing your knowledge!!

mogly said:

PG: Prince George? I spent a couple summers based around there. Tree planting. 92K trees in those two summers, by hand. The pulp plants in and around PG certainly add a certain aroma, don't they?
Have you seen this listing? http://forums.tdiclub.com/showthread.php?t=493592 This is very reasonably priced, already here and registered.

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Whoa that's the first imported one I've seen in Canada! If it was a standard Golf I'd be all over it, the Mk4 wagons *never* really looked good in my mind. But thanks for sharing!

QuickTD said:

Anti-shudder just closes off the air and kills the engine when you turn off the key. When you are tuning on the ragged edge, its a good idea to keep it in place, just in case...

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Right that totally makes sense. So I'm assuming then that the BHW doesn't use vacuum for this function anymore (I know my ALH does) and that's what necessitated the need for the AWX manifold and respective EGR once the ECU was also changed over from the stock system.

QuickTD said:

To rescale the tach you need a program called "vag eeprom programmer" it was available as a free download on most of the chip tuning sites a few years ago. It uses a standard KKL cable available on ebay and allows the modification of eeprom files on bosch RB4 clusters (among others). Handy tool.

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Awesome info to have. Got the cable handy, so I'll have to dig for the software. Knowing its the Bosch RB4 cluster clarified my initial search tons! Looks there should be enough explicit info out there for me to try my hand at changing addresses with at least a modicum of confidence

QuickTD said:

Yes, The B7 BPW TDI bracket mounts the accessories in the same locations as the 1.8T, so all your lines fit. You will need to put a 6 groove pulley on the BHW alternator.The 1.8T alternator won't fit the bracket. The other 1.8T accessories already have 6 groove pulleys and bolt right on. The 1.8T crank pulley will fit and line up just fine, but an ALH pulley has a heavier damper, so I used it.

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Okay perfect. Totally understand your reasoning behind the choices you made now! And am likely to do the same haha


I'm trying not to get to far ahead of myself, but I've got some more questions now . I see you went the route of the TDI-geared 01A 5 speed from Franz, is the best place to contact him here? or does he have a website/store? Mad props on the custom milled flywheel by the way, that's badass

Also, for the LHD wiring harness, do you have any contact info from where you got yours? I'm assuming that a majority of the harnesses for sale online are for RHD vehicles (though it's unspecified) and that lengthening the ECU plug (if that's even all it is) would be quite the undertaking

QuickTD said:

Frans' company is dutch auto parts. He has a website. Best to email him, address is on his website.
I got mine from a member here. I assume he purchased it for a project but never got to it. He just had the one. The LHD harness is actually too long. It enters the rain tray at the same location as the RHD harness then crosses over to the ECU box located on the on the RH side for RHD models. The LHD harness goes directly to the ECU box on the LH side. I don't think they are particularly rare, just none available when I was buying, just lots of RHD stuff in the UK...
Check ebay in LHD European countries. I get a lot of good deals from Lithuania, they seem to post items on a variety of ebay sites, UK, germany etc. Always fast and reliable shipping, always good parts.

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Thank you so much! I know I'll have a million more questions once I get it into it, but you've been so helpful already.
Step 1 has been completed! Yesterday I sealed the deal on this beauty:





2005 6-speed manual w/ 250000 kilometers on the clock (good thing I don't care much for the engine). The car was a trade in from a single owner from a fancy neighborhood (Capilano for my fellow Metro-Vancouverites), they seem to have taken good care of it. One or two scrapes on the outside, door dent on the passenger side.
Interior is generally gorgeous but the driver's heated seat doesn't seem to work. And this morning it seems the hatch didn't register as closed on my way to work, but I can cancel the warning and it never dings so it's not a huge worry.
Think I got a sweet deal
Now to find a motor!

Time to kickstart this thread again! To restate my goal, I just want to get everything working, I'm not concerned about power output. At least not yet


So the destination hasn't changed, but how I'm choosing to get there has. Instead of going with the Passat 2.0 TDI (deal fell through, haven't found another local one in months) I've decided to purchase and import a AWX/AVF 1.9TDI from Frans!

