The Official B6 2.7T DIY/Swap Guide

[ketchup6624]

Are you still doing the wiring harness need one

[imallstressed]

I am using the 3.0 AC compressor from a B6. I think I used the wrong bracket, but I dont remember which one it was!!!! My AC compressor is not sticking out enough and it is chewing up the belt. Which bracket should I have used?

[AudiA4_20T]

Are you still doing the wiring harness need one

yes

[QuattroB5love]

Hey man, hope you're still checking this thread, I just did a 2.7T swap from an 01' A6 into a 98 A4 2.8, and I need some help with the wiring part, I just realized that my plugs don't match up at all and I was hoping you could either give me some help with how to splice in new connectors to plug in behind the Ecu or even better would be if you could maybe make an adapter or something, this is the last part of my swap and I'm like down in the dumps trying to figure it out on my own, any help at all would be much appreciated!

[AudiA4_20T]

Hey man, hope you're still checking this thread, I just did a 2.7T swap from an 01' A6 into a 98 A4 2.8, and I need some help with the wiring part, I just realized that my plugs don't match up at all and I was hoping you could either give me some help with how to splice in new connectors to plug in behind the Ecu or even better would be if you could maybe make an adapter or something, this is the last part of my swap and I'm like down in the dumps trying to figure it out on my own, any help at all would be much appreciated!

If I get the B5 diagrams I may be able to do something, but you're going to have to swap to DBW at the very minimum, I would have never used an early 98 for this swap.

[QuattroB5love]

I'm going to end up doing a facelift conversion with an S4 body harness and pedal and the entire center console, it will be a pain in the ass but at least it'll be right


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[Rlbarlow2]

Hello everyone. So I got the 2.7t mounted in to my 2004 A4 and got into the wiring with the auto tiptronic trans. Everything seemed to be too good to be true, until it was time to hook power up and see what happened on the Vag-Com. That's when the thunder and lightning struck. Not good news for me. Being that the TCM is mounted right under the ECM in the cowl on the B6, the communication wires go from one, right into the other. On an Allroad, the TCM is mounted under the seat and the communication wires go from there to the speedo and then to the ECM. The shop that is working on the wiring told me that being that the Allroad TCM is mounted farther away, the speed or wave length of the communication that is sent is different and will not communicate with the 2.7t ECM. I'm in no means a wiring expert but seemed to make sence, just not what I wanted to hear. I'm told the only way to cure this issue is to swap a manual transmission. Seeing if anyone has any ideas or am I stuck swapping the trans also? A 6 speed would obviously be preferred, just not quite in the cards right now. Any ideas would be greatfully helpful. Thank you.

[AudiA4_20T]

Hello everyone. So I got the 2.7t mounted in to my 2004 A4 and got into the wiring with the auto tiptronic trans. Everything seemed to be too good to be true, until it was time to hook power up and see what happened on the Vag-Com. That's when the thunder and lightning struck. Not good news for me. Being that the TCM is mounted right under the ECM in the cowl on the B6, the communication wires go from one, right into the other. On an Allroad, the TCM is mounted under the seat and the communication wires go from there to the speedo and then to the ECM. The shop that is working on the wiring told me that being that the Allroad TCM is mounted farther away, the speed or wave length of the communication that is sent is different and will not communicate with the 2.7t ECM. I'm in no means a wiring expert but seemed to make sence, just not what I wanted to hear. I'm told the only way to cure this issue is to swap a manual transmission. Seeing if anyone has any ideas or am I stuck swapping the trans also? A 6 speed would obviously be preferred, just not quite in the cards right now. Any ideas would be greatfully helpful. Thank you.

Sounds like a load of BS to me, I just don't think they feel like figuring out the wiring.

[Rlbarlow2]

I thought it was weird also. They tell me that everything is fine until the plug the TCM in and all communication is lost. Unplug the TCM and everything comes back up.

