2.5L AEL TDI with 6-speed manual swap into C4100 Avant

[mogly]

It sounds like you've hit the swap plateau blues Dave! I feel for you. I've been there myself. I find that with swaps that I work in "spurts", as in, heavy motivation and good progress then a period of inactivity but with a regular life and family obligations, extra time can be hard to find/make.

My B5.5V was completed in such a manner. I started with an '02 shell and an '05 wagon parts car. Figured there both B5.5Vs should be the same, right? Wrong! MANY subtle and seemingly insignificant differences that represent a lot of work to make "correct".

I have found that taking lots of pictures and when you "hit a wall" then pull up your pics and have look through and see your progress. I find it helps make you feel a bit better and the end just a bit closer.

Keep it up!


Rob

 

[DangerBoy]

Well, a quick update everyone on my progress. I have no idea how many hours I have into this project now, but it is a really large number. Since my last post I have done the following:

Extensive wiring. This includes removing all the phone and disc changer wiring that was in the C4. I went through the BOSE amplified speaker setup and realized that it is really easy to make that system a non-single-ground-wire setup... the point where the connection is made isn't far from the head unit and the car is actually not wired with it as one wire, even though the wiring diagrams don't say so. I did research online and everywhere I looked it was considered a problem that had to be accepted but it wasn't true. Hopefully this information helps someone else that deals with modding the sound with this car.

Anyway, so I soldered in the new head unit's wiring so it will all fit neatly and not have excess everywhere. Also I was able to retain the Audi handsfree microphone and rewire it to work with the head unit. Hopefully it works well. It is nice that I don't have a tacky looking mic hanging around like I've seen in many cars. My goal with this project is to keep everything very professional and factory in appearance. I removed and dismantled the BOSE rear subwoofer assembly, at this point I discovered that it truly is a two channel unit and was able to wire the head unit to support it properly. In a nut shell the whole system has it's own amps for each speaker and you only have to provide line out to each. The rear sub and rear door speakers are all fed by the same rear signal and that is totally fine with me anyway. All the wiring for the sound setup is very clean now, I hope it sounds good!

I largely dismantled the AEL engine. Swapped the crankshaft seals, camshaft seals, ultrasonically cleaned virtually every part that comes off. New timing belts, went through the power steering pump, alternator, vacuum pump, transmission slave cylinder (holy smokes was that corroded inside! This should be cleaned or thoroughly flushed every couple years IMHO). All of that stuff is back together and the engine/transmission is now bolted back together ready to be put back into the car. I bought a OEM cyclonic air/oil separator from a guy in Germany on Ebay.de (Had to use google translate to even communicate) it arrived, I threw it in the ultrasonic and it's now mounted.

Just tonight I finished mounting my Webasto diesel fired coolant heater. I'm really pleased with how that went, I used some spare line that came off the gasser A6 to run back to the tank for the dosing pump. It will be very nice to have this on the car to save the TDI from cold starts. It sure worked great on my CDI smart fortwo. The full interior is still out of the car so I can wire everything in and keep it OEM style. For example: My daytime running light circuit I added from the Canadian Spec A6, since the Diesel wiring didn't have it. Well, the diesel wiring didn't have a bunch of things so I had to make new harnesses after going through literally hundreds of wires.

Anyway, the daytime running lights put 12V through a resistance wire so the headlights (low beams) are dimmer and that is what is on when the headlights switch is either off or on parking lights. I rewired the system by taking relay sockets from the spare A6, pulling the pins from the relay sockets, color matching and using appropriate diameter wire for the relay socket, changing the circuit so the fogs get the resistance wire when daytime running lights are on, and then when actual headlights are on the fogs get the power redirected through the proper switch on the dash. This was all in effort to save my HID headlights, which I pulled from a Honda S2000. They will only be getting full 12V and this is only when the headlight switch is are actually on. Since I used an OEM relay socket, I put it in the appropriate location in the Auxiliary relay panel 1.

The Webasto heater I am installing I'm also wiring this way, using OEM fuses and relay sockets so I can put in into the OEM wiring (though a seperate harness) and have it all look factory. In the end it doesn't matter I guess, but since I have the car completely dismantled I figure if I'm doing it why not do it as good as I can right?

I did some other little adds to the wiring, added the adjustable headlight circuit, the button operated window wiper control circuit, rewired the gasser cruise control and added the necessary pins to the OEM ECU so it will all work. I just finished changing the wiring so the car will actually tilt the mirrors when I shift the manual in reverse. This was easy to do once I figured out how the Manual and Auto differ in wiring. The Auto has this circuit in the Auto transmission wiring harness, and the manual has this in the main harness. I pulled the wiring from the Auto harness and made a simple little stand alone harness for this so it would work as it should for manual trans setups.

