View Full Version : My 01.5 A4 Avant: The Slow Ascent to Road-Worthiness

07-30-2018, 03:57 AM
Welcome, welcome. This thread will be an opportunity to document my attempts of returning a one-owner Avant with fairly low mileage back to the road. As this color and options may be one of the most common combinations known to man, I refuse to let a good B5 Avant get sent to the scrap yard. B5's across the board are becoming fairly uncommon given similar mechanical issues and age, and I think this late production B5 Avant is worth saving. A little history...

Once upon a late evening in March 2016 I spotted a 2001 A4 Avant with approximately 115,000 miles listed by a California dealer. The car appeared to be very clean with one previous owner, full maintenance history and only needing some minor maintenance; with Dieselgate progressing and my 2011 Jetta Sportwagen soon to be bought back, this would be a perfect daily and keep the miles off my USP Avant. It had a slight ding on the fender and a missing front valance, but I had to have it.

Original screenshot from the ad

I contacted the dealer and made the purchase sight-unseen, arranged transport and had it shipped to Portland from the Bay Area versus driving it home. Four days later it arrived from the transporter and I could not believe how clean the Avant was. The transporter and I pushed it off the trailer due to a dead battery, eagerly jumped it with my TDI and discovered this thing billowing white smoke like a big rig doing a DPF regen.

Regardless, I was happy to see itsí condition.

Tore it apart, quickly found a large amount of shaft play in the turbo, and an impeller wheel appearing like it had foreign object damage. Found a used K03 from a 2002 A4 from a local dismantler, tossed it on and everything was great.


Fast forward to approximately 800 miles of trouble-free operation after turbo replacement, I heard an audible chime from the instrument cluster (okay, it needs an LCD too) while cruising down the highway; upon pulling off the highway in Portland it sounded identical to my TDI and I knew something was really wrong. Left it in the parking lot, walked about two miles home and came back about a few hours later once the car was cool. The benefit of letting it cool down? I could now see what symbol the instrument cluster was attempting to display.


Started it up and drove it home, no noise at this time. I decided the next day to remove the valve cover and see how things appeared internally. Typical early 20V sludge; things did not look promising.

After towing it to the shop, I decided the motor and all components were not worth saving. The used turbocharger was destroyed, almost-new timing chain tensioner was rattling, and I just said screw this. Typical B5 sludge problems.


From the documents provided with the car, the one previous owner purchased this new from Butts Audi in Seaside. 200+ pages of all-things maintenance and history, including bank statements, window sticker, and original Audi Club NA membership.


Goals for the car...
Clean, OE in appearance while running a 1.8T and K04-064 turbocharger on a rebuilt 1.8t and 02X 6spd manual. Using the VAG parts-bin to incorporate OE upgrades for the car such as a single serpent-belt setup with AC, improved cooling upgrades, and lubrication too.

Part 1: Finding a motor (December 2016)

Considering all options while the car was stored indoors, a 2004 Ultrasport Sedan with 99k miles and a fair amount of body damage was bought for the motor. The bonus? Less than 43k miles on a replacement motor installed by a local Audi dealer.


AWM engine removed

Summer 2017: Donor motor removal and bay cleaning

The B6 donor sat parked for a few months indoors until summer break, where I lifted up the B6 and removing the drivetrain.




Minor engine bay cleaning after


Spare 02X? Sure, let's make it fit!
With a complete 02X 6spd mated to the AMB, I decided to give this an attempt at installing this transmission into the B5 and ditch the 01A 5spd. Initial pictures seeing if it fits...



Barely fits, but it fits.

Linkage swapped over to a B5 skeleton/shift box:


Linkage bolted up

Shifting' gears: a 37% reduction in shift throw over the stock 01A. Free short shifter, and bye-bye notchy 01A!



With the trans in the car (okay, held by a bottle jack) we decided to design or construct ideas for the trans crossmember. B6 and B7 cars use a DTS-style trans crossmember. After many months and one of my best friends coming to the rescue, we now have a jig made and a crossmember made to fit the 02X to a B5. I'll have that back from powder coating this week.

Winter 2018- current

With the motor and trans installed in the car, I wanted to try a few things. B6 1.8T and B7 2.0T motors use snub mounts that attach to the oil pan, the exact opposite of B5 cars. With a spare B7 intercooler tube laying around, decided to give this a try:



Perfect. This will allow me to run a B7 A4 oil pan for increased oil capacity (more on that later) while running OE SMICs.