[wrcpulsar]

Hi I'm from uk been watching this thread for long time ,is there any wiring info on put a 2003 BES 2.7t into a 2003 1.8T b6 or is the wiring same ason the other 2.7T looms

Many thanks carl

[UkuRiSh]

many new swap, I'm miss my B7 so much :'(

[bondar1989]

Clint, PM sent for harness. thanks

[ADCS]

Hi I'm from uk been watching this thread for long time ,is there any wiring info on put a 2003 BES 2.7t into a 2003 1.8T b6 or is the wiring same ason the other 2.7T looms

Many thanks carl

The APB and BEL 2.7t have different harnesses, pinouts and ECU's so the BES is probably different as well. You need the diagrams for the specific model and year of the donor car and the car receiving the transplant.

[wrcpulsar]

Thanks guys , I've got plug pin outs for 2003 a4 1.8t , but after much searching can't find any plug pin outs for 2003 BES 2.7t allroad engine been told BEL might be the same but can't find that either ,anyone help please

[ADCS]

The Bentley has all the wire diagrams and pinouts. Same with alldatadiy.com (it's cheap. Subscribe for 1 year and then you can PDF anything). Any diagrams for a US '03-05 allroad or A6 with a 2.7t will be BEL. I don't know about the BES.

[AudiA4_20T]

Never seen a BES but figure it's probably similar to an '03 A6.

[wrcpulsar]

Thanks guys , I have an arp loom but alot different on the 2003 engine to the arp
OK I will keep searching for BEL wiring diagrams most likely to be the closest

[b5Fear2.8]

Hey Superhero...If you need a stage 1, or 2 Flash for the Bosch MAF ( Pre 2001 ) and either auto, or manual 6 spd. trans, I have several that you are welcome to, NO CHARGE. You'll need Nemoto Flash Tool , any version will do and an "Ebay" OBD2 cable ( 1281??), or the Vag-com cable.
Just let me know if you would like to try one. I am currently running one in my '00 A6 2.7T, M/T 6 spd. *** The tunes were written by someone whom now owns a major tuning company and are NOT for sale. I have given out a few, but I ask you to promise, give your word, to never sell a tune that I give out. of course, you can always change the tune to use with an Hitachi MAF, just a line of code in the MFLO address of the ME7.1 change from ""0"" to "200".

[Poopcorn]

Could any one tell me what's the easiest way to wire the cooling fan?
I'm looking at the hayden 3647 unit right now.
Thxxxx

[a2goblueguy]

Wow, the clif notes version of your build/swap... Needs to be added to the Wiki...

Where is this wiki you speak of? I am in the middle of this process and could use some more detailed instruction if available. Many thanks in advance.

[a2goblueguy]

The B6 Chassis has always been lost. It has looked high and low for years for the proper motor,
but always felt like there was something missing. That gap has been filled with the B6 2.7T
motor swap, and this is EVERYTHING you need to know.



What is the 2.7T?

It's basically the V6 version of a 1.8T, with not 1 K03, but two (AWESOME).

What years was it made? In North America, it was made from 2000-2004 and here are the differences

2000: Bosch MAF, bolt down coils, no immob
2001: Hitachi MAF, bolt down coils, no immob
2002: Hitachi MAF, bolt down coils, no immob
2003 (A6): Hitachi MAF, push down coils, immob, SAI (which sucks)
2004 (A6): Hitachi MAF, push down coils, immob, SAI (which sucks)

So which one should I get?

Honestly, this is preference. The 03-04 do have the push down coils and better ECUs, but this involves getting the immob defeated and also the tuning support sucks, so you are better off getting a 2000-2002 A6/S4 harness&ECU and going from there. The A6 and S4 are identical in parts so no difference between which one you get. Also, you can run any 00-02 ECU with any 00-02 harness. I would recommend getting a manual harness but it's not the biggest deal if you can't.

Is it easier to get the whole car or just the motor?

- Honestly you need nothing else from the car so I would look for a COMPLETE motor. You'll end up paying a LOT of money if you don't get something that's complete.

How much should I pay for the motor?

- This has a million factors at play, but a normal 2.7T goes for between $1200-2000. I paid $1200 but then had to get an ECU/fan module/etc.

What do I sacrifice with a swap like this?

- Absolutely nothing if you don't want to. All my gauges work, no CELs (due to the swap), and it drives like it was meant to be there. Cruise control is optional, and I haven't done it, but it can be done.

