'01 Audi A4 1.8T quattro TDI Conversion

GoremanX

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2001 Audi A4 Avant quattro w/BHW TDI & 01E 6-speed
Currently I'm waiting on a part to resolve a pesky engine light on the Passat. Once that issue is resolved, I'll have it inspected to be roadworthy in the state of Vermont, in case I need to drive it anywhere in the near future. Once it passes inspection, I'll get started on pulling the engine out.

I'm also waiting on my tax refund to buy some of the parts I'll be needing. But of course the IRS has delayed tax season this year...
 

tophergrace

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Alh
Not even close, unfortunately. A manual trans A4 1.8T has an 01A transmission with a 4.11 final drive. I already acquired a 3.889 rear end from an automatic 2001 S4, which is a bolt-in replacement. Also has the bonus of 108mm flanges for rear axle shafts, which are more resilient for handling the torque of a modified BHW. A few companies sell upgraded S4 axles that are bolt-in and can take all the beating I'll throw at them.


That may be true for a Passat, but a 6-speed manual is a bolt-in for an A4. The S4 came from the factory with a 6-speed manual (01E), and the mounting points are all the same. Swapping in a 6-speed is fairly common in the B5 A4 community. The diesel 6-speed is also an 01E, it just has different gearing. The only thing I'll need is an S4 driveshaft to go to the rear end.

Your car should already have a 3.89 rear end in it:p Hope you didn't waste money on a rear end
 

GoremanX

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2001 Audi A4 Avant quattro w/BHW TDI & 01E 6-speed
Thanks, that was already covered on page 2.
 

Scott_DeWitt

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2000 Audi A4 1.9TDI quattro
For the 1.9 B5 I have at the shop, I used a 5 speed trans with a .659 ratio 5th gear and 3.70 final drives.
 

GoremanX

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2001 Audi A4 Avant quattro w/BHW TDI & 01E 6-speed
Now that's interesting... once I finally get my tax refund, we'll need to discuss what my best option is for this build.

...slow IRS...
 

CLETDI

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Jan 27, 2015
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Cleveland
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2013 Jetta TDI
Randomly came across your beauty avant doing a Google search for pelican blue audis. Amazing! I didn't read through this thread too closely, so I don't know if you explained how to do the swap. Was it easy? How much did you pay for the Audi if you don't mind me asking.
 

GoremanX

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2001 Audi A4 Avant quattro w/BHW TDI & 01E 6-speed
oh boy... don't get me started. The swap isn't done. I've got everything sitting there in my garage, ready to be swapped in, except for ONE vital part. I bought this vital part almost a year ago now, and the seller has been pulling me by the nose ever since. I get stories, repeated broken promises, new expected shipping dates... and nada. I've still got nothing to show for it except a huge hole in my finances where thousands of dollars used to be. I can't even begin to describe how disappointing this experience has been so far.

I paid $2995 for the car 3 years ago. It's been the most awesome car I've ever owned. It can only get more awesome once I get the TDI swap completed... IF it ever gets completed.
 

GoremanX

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2001 Audi A4 Avant quattro w/BHW TDI & 01E 6-speed
Technically it's not just *a* part but a bunch of them, and they're all necessary. I don't want to mention the parts or the seller yet. There's still a chance they'll come through and provide me with what I purchased. I'm optimistic that way, I always give people the benefit of the doubt, even after almost 11 months. It's one of my biggest flaws.

At this point though I'm starting to feel that sinking feeling like I was had and I've lost all my money.
 

GoremanX

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2001 Audi A4 Avant quattro w/BHW TDI & 01E 6-speed
First off, some good news: IT'S HERE! I finally got the parts I ordered a year ago! I must offer sincere apologies to the supplier (who shall continue to remain nameless) for ever doubting them. They worked hard to make this all work out for me, and I really appreciate it. I got kinda terse about the whole issue over the last few months. But I have to admit that my order was somewhat uncommon. Perhaps better communication on both sides would've avoided a lot of misunderstandings. In any case, the issue is resolved and now I'm a happy camper.

So... let the TDI conversion resume!
 