After pouring over every thread I could find, I was still unsure about how compatible the 1.8T and 1.9TDI systems are. So the main order is for the longblock, intake manifold and EGR, exhaust manifold, turbo, engine mounts, engine loom and ecu, intercooler and piping, radiator hoses, alternator, and air filter box and piping.

From there I've also added the diesel metric gauge cluster (convenience), the european starter, the downpipe, and a new OEM 240mm DMF and clutch. I forgot about the in tank lift pump, so I've just emailed Frans asking about adding that.

It was an expensive bill but I'm reeaaally hoping this will make the swap as easy as possible. It's the biggest mechanical project I've ever undertaken and while I am nervous, I'm mostly excited!



With the engine and related accessories hopefully on it's way over soon, I've got a bit of time to prepare the additional parts for the swap.

First and foremost is a timing belt, tensioner, and water pump change. Is the BHW or BEW kit interchangeable with the AWX/AVF? I can find BHW kits in North America, but it seems anything related to the PD130 has to come from over seas (understandable).

I'm also interested in retaining the oil level sensor from my 1.8T, is it easier to drill and tap the existing oil pan, or should I source another oil pan from a 1.8T and just block the turbo return line?

Anything else that I'm forgetting but should be considering?

Engine and some accessories have arrived from the Netherlands! It seems there was a bit of a mix up however and my shipment was missing some very important parts (ie. flywheel/clutch, ECU, etc). I just got the notification that another package is on its way, so hopefully that will be rectified quickly.

I've got a potentially noob question for you all, where is the VIN stamped into the engine block on the PD130?

I found AWX232758 (that's from memory, I'll check to make sure when I get home) punched in on top of the rear flange where the bell housing bolts on, as well as a bunch of part numbers in the various castings. But I haven't found anything that resembles a VIN. There's a sticker on the back side of the block with a barcode, but it's too dirty/old/worn to pull anything off of it. The timing belt cover has no sticker on it.

EDIT: Frans has let me know that the engine is from a 2003 A4 with approximately 264,000 kilometres on it. He couldn't give me the donor VIN, because it came from a parts vehicle? Not sure why that is, but that means I'm still figuring out what I need for my timing belt/tensioner. I'll try to pop the timing cover and see if I can find some part numbers to reference instead

This thread is missing both pictures and progress. Luckily I can provide a bit of both right now!

Like I said earlier, engine and some parts arrived from Franz in a crate. I'm not sure how I'd pictured the packaging, but it was impressive! And from actual ship date to receiving date was a wicked fast 4 days



Since then I've continued to gather some parts and tools. Most of the rest of my order from Frans has come in. I ended up having to order my timing belt kit from Darkside Developments because I couldn't find a North American equivalent with the hydraulic damper setup for the belt tensioner. I wasn't aware this setup was only for the earlier years (01-02?). Really wish I had the later setup just so the next timing belt wouldn't be a $400 job again!



As I've been getting the lay of the land with this engine and cleaning it (the pallet was sopping wet and dripping with coolant/oil/diesel when it arrived) I've noticed a few differences from what I was expecting. When QuickTD made the switch to the AWX setup in his, he noted the harness was setup for PWM fan control and and RCV type AC compressor. I'm not sure about the compressor yet, but I can tell you for sure that my engine is equipped with the viscous fan and likely isn't wired to use my existing variable electric fans from the 1.8T.

Additionally, while swapping the wiring harness from the existing RHD unit to the LHD version Frans sent me, I noticed that the connector to the solenoid on the vacuum damper (reservoir?) is different (filled in corner prevents connection) and there is a missing 3 or 4-pin connector on the main trunk near the bell housing. Not yet sure what that would be for at the moment.
Today I got to clean out the intake manifold. It wasn't too dirty, but I figured it was a good opportunity. On my ALH I bough a second one and just swapped them, but here I decided to dig deep and find whatever redneck I had in me!



Good fun, a little sketchy, but decently effective! Since I already had an order started with Darkside, I decided to add in the 51mm racepipe/EGR delete and a few metres of silicone vacuum hose to replace the old stuff.
Timing tools and parts came in today and I'm hoping to get a chance to replace that tomorrow. Apparently setting the tension properly is a real pain, so we'll see how that goes!