Serpentine belt setup-

With a complete 06A AMB belt setup, I wanted to run a single serpentine belt. Only hurdle was the AC compressor- B6's use a completely different clutch assembly/mechanism that is not compatible with our B5 cars.

Solution? 2.7T motors have their AC compressor in almost the exact same physical location within the engine bay.

2.7T compressor and hoses from my B5 S4 parts car


2.7T compressor installed and bolted up

Compressor lines installed. Perfect clearance of swaybar and oil pan

Complete setup. Proper length 6PK1590 belt will be in tomorrow morning

More documentation and uploads to come tomorrow of my log [:)]

08-01-2018, 07:37 PM
Awesome, and subscribed.

ĎThe sports sedan with a fanny packí

Love it.

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08-02-2018, 07:00 AM
Great thread. I kept going "but what is he going to do about the...Oh, OK. I see what he did there." [up]

08-02-2018, 12:50 PM

08-05-2018, 05:43 AM
those are some really clever oem modifications that Iím sure not many people have thought of doing

08-05-2018, 06:31 AM
Considering all options while the car was stored indoors, a 2004 Ultrasport Sedan with 99k miles and a fair amount of body damage was bought for the motor. The bonus? Less than 43k miles on a replacement motor installed by a local Audi dealer.

Well I'm not sure if that's a good thing...or a bad thing [:D]

Great thread!

08-05-2018, 02:30 PM
What's up Tyler!
Looking forward to the progress on this!

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08-06-2018, 01:14 AM
Haha what's up David!

So let's see, left off at the serpentine belt... I wanted to update this for anyone looking to go single serpentine belt while retaining AC. My entire AC setup from the firewall forward is from my 2001 S4 parts car.

I removed the old lines that enter the cabin a few days ago, along with the AC dryer bracket mounted to the RH frame rail.

1.8T items


S4 AC lines installed


Removed from the S4 donor are the intercooler brackets. The passenger side bracket attaches the AC dryer and adjacent hard-lines.


Temporary mockup. Ordered 10 rivets for both sides (only 7 needed, few extras wouldn't hurt) from my local dealer. No drilling necessary; I will do a final install here this week once everything in the bay is removed and cleaned.


Now with everything mocked up regarding the AC, I tossed on the new serpentine belt. Belt used is for an early B6 1.8T (6PK1590) and is perfect in length. Ive always used Contitech but their belt was backordered and selected an Optibelt. Made in Germany, quality is great (and packaging too).



Last piece of the belt setup- power steering fittings. For those seeking this setup, 2 options: 1) use your existing 1.8T power steering pump with a Mk4 VR6 pulley, or 2) a B6/B7 pump. Changing the PS pump hardline is not necessary, as the B5 1.8T line and banjo fitting fit perfectly with either the B5 or B6 low pressure line.

Pump mocked up and checked off the list

With all of the accessories taken care of for mock-up, next step is teardown of everything forward of the firewall and clean everything. More updates to come this week :)

08-06-2018, 01:17 AM
Well I'm not sure if that's a good thing...or a bad thing [:D]

Great thread!

Haha exactly. It's a factory rebuilt Audi long block, but there were a couple questionable things ill elaborate on later; needless to say I will be completing a fairly thorough check as I install the AWM specifics and make sure it wasn't tossed together on a Friday afternoon [;)]

08-06-2018, 09:47 AM
First off, great thread.

Second, I am the only one that noticed 3 different turbos going on?

You go from a k03 to what appears to be a frankenturbo with a transverse engine compressor cover, then in the below photo changing to some sort of FSI/TFSI k03/4 revision? What gives?


08-06-2018, 12:36 PM
When I picked up the B6 parts car I had a TT225 (K04-23) turbocharger at the time. Sold it and took the plunge towards fitting a B7/Mk6 turbocharger without hacking everything up, and having it fit like an OE setup. In the pics you see a K04-064 from a Scirocco R, and that's what I will be running with an upgraded comp wheel. I will take a bunch of pictures today showing what's needed and include an Excel spreadsheet for everyone too.

08-06-2018, 09:33 PM
Wow, great progress.

I was not expecting this amount of work.

08-12-2018, 11:24 PM
Thanks Memo...tends to be the downside of being OCD.

Back to the B5, been a touch hot and even warmer in the shop. Progress has been at a slower pace than I would've wanted, but things are moving pretty well.