My Curt hitch came in and I've started to mount it as well. It is ready for drilling but I'm going to wait until I'm ready for doing more undercar painting before I do so I can repaint the holes so I don't get rust from drilling through. All that being said the Curt hitch fits perfect and I had it sent with a euro style drawbar which looks much cleaner.

So here is one interesting tidbit, did you guys know that on the C4 A6 the diesel HVAC system has an electric auxiliary heater core? I'm glad I had an entire TDI car here for my swap otherwise I wouldn't have known to swap that!! I bought a new heater core online that has the proper size connections (BEHR/Hella I think) and put it in while I did the swap. The donor TDI had been in a collision and the HVAC fan housing had been broken so I needed to swap the electric core and wiring over to the Gasser HVAC unit. Other than the hole for the wiring everything else was direct simple swap.

I cannot believe how expensive that OEM 01E transmission oil was! I figured I would swap out fresh fluid since I had everything out.

I hope to be able to post in a week and tell all of you how the car is back together and running... but at this rate, it may be much longer. When it is done, it will be one awesome efficient car though.

 

[DangerBoy]

Here are some photos:
Webasto Install:

Curt Hitch Install (mind the spare parts I'm storing under the car, space is getting limited with so many dismantled cars):

New heater core and wiring to electric core, all sealed and ready for install:

Main electrical harness wiring:

Inside of the car with harnesses installed. I just finished the Audio system wiring. It is actually pretty much finished with the exception of the Webasto wiring... despite how not complete it looks. Mind my white fabric tape I used on the harness instead of black. Makes it easier to see what I did and easier to see in general:

I've also pulled the trim from the other car already to put in the place of that wood grain stuff in the car now, just not my cup of tea. The other parts I have are aluminum but have a dark pattern on them, I'm not sure how it will look. Anyone have any advice on putting a brushed finish on those aluminum parts instead? Just fine sandpaper and clearcoat? Or just fine sandpaper and nothing? Some sort of "brush" to do it? I know nothing of how brushed finishes on metal are achieved. I'll google it after I'm done this!
Engine crank seals swapped, oil pump cleaned and reassembled, various engine parts cleaned and mounted:

This really puts things into perspective as to how the engine looked before:

Most of the stuff on the engine was from the mickey mouse rigged oil separator that was leaking all over the place. All of the OEM parts that were missing or broken were sourced, cleaned and mounted. Hopefully it will stay much cleaner now.
Engine now:

You can see the new cyclonic separator in this shot clearly. I should have taken an after photo before I mounted the turbo... the metal lines that feed and drain the turbo and go from the coolant pump to the oil cooler as well as the cyclonic lines look like new:

(Sorry the image needs to be rotated, I couldn't figure out how to do it in imageshack, on my local it is rotated already, but somehow only the raw file is sent to imageshack.)

And just an overall engine/trans shot. I've been fighting the urge to totally dismantle everything, get everything recoated and the whole nine yards but I'm winning that battle right now and just trying to get the car back together.

I'm really pleased to read that the older 5 cylinder diesel's were the best for fuel economy as compared to the newer V6's. As I mentioned before I hope to build an adapter or perhaps a new manifold with the VNT turbo I picked up but for now I'm just focusing on getting the major stuff taken care of and I can come back to that at a later date. I think getting the Webasto on at this stage though was a great idea, my unit has the 2-way remote on my keys that allows me to start it like a command start so the car is warm inside with the engine preheated before I trek out to it.
This is nice because one thing I don't like about VAG cars is the heated seat dials. If you were to have command start the heated seats would kick in with everything else (unless you wired it to not activate that circuit I suppose) if you left them on. The Webasto bypasses the fan wiring with a relay and gives reduced voltage to the fan only so it blows on whatever directional setting you had the climate control on last. Nothing inside the car actually turns on besides that. It is pretty elegant really... as it heats the car up the battery also gets some heat since it is in the car, and starting should be no problem.
I'll be posting again soon!!

 

[DangerBoy]

Here are a couple shots of the intake manifold and it's adapter. As you guys know the intake of an EGR TDI get's completely filled with soot, I don't have any before photos, but here are the after ultrasonic cleaning photos:

It really does an amazing job.

 

[mogly]

Making some progress! I like the webasto heater idea. I wanted to do one with my B5.5V but couldn't find one at the time. Where did you source yours?

 

[DangerBoy]

I've made some really good progress today, wiring is finally done with all the Webasto related items integrated into the Audi climate control harness. I decided to wire the unit different than they recommend, rather than isolate the fan with two relays and use a resistor to slow it down I decided to isolate the power to the entire climate control system so when the webasto kicks in so does the climate control. This way the car automatically will heat the interior appropriately but more importantly it is more efficient use of electricity. I found it interesting that the heater blower motor in the Audi doesn't use resistance to change it's speed, but rather it uses PWM like servo drives do. I like the fact I'm not wasting valuable battery energy to waste resistor heat and it is almost all going toward running the fan at the appropriate level. Also the fan will not kick in until the engine is sufficiently warm, which I prefer. I would much rather have a little chilled interior in a pinch than the engine still stone cold.