Ifixit

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Feb 13, 2011
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Waitsfield, VT
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97 B4 Passat GLX TDI Wagon & 99 Golf & 05 Passat 4motion Manual & 04 Audi A4 Avant
Awesome! cant wait to see some progress
I am starting a BHW swap into my 05 A4 B6 1.8 in about a month!
I have gathered all my parts already including an EDC15P ecu and harness, injectors 01E ect
Ive had the A4 since last year in storage and I was really wishing I was driving it this winter as my mountain pass drive to work is not that easy in a FWD Golf!
Great car for vermont for sure!
 

GoremanX

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2001 Audi A4 Avant quattro w/BHW TDI & 01E 6-speed
I'm finally getting stuff done, which is really satisfying. Got the front end off the donor Passat today. It's amazing, nothing was broken, missing or seized. I've NEVER had such an experience on a used car before. Almost a shame to be stealing its engine :D It's an absolute joy to work on.

If I didn't know better, I'd say the front carrier has NEVER been put in service position before. But this car has 220k miles on it, so that can't be possible. About the only thing that was missing is some bolts on the belly pan, and it's a miracle if those fasteners are ever intact.

The "stuff" that came out of the radiator is downright scary. It was thick, nasty brown goo followed by clear brownish water. No G12 or G13 in sight.

The "stuff" that came out of the transmission lines was even scarier. Black sludge. Not even sure how that stuff did its job.

Next step, removing the engine/transmission!
 
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GoremanX

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2001 Audi A4 Avant quattro w/BHW TDI & 01E 6-speed
Awesome! cant wait to see some progress
I am starting a BHW swap into my 05 A4 B6 1.8 in about a month!
I have gathered all my parts already including an EDC15P ecu and harness, injectors 01E ect
Ive had the A4 since last year in storage and I was really wishing I was driving it this winter as my mountain pass drive to work is not that easy in a FWD Golf!
Great car for vermont for sure!
Hey you're only an hour away from me! I'm in Georgia, just north of Milton. I've got a bunch of Audi- and TDI-specific tools that I got for this transplant. You're welcome to borrow them if you need them.
 

Ifixit

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Waitsfield, VT
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97 B4 Passat GLX TDI Wagon & 99 Golf & 05 Passat 4motion Manual & 04 Audi A4 Avant
Hey you're only an hour away from me! I'm in Georgia, just north of Milton. I've got a bunch of Audi- and TDI-specific tools that I got for this transplant. You're welcome to borrow them if you need them.
Hey Thanks! I work at a Vag/TDi Shop up here so we have loads of special tools but thanks!
I will definitely be watching as your swap progresses and I will start a thread when mine begins.
Have you decided what engine controller you are going to use yet?
EDC16 and bhw passat harness or EDC15P and euro harness?
I can tell you the Passat harness is definitely not plug and play but usable with some adjustment.
I got a euro harness and EDC15P just because of the ease of tuning and because the EDC16 will not fit in the audis engine controller box easily (plastic box under the cowl/winshield) and the passat box wont fit the audi
but I think the box from a A4 B7 would work with EDC16 and Fit my A4 B6 but not sure it would fit a A4 B5
The harness I got came from a right-hand drive so it's a little long also something to keep in mind if you end up purchasing a euro harness try to find left-hand drive
Funny about the transmission fluid
I see that pretty regularly..and during a rebuild.. stinks terribly
Makes you wonder what the life expectancy of a "lifetime" fluid is
I can definitely tell you that the life expectancy of a gearbox running fluid like that for an extended time:)
 
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GoremanX

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2001 Audi A4 Avant quattro w/BHW TDI & 01E 6-speed
Actually the ECU is one of the few things I have not yet settled on. It's very hard to find info on this online, and my searches mostly came up empty. I figured I'd tackle that once I know my block and head are sound. No point worrying about stuff that won't even come up if I get stalled in my tracks. But if I can just use the Passat wiring harness and make it work for my needs, that would save me a lot of money. And considering the extent to which I'm building this engine, I need to start saving money somewhere.

Woohoo! A photo of actual progress!



...and, snow :mad:
 

GoremanX

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2001 Audi A4 Avant quattro w/BHW TDI & 01E 6-speed
So in regards to the ECU and engine wiring harness, how feasible is this?

- buy a European ECU from a PD TDI A4 (engine codes AJM or ATJ, which is a 1.9 PD)

- pull the wires out of the ECU engine connector on my Passat engine harness

- re-connect the wires to my A4's ECU connector in the proper order to connect to the European ECU

- have a tuner provide me with a basic 1-bar tune for initial break-in period

Seems like that would retain all my A4's features (cruise control, etc) while interfacing with the engine without issues.