Passenger side wheel well looked good, not really any surprises


Driver's side was the opposite; I was curious where the PS fluid was going since it's been sitting. Probably all too familiar to the B5 community


With the B5 S4 parts car just about to depart to the scrapyard, I checked out the steering rack and removed it. A4 rack on top:


While comparing lines I found what appears to be the low pressure PS line sweating fluid. This will be replaced too.


S4 rack is in great shape, and perfect candidate to be rebuilt and assembled for the Avant.
With the rack removed and some of the heat shields, started checking out the residual dirt from a car on the road since 2001


Typical road debris; dirt and grime from 115k miles of use. There was a fair amount of buildup on the subframe from what appears to be blown inner CV joints, but not too shabby.

With this pushed out of the way on my lift table, going to finish the bay teardown and cleaning.


This week: clean the engine bay along with all of the heat shields, rebuild the steering rack and continue progress towards a clean avant [up][up]

08-14-2018, 01:16 PM
Good idea doing that steering rack with the drivetrain out. [up]

08-17-2018, 10:44 AM
Curious to see how the steering effort will be affected by the S4 rack. Back when I had my first B5, I installed a 1.8T rack into my 2.8 (not aware of the difference). Noticed heavier steering at low speeds, I'm guessing there was less power assist in a 1.8T rack due to the weight difference of the engines. Will be interesting to see if there's the opposite effect of more power assist installing an S4 rack into a 1.8T. [up]

Do S4 racks have a different ratio than A4 racks?

08-17-2018, 10:51 AM
10/10 use of the word "Rack"

08-17-2018, 11:18 AM
I don't think the ratio is different. Just the additional damping on the S4 rack, I think.

The B5 RS4 might have been a different ratio.

08-17-2018, 12:15 PM
I think Ben is right, but I would love to know the differences between an '01 S4 rack, and the A4 rack. The price difference when purchasing a rebuilt rack from say, Rackdoctor, is quite substantial. 1.8T racks for 00-01 MY A4's are $199, and the S4 is $339.

Edit: I can't read

08-20-2018, 02:24 PM
Dat PS pump do. [up]

08-25-2018, 01:31 AM
Haha, whoever used blue shop towels as fluid stoppers is the homie.

Progress kinda went at a snail's pace with our great weather and wildfire particulate matter essentially ubiquitous in our region of Oregon. None the less, got things a little more sanitary in the front end.



All the heat shields cleaned. I mangled the RH tunnel shield, NLA and presently in search for a clean replacement. From the B5 S4 parts car I kept the passenger side lower frame rail heat shields. They cover the fuel lines very effectively, nice little bonus.

A little before...


And after.



Parts for the rack showed up. Went with TRW inner and S4 outter tie rods. Also replaced all the Oetiker clamps and banjo bolt washers.



Other than coilovers, this was my most speedy purchase to date. Replaced both power steering pressure lines given the age and loss of fluid seen from the low pressure line.


With new hardware for the shields and rack, started reassembling things. Shown are the passenger side S4 shields installed, provides a nice barrier against exhaust heat


Everything was going dandy until I ran into this snag- managed to break the rivet gun. Warranty replacement should be here tomorrow morning so I can finish up both intercooler brackets and check one thing off the list.


More updates this weekend before class starts [up]

Edit-bad image link.

08-27-2018, 09:27 AM
That wheel well is clean enough to eat off (the whole car is really, tbh). [up] Jealous of the overall lack of rust... keep up the good work!

08-27-2018, 09:37 AM
Damn. I love clean projects.

10-21-2018, 02:57 PM
Oh yeah, updates.

B5 S4 DSMIC brackets are all in, mocked up the old AC dryer for now and will install the new one when the motor is finally back in the car.


Since I will be running the S4 aux fan up front, cleaned up the S4 harness and module, and re-wrapped the electrical tape portions



While finishing this up, noticed there is a difference in the ABS module brackets between the 4cyl cars and the 2.8/2.7T V6 cars; not all of the connectors can be secured, so I will source a V6 ABS module bracket this week so I can check this off the list


Not to confuse anyone, but while I wait for the last few engine parts to come in so I can do my final drivetrain refresh and assembly, thought I would share my little adventure in making a FSI/TFSI turbocharger fit...