Part of the fun (read: struggle) of having an EU engine is finding local equivalent/same parts from engines that were sold here. I've spent countless hours on 7zap comparing fiches... it's brutal. I'm sure there tons more to learn and compare but for now at least I've found the AWX shares the pilot needle bearing with the BHW (04 Passat) and it shares glowplugs and crank pulley bolts with the BEW (04 Golf).

I'll try to take more pictures as I go!

I´ll be watching this. Since i´m putting a AVF(just a AWX with 6 speed) in a 2.5 TDI Allroad, all EU market... if you´ll need any help, im glad to help if i can...

I didn´t start my swap yet, but i´m forseeing some common problems already... despite being diesel to diesel, unlike petrol to diesel like you.

But i have to convert from viscous to eletric fan, need a lift pump, since the allroad doesn´t have one, only a "swirl" one(since it´s a Quattro, 2 tanks), the AC may work different also, and a few other problems. "can-bus" probably...

I´ll keep an eye on this to see how you manage, good luck.

groundscraper said:

But i have to convert from viscous to eletric fan, need a lift pump, since the allroad doesn´t have one, only a "swirl" one(since it´s a Quattro, 2 tanks), the AC may work different also, and a few other problems. "can-bus" probably...

I´ll keep an eye on this to see how you manage, good luck.

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Welcome here! I've heard AllRoads can be tougher to work on, so good luck!

I'm already running into more problems than I'd considered! In my months of research and planning I either didn't notice or forgot that the European TDI's mounted the A/C pump on the right side of the car (same as Passat BHW TDI) where North American gas cars have it mounted higher and on the left side. If I want to use my car's compressor (which I think might be the same as the supplied AWX one) I'll either need to extend the A/C lines, or I'll have to relocate the compressor with the BPW (B7) accessory bracket, change my crank pulley to a 6-groove one (ALH) change my alternator pulley to a 6-groove one, and convert from viscous fan to electric.

This is the exact same cross road QuickTD came to! The A/C line extension seems simpler intially, but it's not something I've ever worked on before. What is all involved in the viscous-electric conversion? If I go that route I'll also need to source a few more parts before I start removing the engine from my car, which is an unfortunate slow down...

I wish i'd seen this post earlier. WHen I converted my AVF-01E wagon years ago I opted to convert the TB tensioner to the BHW style stud unit for exactly the reasons you've noted. Good thing is that you can easily do it at next TB exchange.

Today was a real beauty so I tried to get some work done.

With my Amazon-supplied tool kit, and Darkside Developments cambelt kit on hand, first thing I did was replace that. Previous worker sealed the water pump in with Black RTV-like sealant. The bolts were pretty glued in and required the impact driver. Once that was replaced and the area was cleaned up a bit it was time for reinstallation. It took about 3 tries to set the tension at the proper 4mm gap after cranking the engine around. I had to adjust the then tensioner to about 5.5mm gap, then tightened the tensioner bolt to the 20nm + 45 degrees. That seemed to settle it nicely at a slightly loose 4mm gap, well within the 3-5mm range. The tensioner stud wasn't included in the kit, so I guess that doesn't have to be replaced?



After that I started looking closer at the two wiring harnesses to see if anything else was different. Barring the last image, these connectors are all found on the lead that travels up the right side of the engine past the intake manifold. I kept flipping which way I held the connectors, sorry!
The first image is the connector for the vacuum damper solenoid I mentioned yesterday. Left plug is LHD harness, right plug is RHD harness. The grey plug on the left has the upper left corner filled in, and won't connect to the solenoid on the engine.



The second image shows two 5-pin connectors that are very different in style. The left one is the RHD harness, the right one is the LHD harness.



The third images shows a pair of connectors from each harness that branch off together, no two connectors are the same. Left two are RHD, right two are LHD.



The next goes to the A/C compressor. Left (broken) is LHD and right is RHD. TDI A/C compressor only fits the right connector, not sure about the 1.8T one in my car. (EDIT: Yeah, I realized how dumb I was on this one. It's clearly just the broken part of the male connector in it)



The fifth and final different set is found off the main trunk right above the bell housing. The RHD harness has the two connectors on the left, while the LHD harness only has the single connector on the right.



