B7 Audi A4 BHW swap

[Land_o]

Starting a thread on my 2007 b7 a4 BHW swap. I have never taken on a project like this and figured I should share my journey and things I learn.

This Audi a4 Avant is a 2007 b7 with the 3.2l v6 (BKH engine code) mated to a 6 speed manual (FUB GYY trans code). Bought the car in Washington and trailered it home. Engine had 200k and was having issues at low rpm. Interior is mint making a perfect car for the swap. Got super lucky finding this.
Donor car is a Passat wagon with a blown transmission.

I ripped the front bumper off getting it off the trailer so might replace it or if the b7.5 front bumper is compatible I might look into that.

Got excited and started to pull the motor before winter. Couple cold day in the garage and got the motor fully removed. I left the transmission in the car hoping to just bolt the BHW on without having to mess with any of the transmission components. There are 3 bolts at the bottom of the transmission I was stuck on for a while. I ended up loosening the transmission and engine mounts, lifting the engine so I could get to them.

This is where the car stands as of today. I am waiting for parts in the mail and its way too cold to get anything done out there.
I got a 240mm LUK dual mass flywheel and clutch for a b7 a4 2.0t gas and a wiring harness for a BPW from over seas. The wiring harness is from the 2.0tdi a4 its manual but its RHD. That might bite me in the ass later might need to find another one.
The one part I am still having trouble finding is the engine/transmission spacer. I have been told it needs to be 6mm. The Audi had an 11mm spacer on it, so my plan is to get the one I have machined down to 6mm if I can't find one.

Parts list
-240mm clutch
-BPW starter
-BPW wiring harness look for LHD and manual
-BPW ECU
-Engine/trans spacer 01X103551 (5.7mm)
-Pilot bearing 06B105313D

Resources
-BHW pinout https://forums.tdiclub.com/index.php?threads/bhw-pinout.504755/
-Part numbers 7zap.com

Any advice is much appreciated

 

[PickleRick]

I can't post the link, my phone is glitchy. Search BHW 6 speed and it's one of the first threads that appear, used in conjunction with the euro starter and 240mm dmf

 

[Land_o]

I can't post the link, my phone is glitchy. Search BHW 6 speed and it's one of the first threads that appear, used in conjunction with the euro starter and 240mm dmf

I searched up bhw 6 speed and didn't see anything. That would be some handy knowledge to have. I had just assumed the started off the 3.2l would work. Is the euro starter different from what's in the 2.0t gas a4?

 

[PickleRick]

https://www.google.com/url?sa=t&sou...sQFnoECBAQAQ&usg=AOvVaw0CBRVClgafgfausUXA_TSM

[/URL]

 

[PickleRick]

I don't know why I can't copy and paste links on this site anymore.

On Google search bar I type BHW 6 speed conversion euro starter and the 5.5 spacer is posted in someone's parts break down.

As for the starter, no one has posted a 2.0 starter as an viable option that ive seen.

All the guys who use the euro 240mm dmf from darkside that lasts forever have used the euro starter. The TDI starters rarely seem to fail, I'm assuming they are built better than the gasser starters because of the high compression

 

[Windex]

2.0 starter won't work. Been there wattage is not high enough. You need the EU only diesel starter if you go with the 240mm DMF and clutch.

 

[Land_o]

I found the post you are talking about

I don't know why I can't copy and paste links on this site anymore.

On Google search bar I type BHW 6 speed conversion euro starter and the 5.5 spacer is posted in someone's parts break down.

As for the starter, no one has posted a 2.0 starter as an viable option that ive seen.

All the guys who use the euro 240mm dmf from darkside that lasts forever have used the euro starter. The TDI starters rarely seem to fail, I'm assuming they are built better than the gasser starters because of the high compression

So I found the thread you are talking about. I believe they used a 01E transmission out of a b5? The b7 6 speed I believe is called a GVE. Definitely correct me if I'm wrong. Not sure if I will run into the same issue with a different transmission. They also ran into different length crank shafts due to the auto to manual swap. Looks like they solved the spacer problem with a 5.5mm spacer and a new crank. I would prefer to leave internals alone if I can help it.