Thoughts?
 

Ifixit

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97 B4 Passat GLX TDI Wagon & 99 Golf & 05 Passat 4motion Manual & 04 Audi A4 Avant
That is basically the exact conclusion that I came to and why I chose that route
Not to say that you couldn't use the Passat harness and engine controller but the euro ECU and harness is going to be the best match with the least amount of work for you and your tuner
In fact as long as your BHW injectors are compatible with that ECU it Will work without any modifications to that file in the ECU
I would highly recommend purchasing the engine harness as well from a left hand drive euro A4 TDI because the connectors are also different between EDC 16 and EDC 15 P and will save you a lot of rewiring
EDC15p is the ECU that will you will get from a euro a4 TDI of that era
 

GoremanX

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2001 Audi A4 Avant quattro w/BHW TDI & 01E 6-speed
I've nearly got the engine out of the Passat. I only have to disconnect some connectors at the transmission and the shifter, and the whole thing should come right out. Just waiting on a load leveler to attach to my engine hoist. I hope to have that by Monday.
 

Ifixit

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97 B4 Passat GLX TDI Wagon & 99 Golf & 05 Passat 4motion Manual & 04 Audi A4 Avant
Nice!
I also forgot to mention if you go with a euro EC you you'll need an intake and EGR valve unless you're going to delete EGR and ASV anyway
Euro PD engines still used vacuum control for both those functions
 

GoremanX

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2001 Audi A4 Avant quattro w/BHW TDI & 01E 6-speed
Nice!
I also forgot to mention if you go with a euro EC you you'll need an intake and EGR valve unless you're going to delete EGR and ASV anyway
Euro PD engines still used vacuum control for both those functions
ugh... that's discouraging. I'm trying to get this done with a minimum of European parts, both for cost and convenience reasons. I'm also trying to keep the OEM intake manifold with EGR and flapper functionality.

I wonder how hard it would be to re-purpose the Passat ECU? I was under the mistaken impression that one of the ECU connectors was for the dash wiring harness, and the other connector was for the engine. But now that I have it all apart, I see that both ECU connectors are essentially part of the engine harness. The only wires going into the dash are 6 separate modular connectors that don't connect to the ECU itself (although I'm sure most of those wires come from there). So it seems to me that all I'd need to do is figure out the wiring of those 6 modular connectors and send the appropriate signals into the dash for everything to work. I'm sure it's not a 1:1 correlation, but maybe the differences can be kludged? Then I'd just need the immobilizer defeated in the ECU.

As for fitting the ECU, it looks like the box its in is the exact same shape and size on the Passat and A4. I could probably just swap them out, then the Passat ECU would fit just fine. I was planning on putting a 1.8T in the Passat and reselling it anyways.
 

GoremanX

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2001 Audi A4 Avant quattro w/BHW TDI & 01E 6-speed
More progress!

Yesterday I got the engine out of the Passat:





I totally forgot to unbolt the torque converter from the flex plate before separating the engine from the transmission:



But luckily the transmission was pretty much empty already anyways, no big mess. I removed the torque converter and flex plate, and got the engine mounted on a stand:







All the "stuff" is still on the engine; wiring harness, accessories, hoses, etc. About the only thing I took off to get the engine out are the flapper (to get to the right rear lift point on the head) and the AC compressor. I also removed the starter to get the transmission off. It's a lot easier to take a bunch of pictures now that it's out of the car, so I can tell exactly how it goes back together. This engine is WAY simpler than the 1.8T it's replacing.

Considering I only have about 2-3 hours a day to work on this, I'm very happy with the progress.

Next up, tear-down! Unfortunately, I'm coming down with a cold, so that will slow me down over the next few days.

Now I gotta figure out what to do with this transmission... it's not geared for the 1.8T I plan to put in the Passat once this swap is complete.

 

GoremanX

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2001 Audi A4 Avant quattro w/BHW TDI & 01E 6-speed
I take it back, this engine isn't simple at all! That's quite the collection of stuff all stuck together in super right quarters. I rounded one of the allen head bolts that hold the EGR cooler to the intake manifold (the one behind the turbo actuator), and I somehow managed to break the tip of an allen key INSIDE the head of one of the other bolts... flush with the bolt head, of course. It's a wonder anyone can get anything done on these engines while they're installed. A turbo swap looks like one hell of a job. I can't even get the turbo off without removing the entire exhaust manifold.