I will be running a K04-064 and have one from a Scirocco R that I've been using for mockup purposes. All of the Volkswagen/Audi 2.0T turbochargers (2005 thru 2013) use a 4 bolt turbocharger discharge flange that is quite massive, and would not fit with the stock RH motor mount bracket. Going through the VAG parts bin, believe I found a solution:



B7 A4 RH motor mount bracket. B7's have a motor mount bracket that is recessed to accommodate the larger flange, and bolts up to an 06A block without modification!


Next up, turbocharger support bracket. Disassembled the turbocharger to make it easier to see: support brace and black metal bracket secured to the block both fit without modification, and are B7 A4 parts as well


And how it all looks in the car



This is an older picture prior to AC lines, but gives you an idea how everything can be routed...should be able to run a B7 turbo inlet pipe and have a fairly stock looking bay


Let's see what I can get done in the next few days off...It's crunch time.

Edit- last image

10-22-2018, 07:11 AM

10-22-2018, 09:29 PM
I'm very interested to see the performance of that turbocharger.

I'm glad some B5s still get love.

10-22-2018, 11:27 PM
Ya know it shouldnít be too bad...Mk6 Golf R/Scirocco R turbochargers are fairly large; for example the comp wheel of a GT2860R aka GTRS is 46.5/60mm whereas the K04-064 is 46.3/59.6mm, but the nice advantage of the 2.0T Borg Warner turbochargers is their twin-scroll exhaust manifold that really helps to reduce lag. This turbocharger setup is fairly common on transverse 20Vís over in Europe, where you see many over the 300whp mark in 2wd fashion. Add a billet wheel (which I may do) and I think we could achieve 300awhp.

None the less the B5 will always be my favorite generation of Audi, specifically in Avant fashion. It has the minimalist electronic gadgetry offering basic safety and creature comforts, but does not hinder the driving experience. This was a big motivating factor towards saving this car. [up]

Joe Jr.
10-23-2018, 02:54 PM
yeah man, holy no rust bucket. like the project!

10-23-2018, 11:16 PM
Wow, I really like that turbo choice.

But what I've heard is that the fast spool and aggressiveness of the tune is what can cause even a k04 to bend rods.

A gt28 is considered "kind of safe but pushing it", but with a faster spool, maybe not so safe. Have you considered this?

10-24-2018, 07:00 AM
I guess I didn't realize these turbos bolted up. I thought an adapter was needed, but maybe that was for the TSI turbo's.

10-24-2018, 07:12 AM
Which K04; K04-015 or K04-064? Most of what Iíve seen from across the pond with guys running the K04-064 is that a majority are on stock internals, and I think a lot of this has to do with the power delivery being a touch more linear without the hard torque spike that is down low with K04-015 turbochargers. And youíre definitely right about tuning- for now this motor will be on stock internals, so I will have a fairly conservative tune, plus we only get 91 octane here in Oregon.

I guess I didn't realize these turbos bolted up. I thought an adapter was needed, but maybe that was for the TSI turbo's.

But yeah, cool thing about the BW integrated manifold turbos found on the B7 A4 is theyíre very cheap. You can either go with an adapter from INA ($300), or bolt it up with brackets. So far Iíve had brackets made, but both ways work and it is a 99% bolt-up option.

So for about $150 in a used turbo, new CHRA and misc other parts you can have a drop-in turbo that is larger than the K04-015 but giving you a much more linear powerband for under $750. Iíll load my excel file of turbo PNs here later today.

Edit- this is the similar style of bracketry I went with; spent less than $15 in materials and had a machine shop cut them to my specs for a grand total of $70 including materials.


10-24-2018, 10:50 AM
Very cool! Love the OEM parts bin galore, and I think we really have something here with that K04-064 setup. FT power, with reliability? [>_<]

I personally went K04-015 since I snagged one for super duper cheap, but from advice from others, i'll be running an MBC in parallel to the N75 to eliminate potential harmful boost spikes [o_o] AEB rods are a little stronger, but not super lol.

Wow, I really like that turbo choice.

But what I've heard is that the fast spool and aggressiveness of the tune is what can cause even a k04 to bend rods.

A gt28 is considered "kind of safe but pushing it", but with a faster spool, maybe not so safe. Have you considered this?

People have gotten away with F21 on 91 with stock rods, so maybe ok? Depends on tuning/your luck I guess [rolleyes]

Real curious to see how the K04-064 stacks up against an F21 though.

10-24-2018, 03:57 PM
This is great. Love the attention to detail.

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