 

[PickleRick]

You don't need a new crank, just install the pilot bearing and let it sit a little proud. He's the only poster I've seen use a different crank. The 6 speed conversions in the BHW B5.5 Passats are pretty well documented at this point but the threads are spread between the b5.5 section and here.


I don't know if your 6 speed has the same input shaft issues as the TDI 6 speeds.

If it doesn't, Matt whitbread has a 240 single mass flywheel that allows you to use it with no spacer and reuse the BHW factory starter. The south bend clutch he pairs with them now (the organic) is very smooth.

 

[Koehn]

I found the post you are talking about


So I found the thread you are talking about. I believe they used a 01E transmission out of a b5? The b7 6 speed I believe is called a GVE. Definitely correct me if I'm wrong. Not sure if I will run into the same issue with a different transmission. They also ran into different length crank shafts due to the auto to manual swap. Looks like they solved the spacer problem with a 5.5mm spacer and a new crank. I would prefer to leave internals alone if I can help it.

GVE is the specific transmission code, with that you can find out your gear ratios. The type of transmission would actually be 02X. I've been running my 02X (GJW) in my B6 with no spacer without any issues, but I suppose that depends a bit on your clutch. I'm running the European OE setup: so stock 240mm DMF, stock clutch and pressure plate with the EU-specific starter.

The starter is great, but the clutch isn't my favourite. It's definitely struggling to hold my upgraded turbo, and it also doesn't love stop and go traffic and can get quite shuddery. I've done a ton of research on clutch options and IMO the best option would be to use Matt Whitbread's 240mm flywheel (with stock BHW starter), and a modified B7 RS4 clutch and pressure plate. His flywheel is setup to take a OEM B5 RS4 clutch and pressure plate which is good, but the B7's is even better. The mods to make the B7 clutch work basically amount to shrinking the diameter of the dowel pins (or enlarging the PP's holes) and shimming it out 2mm. People on Audizine have done this with similar setups on their big turbo 1.8T's so I believe it to work quite well.

All that said, I'm not sure how well our 02X's handle the diesel with a SMF, so a Fluidampr may be required.

 

[Land_o]

Little update here. Most of the parts have arrived and have the motor on a stand in the garage. Just ordered a ALH oil pump for the balance shaft delete and I should have the rest of the parts ready for that.
Used Euro TDI starter and BPW harness have arrived as well.

Clutch and DMF I got are
LuK Dual Mass Flywheel and Clutch Kit for Audi A4 / A6 B7 Platform off of darksidedevelopments.co.uk SKU is DSD1345
The kit is for b7 2.0 TDI from over seas
I reached out to darkside and it sounds like this setup is good for 340 lbft which should be a good start. They have an SRE version that can hold 400lbft on the same flywheel SKU for that one is DSD1257.1

I am hoping with Euro parts it wont even need a spacer but once I get the clutch on I can start taking measurements and find out.

 

[Land_o]

Another update here. Got the motor in after fuffing around with it for a couple days. I ended up screwing in 4 of the bolts that connect the motor to the transmission loosely to guide it into place. All while the transmission was propped up with a jack. I had to turn over the motor a little bit to get the input shaft to line up with the clutch. I did a balance shaft delete and new timing belt/waterpump while it was out.

A couple general notes that I learned.
-This combination of motor and transmission uses shorter hardware to mate the motor and transmission. The hardware off the audi was too long. And the alignment dowel were the same size so I didn't need to mess with them
-After measuring and remeasuring it looked like the input shaft would not go deep enough into the pilot bearing with a spacer so I did not use one.(You need a spacer or clutch with rub on trans housing)
-I installed the pilot bearing about 1mm proud just to make sure the input shaft got deep enough into it. I will attach my drawing with the measurements on it. (Used a different pilot bearing part number in first post)
-I should have taken to clutch slave cylinder out while fitting all of this. If the cylinder does not have back pressure on it from the clutch you can blow it up easily which I learned the hard way. So any tips on bleeding the clutch system would be welcome.
-I had to switch the chassis motor mounts to the ones from the Passat. The rubber motor mounts seemed to be the same on both vehicles so I ordered some new ones and a fuel pump for the Passat. The fuel pump looked about the same size so hoping it will just fit in the tank. (It did not fit I recommend leaving the gas pump alone and just suck out as much gas around it as you can, then use a fuel pressure regulator in the engine compartment)

Now to empty and fuel tank get the coolant system sorted and change the exhaust over.