From what I checked, all the wires going into these connectors are the same colours despite the connectors being different,with the exception of the plug that's missing entirely. My plan is to de-pin the connectors and just swap the housings as required. Are these differences in the harness purely from the year? Is this a bad plan and the harnesses are actually incompatible? Frans hasn't told me anything about it other than that it is for LHD cars.

After all that, I installed my Darkside Developments 51mm race pipe/EGR block off plate. It's a nice piece of kit, has good instructions, but requires a little modification to the charge-air hose to work (easy to do, but irreversible). It's great, I'll try to get a picture of it later.

mogly said:

I wish i'd seen this post earlier. WHen I converted my AVF-01E wagon years ago I opted to convert the TB tensioner to the BHW style stud unit for exactly the reasons you've noted. Good thing is that you can easily do it at next TB exchange.

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What is all involved in the conversion? Because I'm very interested in updating it next time!

I found this thread on vwaudiforum about an ASZ that a guy wanted to convert, but it didn't work for him. Then another guy chimmed in and said after swapping the back plate he had to drill and tap a new hole into the block (I think for the idler?) but he'd chewed up 2 belts in only a few months.

Koehn, now that i´m deep into it, i realize that it will actually be harder that i expected. From year to year, LHD/RHD, EU/US market there´s quite a few differences, so what´s valid for one person project, might not be for yours...

But by saying that, were i live, there´s all kind of jeep´s, VW, patrols, Samurais converted to PD engines, so if they can do it, it can be done with the right info and skill.

About the electrc fan, you will need more than the fan, it has some kind of control unit in the support, some pics:

https://1drv.ms/u/s!AlY1eE2P7cvOph7FzO3Ya4_CKJy3
https://1drv.ms/u/s!AlY1eE2P7cvOphwrHoq6qCmsOLCE
https://1drv.ms/u/s!AlY1eE2P7cvOph262aj9bmU327yJ

This a EU B6 AVF 2004MY, the fan is single for AC e radiator, and it´s variable speed, etc etc

Progress Report:

After weighing my options, I decided to try my hand at relocating the A/C compressor with the BPW bracket, converting the crank and alternator pulleys to 6-groove, and ditching the viscous fan for the electric setup already in my car. The accessory bracket I purchased has the part number 03G903143D. From what I can tell, 03G903139D is also identical. 7zap even shows a B6 AVF configured with this bracket, so I guess some cars came that way from the factory. The bracket still hasn't arrived so I can't actually verify that will even work for me yet. I found a used ALH crank pulley, and bought a new alternator pulley and replaced the 4-groove ones with those.The alternator pulley part number is 535 0012 100.

Last weekend I pulled the engine and transaxle out by following this guide for a V8. There's obviously a few key differences, but in general I found it very helpful! I thought I could keep the A/C and power steering lines connected, but I don't think that was possible. A/C system didn't have any Freon left in it anyways.



Pretty proud of being able to do it all solo! At the time, I didn't have the 17mm Allen driver so I decided to leave the front axles mounted. Because all the bolts on the exhaust downpipe were rusted and rounded, I couldn't remove the pipe either. The axles and the exhaust want to be in the exact same place. Make your life easier, remove those axles!



With the AMB 1.8T out I was able to better compare what I have. I learned the gas and diesel have different locations in the rain tray for the brake booster vacuum line. So I extended the connection behind the rain tray with some hose and moved the bulkhead grommet. (no pictures at the moment). I also discovered that while the A/C compressors are likely the same type, they have different pulley styles. The diesel one looks like it has a one-way clutch How important is that?

At this point, I've figured out where almost all of the engine harness connectors go to, which is nice! I've depinned and swapped a number of connectors between my two diesel harness and the gas engine harness. There's still two connectors mounted low and under the intake manifold area that I can't identify. If anyone knows what these are for it'd be greatly helpful!



The connectors in question are #2 and #4 shown in the image above. Here's closeups of the two showing that #2 has brown/green and red/white, and #4 has red/white and brown/yellow.




I compared the intercoolers between the 1.8T and the TDI and found a few key differences. First off, the 1.8T intercooler has a sensor on the upper end tank while the TDI doesn't. They have different dimensions and the TDI intercooler mounts to the frame with a different bracket than the 1.8T. The B6 TDI bracket apparently has the same part number as a B7 2.0T left side intercooler bracket (8E0 145 813G) which is nicely available in North America! I'm now considering getting the full B7 double-intercooler setup, but I don't yet know how that interacts with the existing B6 A/C drier which mounts in the front right.