What do I need from said A6/S4 for all platforms? (parts by platform will be split up later)

- Entire Motor (EVERYTHING).
- Harness/ECU from the 2.7T
- A6/S4 power steering line
- A6/S4 SMIC brackets (if you don't want to run a FMIC)
- Snub mount bracket (one that attaches to the motor)
- Fan Control Module/Harness (unless you want to go some custom route)
- Alternator/Starter wire from the battery down the passenger frame rail
- Some kind of downpipes that fit. I've heard SSAC do, stock downpipes DO NOT

Which car should I start with?

This is also a tough question because it's preference. The easiest one BY FAR is the 3.0 because of the engine mounting, fuel system, A/C, radiator. The 3.0 block is basically just an aluminum 2.7T so it makes things easy. Some may prefer the 1.8T because you can get them cheap nowadays and some may prefer the S4 for the seats/brakes/bumpers/obviousthings/etc

Will I pass emissions?

While emissions varies state to state and technically putting an older motor in a newer car is not allowed, the car itself by this time thinks it has a 2.7T. VAG-COM reads 2.7T on it, you can clear codes, check them, log, check emissions, etc. So, when they hook the scanner up, as long as you have everything hooked up on the 2.7T to pass emissions, it will. This is awesome news because I know it can be a huge pain in some states

Now onto the swap....

-------------------------------------------------------------------------------

How does the motor mount up to the engine mounts?

1.8T: Drops right onto the mounting brackets
3.0: Drops right onto the mounting brackets
4.2: requires 1.8T/3.0 mounting brackets

How does the motor mount up to the trans?

1.8T: Needs B5 S4 trans plate (not verified)
3.0: Needs B5 S4 trans plate (this is a 2.7T trans)
4.2: Needs B5 S4 trans plate

What transmissions can I use?

- B5 A4 1.8T Quattro/FWD
- B5 A4 2.8 Quattro/FWD
- B5/A6 2.7T (preferred but needs other parts to install)
- B6 A4 1.8T Quattro/FWD
- B6 A4 3.0 (preferred)
- B6 S4 4.2 (preferred)

What clutch do I use?

- B5 S4 clutch/FW

How does the power steering hook up?

- Use an S4/A6 power steering line

Vehicle Speed Sensor (for speedo)

- This has come up before and people seem a bit confused about it. Basically, Audi made the early B6s (2002s) with a vehicle speed sensor in the trans, just like the B5. So, if you have a 2002, just plug it in! For 2003+, the speedo comes from the wheel speed sensor. This is great because nothing has to be done to have a speedo.

5k Rev Limiter Fix - The reason this is needed is because the B5 ECU needs to see speed. If it does not, the ECU goes into "Safe Mode" essentially. You have a few options here:

2002 Cars: You use your normal speed sensor and loop T10 (brown) pin 3 (white/blue) to T10m (black) pin 10 (brown/red)

2003+ Cars equipped with 01A/01E: You can either

A. Plug in a speed sensor into the port on your trans and loop T10 (brown) pin 3 (white/blue) to T10m (black) pin 10 (brown/red)
B. Route the white/blue wire shown on page 14 from the footwell to T10 (brown) pin 3 (white/blue). This will solve it as well and you won't need to use the speed sensor on the trans if you do it this way.

2003+ Cars with 0A3 (S4 trans): You do not have a speed sensor on the trans so you need to route the white/blue wire shown on page 14 from the footwell to T10 (brown) pin 3 (white/blue).

Reverse Lights:

1.8T: Plug connector in, also need to connect wiring on the jumper harness
3.0: Plug connector in, also need to connect wiring on the jumper harness
4.2: Need to wire connector in, also need to connect wiring on the jumper harness

Intake

- Has to be custom but honestly not too hard to do. Some people (like myself) just throw a cone filter on and call it a day. Some silicone and a few aluminum pipes could make you something nice.

Exhaust

- The cheapest way to get it running would be SSAC downpipes, mated to a stock S4 catback (which has decent sized piping for stock and can be found from Free.3-$200). Keep in mind this will require some custom welding, but shouldn't cost much.