The measurements on the diagram are approximations and I would not count on them being exact******

 

[PickleRick]

The Passat fuel pump (diesel specific) will run @ the same psi as an EFI pump. The little bucket assembly that the fuel pump mounts in also has a fuel regulator in it. So unless you also retrofit this REGULATOR or install a return TEE before the fuel filter under the hood you'll have too much fuel pressure

 

[Land_o]

So I got the whole fuel pump assembly with the bucket, float ect. Does that have a regulator in it? The listing for it said it runs at min 10psi and max 14psi. I can always add a regulator before the fuel filter. Is it worth me checking the line psi when I get it installed. The fuel pump is AUTOBEST F4683A off of rock auto.

 

[Windex]

Make sure the engine turns - there's a reason for the 5.5mm spacer.

 

[ImperfektMechaniker]

@Land_o im doing a similar conversion by the in a b5.5. Using th GJW O2x transmission. I have a build thread under the b5 section. We are practically in the same position lol. Linked here: https://forums.tdiclub.com/index.ph...ily-driver-4motion-tdi-b5-5-wagon-6mt.526092/

Have you decided how you are gonna go about with the fuel pressure? I heard bridging the return and feed works? Let me know your guys’ thoughts

 

[Land_o]

The motor turns over and spins the wheels while its in gear. I am worried about the clutch petal not going all the way to the floor. Once I get the clutch system back together we will see.

@ImperfektMechaniker haha I'm just reading through your thread here. You did quite a better job documenting. The exact same thing happed when I tried to pull off the BS crank cog. It broke into 5 pieces and I busted out the Dremel, mine looks identical. And I can confirm they really pack the v6 into these things. I will be following along. I'm sure we have slightly different transmissions but are you going to use a transmission/engine spacer? From the measurements on mine I don't think I can.

As far as fuel pressure I have the Passat tdi fuel pump assembly in the mail. The listing said it does 10-14 psi so I think I am set.

However my buddy did this on his swap for a cheap quick work around. No regulator just a TEE before the fuel filter using the stock(gas) fuel pump that was in the truck. He says it works just fine doing it this way.

 

[ImperfektMechaniker]

The motor turns over and spins the wheels while its in gear. I am worried about the clutch petal not going all the way to the floor. Once I get the clutch system back together we will see.

@ImperfektMechaniker haha I'm just reading through your thread here. You did quite a better job documenting. The exact same thing happed when I tried to pull off the BS crank cog. It broke into 5 pieces and I busted out the Dremel, mine looks identical. And I can confirm they really pack the v6 into these things. I will be following along. I'm sure we have slightly different transmissions but are you going to use a transmission/engine spacer? From the measurements on mine I don't think I can.

As far as fuel pressure I have the Passat tdi fuel pump assembly in the mail. The listing said it does 10-14 psi so I think I am set.

However my buddy did this on his swap for a cheap quick work around. No regulator just a TEE before the fuel filter using the stock(gas) fuel pump that was in the truck. He says it works just fine doing it this way.

i admit it’s a bit overkill, but I wanted something to look back on! I wish I did this with my mk2! Also the forum community is awesome!

The BHW fits so easily and well in these cars!

I am not using a trans spacer. I’m using a 228mm clutch setup with the usp motor sports SS braided line and clutch slave. I wonder why you’re experiencing such a firm clutch pedal. What slave are you using? I have yet to bleed mine I’m hoping I won’t run into the same issue.

 

[Land_o]

i admit it’s a bit overkill, but I wanted something to look back on! I wish I did this with my mk2! Also the forum community is awesome!

The BHW fits so easily and well in these cars!