As to where I sourced mine from, my '06 Diesel Smart Fortwo already had it installed when I bought it. I bought the whole car for the cost of that heater unit, so I knew I would come out ahead when the day came I sold the Smart provided I removed the Webasto prior to the sale. The unit I have (Thermotop C) is way overkill for the smart, it's coolant lines are the same size at the Audi and had to be reduced for the smart. I look forward to seeing how well it works on the AEL TDI.

I now have the carpet back in the car as well as the main heater core/fan housing is mounted. I wanted to have that all in place before I put in the engine since it is much easier on the back to work on the HVAC when the engine is out. I think everything is going to progress pretty fast now that I don't have to build or mod anything else. I just need to resist the urge to recoat all the suspension parts. I'm keeping a spare set of suspension for powder coating and rebuilding later... then maybe next year I'll swap it out. For now I just want this car and it's AWD for the blizzard we just had come through here!

 

[DangerBoy]

To my fellow TDI enthusiasts: I have a problem to which I think I have formed a solution (pardon the pun you will see soon enough) and I want to know if anyone out there has any feedback or experience on it.

My AEL TDI block has some rust in the water jacket and pretty much coating every part of the coolant system that was on my sedan. My Webasto, a bunch of my heater hose, my heater core, my expansion tank and my radiator are all in great shape being either new or from vehicles that were well maintained. I've tried ultrasonically cleaning what I can (the hoses for example) but ultrasonic cleaners don't work as well on rubber parts and my cleaning solution isn't that aggressive towards rust.

So here is my proposed method of cleaning what is dirty in preparation prior to hooking it up to all my other good parts:

First, buy some phosphoric acid from Home Depot, the stuff they sell for cleaning concrete (BEHR PREMIUM Concrete & Masonry Cleaner & Etcher, 3.79 L)

Next, attach my stainless steel hot water heating elements to the container I have the acid solution held in to heat it. I have a couple of these with thermostats from another project so that doesn't add to the cost. 2000 watts of heating power for a couple gallons should get the job done quite quick.

Submerge my swimming pool clean out pump (Also from another project) in the acid and attach hoses with adapter fittings to the existing rad hoses from the AEL engine. At this point I've already removed the thermostat, the engine is only connected to this setup and none of the non rust filled parts mentioned above.

Put an aluminum plate in the heated bath of acid and attach a battery charger to it and attach the positive to it and the negative to the engine.

Once all of this is in place:

Heat the acid, start pumping into water jacket of engine while simultaneously applying current through the battery charger. Periodically dump solution back into tank, inspect engine for rust and repeat until clean. Flush engine with water and attach to vehicle as normal.

From my research Toyota coolant uses phosphates for corrosion protection already so I'm assuming anything more than a water flush would be unnecessary after this process.

Has anyone out there tried anything like this? I think it would likely be the most effective and safest way to clean the entire system without worry of metal attack and lack of cleaning action. I am going to take many photos and document this process for others. I'm sure if it works it may be helpful for others in my situation.

At first I was feeling really depressed about having to deal with this problem but now I'm excited, I think this may work well! It is both a chemical and electrical cleaning process that will not hurt the aluminum (in theory).

 

[mogly]

Oh, I see. I didn't realize it was a retrofit and not a "kit". Nicely done. We have one in our Sprinter and love it.

Regarding the coolant corrosion. I don't have any direct experience but your idea seems sound. I'd just be certain that you neutralize the surface afterwards. I know there are products specifically made for cleaning oil residue such as from a failed ATF cooler or other oil intrusion but not sure if there are products geared to your needs? It certainly makes sense to attack that now before contaminating your fresh/new components.

 

[DangerBoy]

YEAH!

So, the car is running. Set the timing via VAG COM, did it while running and got it bang on after a couple taps with my polymer impact hammer. I don't know enough about how TDI engines like to be advanced or retarded so I figured I would aim for what the software told me and leave it at that for now.

The Webasto works too! This is a relief since my install didn't follow half of the recommendations of the manual. I didn't use the plastic line they tell you to use, instead I used a line that came off the gasser that runs with the OEM fuel lines and puts the dosing pump right where it was supposed to be with the Webasto option shown on ETKA. Getting the fuel system free of air was fun, took a few tries and creative approach but eventually the unit caught and we are good now. I didn't wire it like the manual says, instead I bypassed the power to the climate control via a relay so the entire climate control would come on when the Webasto signals for it. In actual testing this works extremely well... when I push the button on my remote, the unit fires up and starts circulating the coolant. After the coolant reaches a certain temp then it signals the relay, and then obviously the climate control comes on. The whole operation runs flawless, I'm pretty surprised... I was starting to wonder if all those wiring mods were going to work out or not... The way it worked in the smart car was much less optimal and I'm glad it's this way now.