**SSAC are not verified. You could also use B5/C5 trans mounts with the proper subframe. That WILL fit**

A/C

1.8T: Need Compressor - Reciever/Dryer hose
3.0: Plug n' Play
4.2: Need everything - Compressor, Both lines to compressor, Receiver/Dryer, line from Car-Receiver/Dryer.

*NOTE* Compressor Mount (06C 260 835 B) is not needed as previously stated. It's the same as the 2.7T bracket

Snub Mount

1.8T: 3.0 Snub Bracket
3.0: Bolts right up like factory
4.2: Need to get something welded

Fueling

1.8T: Need to get 3.0 return line or rig one up. Use 3.0 filter
3.0: Bolts right up like factory
4.2: Need to get 3.0 return line or rig one up. Use 3.0 filter

Radiator

1.8T: Need a 3.0/2.7T radiator
3.0: Bolts right up (need to cap off small port)
4.2: Need 3.0/2.7T radiator/grind some of the core support

SMICs

- Need 2.7T brackets with some drilling/tapping. Could also run Ebay FMIC

Heater Core

- 2.7T hoses fit perfect

Fans

- Ok so this is another thing that can really go a bunch of ways. The 2.7T ECU knows nothing of the fans in the S4/A6, because the 2.7T fan circuit is literally a different harness and module altogether. The B6 chassis use the ECU to control the fans so this becomes a problem.

So, you could:

1. Get the B5 S4 fan module and wire that in
2. Get a universal fan switch and hook that up to the B6 module to trigger the fans. There is a Hayden unit (3647 Adjustable Thermostatic Fan Control) for $35
3. Use the stock fan module on your car and wire it up like a relay using the sensor on the lower fan switch as the trigger. It's already pre-wired for the 2.7T. This is a bit easier on the 4.2 since it has a different module for each fan but it can be done on the 1.8T/3.0

Also, when you're deleting the mechanical fan, you can get these two pieces (078109123BA + N90216904) to cover up the area where the fan was. JHM sells a piece as well.

Wiring

- So everyone is freaking out about this wiring and it's not easy. Will I help you? Sure. Will I hold your hand and tell you where each wire goes? No. Maybe if this was 6 years ago and I had all the free time in the world, but I just plain don't have time anymore. I will be making plug and play harnesses based on chassis year, engine that came in that chassis, and year of the 2.7T. PM me for more information if you want to go that route.

-------------------------------------------------------------------------------

Please let me know if I've forgotten anything or if you have extra questions and I will add them to the DIY thread

Thanks,
Clint

Clint,

This is awesome. I am in the middle of this project and was wondering if there is are any resources with more detailed step-by-step instructions? I am inexperienced with this swap but very experienced with auto work in general.

Many Thanks in advance

Bill

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[AudiA4_20T]

Clint,

This is awesome. I am in the middle of this project and was wondering if there is are any resources with more detailed step-by-step instructions? I am inexperienced with this swap but very experienced with auto work in general.

Many Thanks in advance

Bill

Pretend you're pulling the 1.8T out and putting another one in. No difference. I've outlined the things you need to know.

[P1Racer]

I see you're in california, does your car pass smog? Have you gotten it smogged with the new smog devices yet?

[AudiA4_20T]

I see you're in california, does your car pass smog? Have you gotten it smogged with the new smog devices yet?

Didn't do the swap when I was living here, but yes technically the engine's ECU would report as if it was in an S4/A6, so as long as it would pass in the S4 it'll pass here.

[CxGrey]

Ok maybe I missed is somewhere along the way but I'm in the process of doing this swap on my b7. I've read just about everyone through this thread and many others but still feel like I'm missing it somewhere. I'm trying to figure out if I can use the fans that came in the b7 for cooling. It's obviously two electric fans. Does the b5 fan control module control the coolant fan as well as the ac fan? I'd like to use my old fans if possible. Maybe wire in the control module? If not what is needed to make the fans work like oem? Secondly is there anything different that needs to be done for the ac to work? Thanks in advance and sorry if I missed something.