I am not using a trans spacer. I’m using a 228mm clutch setup with the usp motor sports SS braided line and clutch slave. I wonder why you’re experiencing such a firm clutch pedal. What slave are you using? I have yet to bleed mine I’m hoping I won’t run into the same issue.

I guess what can happen with the slave cylinder is when you have the motor out there is no clutch to have pressure on the throwout bearing so no pressure on the slave. the piston on the slave overextends gets stuck so the clutch petal is stuck up. You kick the clutch petal and blow up the slave.
This might also be unique to pulling the motor and leaving the trans in the car. The slave might have been OEM not sure.

 

[ImperfektMechaniker]

I guess what can happen with the slave cylinder is when you have the motor out there is no clutch to have pressure on the throwout bearing so no pressure on the slave. the piston on the slave overextends gets stuck so the clutch petal is stuck up. You kick the clutch petal and blow up the slave.
This might also be unique to pulling the motor and leaving the trans in the car. The slave might have been OEM not sure.

Oh I see what your talking about. did you push down on the clutch pedal then? Ive never seen this happen maybe its this generation specific.

 

[Land_o]

Oh I see what your talking about. did you push down on the clutch pedal then? Ive never seen this happen maybe its this generation specific.

I did yeah and it exploded, guess they always tell you not to force things that are stuck. The work around is have someone sit in the car lightly jiggling the clutch petal while you press the piston on the slave in by hand. I recommend removing the slave while mating the engine and transmission. I wanted to mention it because I only saw it in one other place in an unrelated forum after I had already blown it up. Even called a local vw/Audi shop and the guy on the phone seemed to have no idea what I was talking about.

 

[PickleRick]

The same thing can happen to a brake caliper piston/drum brake cylinder if you press the brake pedal with it unattached.

You're not the first one to do it, won't be the last. I'm not going to mention how I know what happens.

 

[Land_o]

The same thing can happen to a brake caliper piston/drum brake cylinder if you press the brake pedal with it unattached.

You're not the first one to do it, won't be the last. I'm not going to mention how I know what happens.

Haha guess everyone learns eventually most probably learn the hard way. I'm sure this is common knowledge to any mechanic worth their salt. But us YouTube mechanics have plenty to learn.

 

[Land_o]

Another update
Got a BPW starter, ECU, and LHD wiring harness from Germany and are installed on the car.

http://imgur.com/yjiLfxY

Fuel pressure regulator is temporarily installed to use in conjunction with the stock fuel pump. Maybe someone could also tell me if that is indeed the fuel return going into the passenger side wheel well.

http://imgur.com/jLxnj4V

I don't think I have mentioned 7zap.com for general part diagrams. Its not 100% but is a great free*** resource for finding parts. (CTRL F is my best friend)

I will edit the first post with an updated parts list as I think I am getting close here.

I plugged the battery back in for the first time since the engine was out. Plugged in vagcom and the battery died so waiting for it to charge.
Up next is dealing with the immobilizer. Will most likely have to send off one of the ECUs for tuning and immobilizer fixing.

Got a couple questions I could use some insight on.
-Does it matter which ECU I use (BHW vs BPW) ive got both of them now. ie does the ecu have any body control? If either ecu will work, maybe just use BHW as it is the ecu that is paired with the motor.
-I wish I took a picture of these cables as they are burred now but the main power cable off of the alternator has 2 parts one being a single pin connector which I assumed was for starter control solenoid (it is) and the other being power, both I connected to the starter. Also connected the main large power cable off the the battery to the starter. Starter also has an additional ground that I connected. Did I connect all of those correctly? Nothing is going to blow up?
-Has anyone seen a good list for all the engine wiring harness connections? There are still a bunch of unknown connections left unplugged on the harness and the front clip is still off of the car. Just trying to get the necessities to turn it over. I have a diagram but half of them are listed as the same plug. Looking for a good list I can go down a check off one by one.
-With the immobilizer active I should still be able to turn over the motor and maybe even start for a couple seconds? At least I think I read that somewhere?