Now some questions for people that know more than me!

As I mentioned above, what are those two connectors that I couldn't identify on the right side of the engine.

Also, when I did a quick comparison between the AWX and AMB harnesses of the Red, Black, Tan, and White connectors that go under the ECU box, I noticed a number of wires on the AWX that weren't on the AMB and thus were also not on the car side. I have the Bentley manual for the B6 which has comprehensive wiring diagrams for the gas, and I have the UK Haynes manual for the B6 petrol/diesel. It does not have comprehensive wiring diagrams and I suck at reading them anyways. Does anybody have information on what I need to do with these Red, Black, Tan, and White connectors to get it all to work?

groundscraper said:

Koehn, now that i´m deep into it, i realize that it will actually be harder that i expected. From year to year, LHD/RHD, EU/US market there´s quite a few differences, so what´s valid for one person project, might not be for yours...

But by saying that, were i live, there´s all kind of jeep´s, VW, patrols, Samurais converted to PD engines, so if they can do it, it can be done with the right info and skill.

About the electrc fan, you will need more than the fan, it has some kind of control unit in the support, some pics:

This a EU B6 AVF 2004MY, the fan is single for AC e radiator, and it´s variable speed, etc etc

Click to expand...

Dude you're so right, there's countless year to year differences!

Because my B6 already has the electric fan w/ control unit, I'm hoping there's an easier way to just use the existing equipment. I'm really really hoping!

Koehn said:

Dude you're so right, there's countless year to year differences!
Because my B6 already has the electric fan w/ control unit, I'm hoping there's an easier way to just use the existing equipment. I'm really really hoping!

Click to expand...

I have quite alot more info now, at least for my swap, i know the wiring color in all the plugs you mentioned, on the "e"plenum to the inside... i did an excel table with AKE to AVF, but i think it would not be of much help to you... since it´s EU market, and the chassis is a C5 allroad, and it´s a AVF engine going in... pretty sure most things would not match.

I´m learning to read VW diagrams(as much as i can), so i could trace the terminals and colours to each unit and plug. I discovered, that in my case almost every pin in the white, brown, orange, red and black plug match colour wise and function from AKE to AVF.

Maybe is what you´ll need to do... map the plugs from engine to chassis.

groundscraper said:

I have quite alot more info now, at least for my swap, i know the wiring color in all the plugs you mentioned, on the "e"plenum to the inside... i did an excel table with AKE to AVF, but i think it would not be of much help to you... since it´s EU market, and the chassis is a C5 allroad, and it´s a AVF engine going in... pretty sure most things would not match.
I´m learning to read VW diagrams(as much as i can), so i could trace the terminals and colours to each unit and plug. I discovered, that in my case almost every pin in the white, brown, orange, red and black plug match colour wise and function from AKE to AVF.
Maybe is what you´ll need to do... map the plugs from engine to chassis.

Click to expand...

I really appreciate the offer! But I think you're right, our cars are just too different. I don't have an orange connector in there at all!

I just finished drawing out each connector with the coloured wires I observed. I haven't yet determined the function of any of them, this was purely for a visual comparison by colour and location. It looks like a decent number of the pins are the same (at least by colour), but there's a fair amount that are very different also

I mentioned earlier that I have the North American Bentley manual and the diagrams are very comprehensive. Like so comprehensive I haven't a clue how to read them! But that manual only helps for the gas engine/chassis side of the wiring. Even once I've figured out that I'll need data on the diesel harness to compare the two

This helped me alot:

https://www.youtube.com/watch?v=jKnTjuSmwaE&t=225s
https://www.youtube.com/watch?v=bMn0i-yHhSA&t=6s

Thanks for those links, I'll definitely give them a watch!

And to anyone following along, sorry for the lack of images in these last posts! They all show on my end, but clearly there's an issue with the hosting service I'll try to sort that out after work today. I promise it's not supposed to be a wall of text

EDIT: I think the images are all fixed now

Alright! So I've spent the last while teaching myself both how to read wiring diagrams (huge thanks to groundscaper for linking those videos) and German (more on that later), which would make my grandparents proud.