Good times!
 

Ifixit

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Waitsfield, VT
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97 B4 Passat GLX TDI Wagon & 99 Golf & 05 Passat 4motion Manual & 04 Audi A4 Avant
Good progress nice work!
Back on the engine control subject, using the passat engine controler should not be too hard
Cruise control switch pins need to be connected directly to the ECU not via can
ClimaTronic is only a few wires and definitely will work no problem
ABS should not be too big of an issue, your car does not have traction control correct?
Your tuner Will be able to set up your ECU to be coded for manual transmission as there are no manual code blocks in the BHW ECU from the factory
You may also need him to disable some fault codes for annoyance codes that turn the light on due to missing messages from other control units
Not sure about airbag control module
Have fun!
 

GoremanX

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2001 Audi A4 Avant quattro w/BHW TDI & 01E 6-speed
Back on the engine control subject, using the passat engine controler should not be too hard
Thanks! That confirms most of the info I got from tdtuning. You're correct, I do not have traction control on my A4 (and I'm SO glad about that). So I guess I'll be using the Passat harness and ECU after all. Sweet, more money saved :D

I've got the engine mostly apart now. Just stuck on the crank bolt. I don't have a breaker bar long enough, so I need to acquire some pipe to make it longer. Stupid thing to get stuck on...
 

GoremanX

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2001 Audi A4 Avant quattro w/BHW TDI & 01E 6-speed
Meh! Turns out I just wasn't pushing hard enough. I was trying to counterhold the pulley with one hand while pushing on the breaker bar to remove the crank bolt. Once I got the counterhold supported with something else and used both hands to apply pressure on the crank bolt, it came right off.

Finished disassembling the engine today, woohoo! Tomorrow I'll be bringing the short block to the machine shop.



A few observations:

- This engine has 220,000 miles on it. None of this engine has ever been taken apart

- 2 camshaft lobes were worn, but not excessively so. I would've felt confident running the engine a while longer before replacing the cam

- All cam followers were in perfect shape, even wear, no ridges, no concave surface

- Still had the original chain-driven BSM. No slack whatsoever on the chain. A couple of broken bits on the front plastic BSM cover. Chain tensioner was still perfect. The hex shaft that drives the oil pump still had perfect fit inside the pump, but was extremely loose at the other end. Probably would've failed eventually.

- Piston clearance looks good upon cursory examination, but the machine shop will confirm that for sure. There's barely any ridge at the top, I could probably get the pistons out without reaming if I really wanted to. But I'll let the machine shop deal with that

Once the machine shop confirms whether or not I need new pistons, things should really start moving!
 
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TrekSportMK3

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Feb 27, 2012
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Johnson City, TN
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none yet :(
balance shaft and oil pump

Just my .02 but while you have the engine out it would still seem like the best idea to do the balance shaft delete and run the alh oil pump... considering price for parts and the known failure $4-500 seems a small price to pay for security. I dont have the funds or time to do this but obviously me reading and replying means this is a dream i have for my quattro avant, keep up the good work!
 

GoremanX

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2001 Audi A4 Avant quattro w/BHW TDI & 01E 6-speed
That's already planned, and I discussed balancing the rotating assembly with my machinist. He thinks he can get it to within just 1 gram @3", which is better than I could've hoped for.
 

GoremanX

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2001 Audi A4 Avant quattro w/BHW TDI & 01E 6-speed
Now this is a conundrum. Trying to get axles for my swap, so I called up Raxles. But they won't sell me any S4 axles (which is what I need) without cores to trade, and cores are rare as hen's teeth. Not the cheap Chinese crap, but unmolested Audi cores. Where the hell do I find those?

edit: after further research, I'm more confused than ever. Why, exactly, would I need S4 axles? The 01e 6-speed manual transmission I have uses the same 108mm 6-bolt flanges as the 01a 5-speed it's going to replace (or does it? I get conflicting info about this). My A4 has 33-spline hubs up front, but S4 axles have 38-splines. The compressed lengths of each axle are within 3/16" or less of each other (S4 vs A4), with the S4 being the slightest bit longer in each case.

So why can't I just use A4 axles?
 
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