D3 A8 TDI Swap - First Start!

MKIV_TDI

Well-known member
Joined
Apr 8, 2012
Location
CT
TDI
2002 Jetta TDI, 2002 Golf TDI, '89 Audi 200 Wagon Quattro 2.5 AEL TDI
Hi there...

Well winter isn't all that far away so I'm preparing another TDI swap (my last one was an AllRoad 6SPD ALH... sold it on this forum)...

So I just picked up an '04 A8L with 109K miles with a blown engine (timing belt interval on the 4.2 is around 75k... so the p/o exceeded that greatly)...

I've got a freshly rebuilt BEW that I'm thinking of swapping into the A8. Has this been done before? Any advice as far as engine / tranny combo? Ideally I'd make this a 6SPD swap as well...

I'm still in the information gathering phase, but I'm starting to pull the 4.2 out this weekend... Open to tips/ideas/suggestions/etc.

Thanks!
 

Steve Addy

Top Post Dawg
Joined
Aug 7, 2002
Location
Iowa
TDI
97 Mk3
That's an awfully big car for a BEW. It would be a lot even for the SWB car but I wouldn't recommend it in the LWB car, it weighs in excess of 4200 lbs.

You could probably get by with the 3.0L TDI, even in the LWB but I wouldn't want to own a car that heavy and have it powered by a 4 cyl tdi.

Good luck

Steve
 

vwztips

Veteran Member
Joined
Aug 30, 2009
Location
Greenville, SC
TDI
2005 Passat GLS Wagon TDI 5 spd manual w/BSM delete 2012 Tiguan TDI/DSG 2005 Audi A4 6MQ 2011 BMW X5 35d
I did a AllRoad swap too but with a BHW engine. The AR weighed over 4000# too. I think the A8 is pushing 4400 #

Frankly if all the 4.2 has is bent valves, that is not a hard repair. I would consider just rebuilding the heads.
 

Hasenwerk

Vendor , w/Business number
Joined
Nov 28, 2003
Location
Quesnel, BC
TDI
1982 Cabriolet (BEW|VNT17|Stage4), 1989 VW TriStar Syncro soon-to-be CR TDI (CBEA), 2001 Ford Ranger Edge 4x4 (ALH|VNT17|R520|Stage4)
The V6 A8 made 325ft.lbs so a Stage 4 BEW with a 1749VB or Stage 5 with 1756VK would certainly give you more torque than the smallest stock engine. I can't see a power related problem here.

I think the A8L tips the scales at 2100kg which is nothing for the TDI. My Ranger with a Stage 4 ALH is 1700kg unloaded and it moves along very adequately and turns in a respectable 8L per 100 when doing so. I've hauled more than one car on a tow dolly with my Ranger and that would be 3000kg territory moving down the highway with ease.

I think the A8 is a brilliant car - love to see you pull the trigger on this one!
 

MKIV_TDI

Well-known member
Joined
Apr 8, 2012
Location
CT
TDI
2002 Jetta TDI, 2002 Golf TDI, '89 Audi 200 Wagon Quattro 2.5 AEL TDI
Okay well the "easy" part is done -- A8 engine and tranny came out as one piece yesterday. Time to see what space looks like...
 

MKIV_TDI

Well-known member
Joined
Apr 8, 2012
Location
CT
TDI
2002 Jetta TDI, 2002 Golf TDI, '89 Audi 200 Wagon Quattro 2.5 AEL TDI
After two and a half year hiatus from posting, thought I'd come back with an update! Like most 'side projects', work gets done little by little when we've got some spare time, which these days is harder to find now with a new grand-daughter in the family and the current 'pandemic' environment.

First, to clarify on my intro post; the swap engine wasn't a BEW like I incorrectly posted, but a BHW out of an '04 Passat TDI. Stock they were making around 136HP... this one has approx. 170HP based on the Malone tune on stock turbo. I'll entertain turbo upgrades once the car is buttoned together, registered, and road worthy.... but for now we're still far from that.

In the meantime, the engine has been fitted and matched to the 0B2 gearbox with all of the necessary mounting and driveshaft adaptation... Using a mini cooper clutch cylinder under the clutch pedal.

Open to some advice and/or suggestions on how to deal with:

1) The radiator fans. On the A8 they're controlled by the ECU and are PWM (pulse-width modulation).
2) Air conditioning and getting the A8 aircon to communicate with the BHW ECU.
3) Dashboard Speed Signal
4) Temperature Gauge
5) Glow Plug light on the dash
6) Fitting the front axles
7) and a million other various codes that I'll keep working through.

But, finally, the reason we all do these conversions... hearing the first start!


 

vwztips

Veteran Member
Joined
Aug 30, 2009
Location
Greenville, SC
TDI
2005 Passat GLS Wagon TDI 5 spd manual w/BSM delete 2012 Tiguan TDI/DSG 2005 Audi A4 6MQ 2011 BMW X5 35d
Reach out to Jetta 97 (marin). He has helped me a lot getting odd codes cleared. He has switched up the RPM face to match the TDI and used one of the icons for the GP for my Tiguan conversion
 
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MKIV_TDI

Well-known member
Joined
Apr 8, 2012
Location
CT
TDI
2002 Jetta TDI, 2002 Golf TDI, '89 Audi 200 Wagon Quattro 2.5 AEL TDI
Hey VWZTIPS, thank you for the heads up -- I'll PM him and pick his brain. New England has been getting snow every other day for the past two or three weeks so I haven't really done much since starting her up!
 
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