I mentioned earlier that I had the Bentley service manual for the B6, so that had all the wiring diagrams I could ever need for the car side. My car is model year 2005 which means it's right at the end of B6 production so there was at least 1 instance of B7 wire colour-crossover that I noticed(T17e/14). After watching those RossTech videos, the diagrams were much much much simpler to read, but I know I still don't 100% understand them.

The diesel side was a lot more complicated. Since North America clearly never got this engine in the A4, and my UK Haynes manual doesn't have detailed diagrams, I didn't have access to the right stuff. I gained access to a *totally 100% legal* copy of ElsaWin v4.0 and was able to find diagrams for a 2003 A4 with a 1.9 AWX. I think that's what my harness comes from, honestly have no idea. The one caveat with these diagrams that I alluded to earlier, everything is in german. With the aid of google translate, and a number of hours, I managed to piece together the diesel side of my spreadsheet.

I've never really used Excel/Sheets before, but I managed to cobble together a document to help try to keep me organized. I also found pinout data online for the AMB from a few forums, so I added that information. It mostly just got me started.

Because I was learning as I went, there's a frustratingly-high level of inconsistency in my recorded data. The diesel side is much more thorough, but I think I should have everything I need.

If anyone wants to view/copy my information, you can find it here

Now I've gotta figure out how to rectify where the harnesses differ!

Lately I've felt progress has been hard to come by. I keep removing things from my car but nothing has gone back on it! Aaaaanyways

I removed the rear subframe with the intentions of gaining access to the fuel tank. In the process I discovered a proper mess of surface rust and a some fairly worn out bushings (260000+ kilometres will do that!). I was planning on replacing my rear control arm bushings, rear shocks, front struts, and front control arms at a later date. Since I was already in there, why not do it now.



After removing and the arms (only one bolt required cutting) and disconnecting the axles and pulling the rear diff, I attacked the subframe with a wire wheel. Managed to clean off a vast majority of the scaling there, and cleaned up the rear sway bar, upper control arm, and crossover pipe. After a fresh coat of Tremclad, it all looked serviceable once more.



Once my new parts arrived, I started work on removing the lower control arm bushings. Maybe it's just me, but these things are a total pain. After a few hours working the press, cutoff wheel, hammer and punch... I cracked an arm.



Clearly loading it in the press like this was a bad idea, but it worked for the previous arm and I honestly couldn't figure out any better way. Now I can either find another old arm and hope I don't break it pressing the old bushings out, or buy a new one $$$



Also, the plastic rings on the rear sway bar fell to pieces the moment I removed the bushings, anyone know if they're important/if you can buy replacements? I assume they're only supplied on the bar

Side note: I only recently discovered FCPEuro, and their prices on pretty much anything are hard to beat. Even with the terrible USD-CAD exchange rate and me having to pick up my parts from across the border

I have found the best way to remove most control arm bushing is with a ball joint press. It looks like a heavy duty c clamp. If you get lucky you press the bushing our in one shot otherwise the rubber and centre sleeve will press out then you just use a die grinder and very carefully grind a slit lengthwise in the outer sleeve and knock it out with a punch. That is how I replaced one of my rear upper control arm bushings on my A4 B7. What do you mean by plastic rings on the rear sway bar? The sway bar bushings? If so napa or carquest should be able to get them. I found Rock Auto is a pretty good place to get parts although I usually only use the website to look at pictures and prices then I buy local. I also found a good website for parts breakdowns on Audi’s https://parts.audiusa.com/a/Audi_20...LIZER-BAR--COMPONENTS-WO-QUATTRO/1397725.html.

Braddman said:

I have found the best way to remove most control arm bushing is with a ball joint press. It looks like a heavy duty c clamp. If you get lucky you press the bushing our in one shot otherwise the rubber and centre sleeve will press out then you just use a die grinder and very carefully grind a slit lengthwise in the outer sleeve and knock it out with a punch. That is how I replaced one of my rear upper control arm bushings on my A4 B7. What do you mean by plastic rings on the rear sway bar? The sway bar bushings? If so napa or carquest should be able to get them. I found Rock Auto is a pretty good place to get parts although I usually only use the website to look at pictures and prices then I buy local. I also found a good website for parts breakdowns on Audi’s https://parts.audiusa.com/a/Audi_20...LIZER-BAR--COMPONENTS-WO-QUATTRO/1397725.html.