Also when it comes to fueling going from a 2.0t to the 2.7t is there anything major that needs to be changed?

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[AudiA4_20T]

Ok maybe I missed is somewhere along the way but I'm in the process of doing this swap on my b7. I've read just about everyone through this thread and many others but still feel like I'm missing it somewhere. I'm trying to figure out if I can use the fans that came in the b7 for cooling. It's obviously two electric fans. Does the b5 fan control module control the coolant fan as well as the ac fan? I'd like to use my old fans if possible. Maybe wire in the control module? If not what is needed to make the fans work like oem? Secondly is there anything different that needs to be done for the ac to work? Thanks in advance and sorry if I missed something.


Also when it comes to fueling going from a 2.0t to the 2.7t is there anything major that needs to be changed?

Sent from my iPhone using Tapatalk

You could do it that way or you can use your factory module. You just need to run a wire down to the B6 A/C Compressor for the A/C.

[CxGrey]

You could do it that way or you can use your factory module. You just need to run a wire down to the B6 A/C Compressor for the A/C.

What exactly do you mean run a wire to it? What kind of wire do I run to it and from where to what on the compressor. It will have the 2.7t compressor on it, does this make a difference?

[Steve Bassen]

Has anyone run SRM intercoolers for their swap? Just wondering if the B5 stock mounting brackets are supposed to be used, or if they're better off with custom brackets being made.

[JB5]

Just wanted to drop this here:
Clint, thanks for the huge help with the harness and for answering my questions. I normally don't like to be hand held to figuring a problem out since I like the challenges, but this time I really needed to understand how some of the wiring worked, I thank you for that. YOU ARE THE MAN!!!!
AZ should feature you at the home page, since you motivated so many to do this swap, just throwing it out there.

went from this:


to this:

[S4iowa]

Has anyone run SRM intercoolers for their swap? Just wondering if the B5 stock mounting brackets are supposed to be used, or if they're better off with custom brackets being made.

I'm using them on my Tial 605 swap. I just used the upper outside mount tab and supported it with the outside headlight/fender mount. They really almost support them selves when hoses are all clamped down. THere's no room for them to move.

- - - Updated - - -

Just wanted to drop this here:
Clint, thanks for the huge help with the harness and for answering my questions. I normally don't like to be hand held to figuring a problem out since I like the challenges, but this time I really needed to understand how some of the wiring worked, I thank you for that. YOU ARE THE MAN!!!!
AZ should feature you at the home page, since you motivated so many to do this swap, just throwing it out there.


to this:

Nice job, looks pretty clean.

[JB5]

Thanks,

was hoping to get the Y pipe painted silver so it can look real clean, but the guy I gave it to paint, ran off with it and disappeared. had to buy another Y pipe from a local that thankfully had it.

[AudiA4_20T]

Cool, great job!

[mauromj]

I want to play!

[CxGrey]

I want to play!

That looks awesome and should be tons of fun.


On another note does anyone by any chance know the measurements of the two longer bolts needed for the starter with the trans spacer? Thread and length?

[elewsader]

I want to play!

It would appear that you play this game very well...

[mauromj]

It would appear that you play this game very well...

[LINDW4LL]

On another note does anyone by any chance know the measurements of the two longer bolts needed for the starter with the trans spacer? Thread and length?

I believe they're M12 x 110mm Not sure of pitch...

https://www.ecstuning.com/b-genuine-...ach/n90495704/


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[CxGrey]

I believe they're M12 x 110mm Not sure of pitch...

https://www.ecstuning.com/b-genuine-...ach/n90495704/


Sent from my iPhone 6 using Tapatalk

Those should be long enough to work with the spacer?

[JB5]

I want to play!

I was only looking for a little moment of shine, looks like I'm back in the dark now... thanks a lot
on a positive note... at least mine drives

But for real... that looks like is going to be a killer build, clean engine and setup keep it up man

I just wanted to get mine running and I think it took too long in my opinion (~4 months). while doing the swap I found I barely have any time to do anything. when i thought i was going to have time to work on it, i was sent to Brazil for work, Now I'm in Denver.

[AudiA4_20T]

I want to play!

yes