Thanks as always for the help

 

[arazvan2002]

For starting, you can use the BHW ECU, it should be ok, but plug it and check with VCDS. BPW engine have other injectors (same flow as ARL ones). After you will pair BPW Ecu with cluster, then you should mod your software to pair with the injectors. (you can PM on that matter).
For wiring and other bits, you need ELSAWin installed, to check the diagrams. Maybe also ETKA, for parts (from where 7zap is copied).
You should be able to start it for few seconds even with immo.

 

[Land_o]

For starting, you can use the BHW ECU, it should be ok, but plug it and check with VCDS. BPW engine have other injectors (same flow as ARL ones). After you will pair BPW Ecu with cluster, then you should mod your software to pair with the injectors. (you can PM on that matter).
For wiring and other bits, you need ELSAWin installed, to check the diagrams. Maybe also ETKA, for parts (from where 7zap is copied).
You should be able to start it for few seconds even with immo.

Much appreciated. So I got the battery charged and tested so good there, but still no crank with either ecu. VCDS is also not communicating with the ECU for some reason? It will scan other modules so something is working at least. The throttle body is making a clicking noise and the battery light on the dash is blinking with the clicks. The throttle body is wide open and if I close it with my finger it opens itself back up. Any ideas on getting VCDS to see the ECU?

Also what I thought was an extra ground on the starter just holds a plastic clip. The ground wire just bridges from above the motor mount to below it.

 

[mogly]

Take booster cables and temporarily add a ground. Won't hurt anything. Have you attempted to hit the exciter wire with 12V and see if the engine fires? Maybe it's an issue only in the start exciter circuit?

 

[Land_o]

Take booster cables and temporarily add a ground. Won't hurt anything. Have you attempted to hit the exciter wire with 12V and see if the engine fires? Maybe it's an issue only in the start exciter circuit?

So I've jumped the starter solenoid with a wire straight off the battery and the motor turns over! So it's got to be electrical somewhere. Bad ground or missing a connection somewhere. Any critical things to check?

 

[Land_o]

So this confusion about the starter solenoid "exciter" wire. The wire comes in a bundle from the alternator. Halfway down the bundle is a connector from the engine harness. It's a one pin that I had connected earlier so the trouble is elsewhere. Still working on why VCDS won't talk to the engine.

In VCDS just to confirm. Under the drivetrain tab 01-engine should be ECM/ECU? I also tried 11-engine II, 21-engine III/batt 2, and 31-engine other. No response from any of them but I assume 01-engine is the correct module I'm looking for.

 

[adamss24]

Yep, 1st tab is the engine ecu module which should scan the ecu for fault codes, if you cannot talk to it look at the fuses in the side of the dash- under the cover !

 

[Land_o]

Another update. I got the motor turning over. I was using a K-line vcds cable and needed one that had CAN. So now I can talk to the ECU with no issues. The no turn over was the clutch position wire not getting to the starter inhibitor relay. The fix was simple once I started testing wires and spent hours staring at wiring diagrams.

Now I am working on syncing the IMMO with the ECU and cluster while I get the rest of the car put back together. This seems to be a sticking point. I have a couple locksmiths who are getting back to me about paying them to do it. Id like to learn if anyone could point me in the right direction.

From what I have read the process is very simple if you can get your hands on the ECU security pin or SKC code. Looking for this code I have tried a couple different programs. Vag EEPROM Programmer v1.19, VAG k+can commander v3.6, and a custom tool called KW1281Test link for that here https://github.com/gmenounos/kw1281test/releases. My machine is windows 10 and I got the correct drivers from ross tech for virtual com ports. following this guide https://sites.google.com/site/imnuts/home/install-setup-ross-tech-vcp-drivers

Still no luck. Did some more reading and there is a chance the IMMO version is too new to work with these programs? IMMO 4c is the newest version that is supported? Anyone know where to find what IMMO version is on the ECU?
Control Module Part Number: 03G 906 016 KN HW: 03G 906 016 KN Component and/or Version: R4 2,0L EDC G000SG 9894

Most likely I will just have to send it off to get it done. I've spent a bit too much time trying to figure it out.