Click to expand...

A ball joint press sounds like it would be very handy! Because most of the bushing seats have very small faces, it made it difficult to support the arm in the right places. But that's all finished for now.



These are the plastic rings I was talking about. They sit between the bushing and the bar. I believe they are mounted during the manufacturing process. I've got a used S4 sway bar coming from my local wrecker, so that'll be a nice upgrade at least.

I dropped the fuel tank today, what a beast! Everything went smoothly except for one fitting. The breather hose connection on top of the tank under the cargo compartment... I tried everything I could think of and I couldn't get it to unlock cleanly. I eventually got it apart, but not without damaging it. In hindsight, it seems like you have to pull the black collar in the same direction that you'll be removing the hose, but wasn't working for me. Seeing as the orange valve is welded to the tank, I may have to get creative to make sure that seals upon reinstallation. Anybody knowhow ot find the black plastic locking piece in the second photo (that's supposed to be one piece BTW)? I also found a barcode sticker on the tank with the label "KKB B7 Quattro LEV II" soooo is my fuel tank from a B7 now? Seems like it might be a replacement from a wrecker judging by the yellow marker on the tank.

QuickTD said:

Not sure why you removed the tank, everything is accessible via the panels beneath the rear seat. Late model B6's had the B7 tank. The major difference is that the suction jet pump plumbing is internal on the b7 tank where it was previously external. If you got an A4 Quattro diesel pump assembly it should be plug and play. The suction jet pump hole size may need to be drilled out to around .050" to provide enough flow to siphon the fuel across. The gas setup has a tiny hole but got the job done by running at 60psi. The diesel transfer pump is only 15psi.

The vent lines all connect to the filler neck. I just remove the charcoal canister connection and attach a filter to the vent. The filter used on the leak test pump is suitable. You'll find the leak test pump under the left rear fender liner. It, the charcoal canister and their associated plumbing can be removed.

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Removed the tank primarily so it's easier to remove the flapper and clean up anything that falls down the tube. How do you usually open it up?

Good tip on the charcoal canister delete by using the test pump filter. Do you just leave that sealed up in the compartment under the spare tire then?

I've got a used diesel FWD diesel pump assembly, I was planning on just swapping the pump over into the gasoline quattro holder. Or is even the pump itself different FWD->Quattro? Haven't yet had a chance to compare what I've got, should be opening the tank after work today.

QuickTD said:

I use the canister space inside the tire well to hide my contraband...

Click to expand...

I can't say I didn't think about that the second I cracked open that panel!


Now that I've got the lift pump out, I can see the one I received from Frans is quite different. It's on a rigid frame, that mounts straight up and down from the top flange, and has a narrower top plate.

The one in my tank seems to be very similar to the B7 ones I see on Google (makes sense), but with a white top plate. The base and top plate slide together on a rail with a spring, and the whole assembly sits angled in the fuel tank in relation to the access port.

The diesel pump was pretty easy to remove from it's carrier, but I don't think I can get the gas one out without breaking another part. I manage to poke the filter sock off the end, but it seems to be stuck to this larger white piece of plastic that won't fit through the opening...
EDIT: I just needed dinner. Second attempt, that little piece fell right off and the pump came off



The piece that has temporarily stopped progress



The B6 diesel lift pump assembly. It's apparently for a FWD car, but it seemed to have the connector relevant to the transfer siphon



My gasoline fuel pump, I definitely seem to have a mixed bag B6/B7 car!



The diesel pump assembly is both to tall and narrow to be used, so either I need to remove the gasoline pump from the carrier without breaking stuff (preferable), or I need to find a B7 diesel lift pump

For my A4 B7 BHW TDI swap I’m just using the gasoline fuel pump connected to a Holley carb fuel pressure regulator then about 9psi goes to the bhw fuel filter then tandem pump then the evap hardline under the car was used as a return line to the fuel tank. As the B7 2.0t didn’t have a return line. Also the fuel filter under the car was removed. I bought the car with the swap mostly finished and I am working on finishing it up. I have put 15,000km on the swap and the fuel setup seams to work great.