I put in a slick aftermarket head unit, the factory Audi mic for handsfree didn't work with the unit so I installed the head unit mic in the factory position and from inside the cabin it all looks stock. I tested the unit and it works great! Now, as far as the Bose amplified speaker issues: I read online about other people that have the same head unit as me (JVC KD-AVX77) trying to run the RCA outputs to the Bose amps since the speakers have their own. Well, this doesn't work and it ISN'T because of the Bose system. The head unit itself is flawed... the extremely loud POP and CRACKLE noise it makes when you do pretty much any menu item change or power down is very annoying and probably damaging to the speakers. Once I split the wires to non-common ground (Like I mentioned in an earlier post) and then wired those to the regular speaker outputs from the head unit, all I had to do was lower the internal amp setting and the whole unit works great. I am quite impressed with the sound quality when you consider how small the speakers are... there is some decent bass! I have a couple 1000 watt Rockford Fosgate subs with big amps sitting in my basement I was going to install, but I really don't think it is necessary.

This project sure was a large one. Very time consuming for a single person... I can understand why so many do not finish before they decide to throw in the towel. All that is left for my project is wiring in my Honda S2000 HID projector lowbeams and I think I'm done, besides getting all my missing parts for the A/C system. I'm not going to worry about that unit spring though. I already checked my wiring and the headlights work as intended, fogs on lowered voltage for daytime running lights, low projectors (HID) for headlights on, lowbeam, and both low and highbeam for highs. I also have the adjustable headlight level that came with the Euro car though I can't confirm if it is functioning yet.

I'm pretty happy with how well the engine is running, it is very smooth and quiet. After all that time spent cleaning the entire intake system and turbo, I hope that it has found some of it's lost power. I probably will not be able to take her out for a couple more days, but I'll be sure to post how it goes and take some pics. We just had a big dump of snow here again so it's great quattro weather!

 

[DangerBoy]

At last, the car is finished. The S2K HID headlights are amazing! I'm glad I added the headlight level control because now I can set my lights a tad high and then just dial them down for in town daily driving, but raise them a little for highway and still get the HID light for seeing down the road.

I'm not sure exactly what of the many things I repaired with the engine's intake/turbo fixed the lack of power but now the engine makes plenty. Once it spools up it really goes quite well and the traction is excellent. I have winter tires on her now and although it is snow and ice outside you would never know it driving that car... it just goes like it was dry outside. That alone had made this project worth all the work. Another nice thing about the A6 vs any of the other diesel vehicles I've been in is the noise level. This car is so quiet especially on the highway, and the 6 speed sure is geared tall. This is the ultimate highway vehicle, in my opinion.

I'll post some pics of the finished car soon. I hope at least a couple people out there found this swap over to be of interest!

 

[alphawerks]

Congrats on getting it on the road!
I for one have been following with interest. Good effort!

Ryan

 

[00quattro00]

Did you get around to installing the t4 ecu and vnt turbo? Im about to rip out the 20vt from my s6 and replace it with an ael, ideally with a vnt

 

[DangerBoy]

As good as bad news gets!

Hello everyone, seems like a very long time since I've been on here and posted. Years ago in 2013 I completed my Audi C4A6 AEL swap and this past Wednesday I came within a hair of losing my life in it.
Someone, the case is still under investigation, decided to try to outrun the police and my Audi with me inside happened to get in the way. Luckily I was pulling my trailer at the time with a walkie forklift chassis loaded laying on it's side with the main lifting mast running longitudinally with the trailer. When the SUV hit me it was going about 100km/hr faster than I was. I looked in the mirror and saw headlights coming at me so fast I was positive it was the end. After the initial impact I was amazed to still be watching the show! It wasn't over... the impact pushed me toward the oncoming lane up over the curbing about to head on collide with a bunch of oncoming traffic. I slammed on the throttle and turned hard right and the Audi quattro system dug in on that grass and got me back in my lane. At this point I already had a flat rear right tire and crushed trailer with a missing right wheel. Came to a stop, some issues of course but I was still alive and able to rush over to the other car to make sure they weren't bleeding out or something. The car had gone down into a deep ditch and no one was inside. How they managed to get so far I couldn't see them even though it had been only a minute or so since the crash I'll never know.
ANYWAY... so here we are. Best case result out of a bad deal. Audi is salvaged yes, but nothing is damaged on the car that pertains to the TDI or drivetrain. Really it's just the rearmost portion of the car and even the rear suspension doesn't seem to have been damaged. I was able to drive it up on the car trailer... flat tire and all.
So now that I lived with the car for a few years and loved it immensely I am deciding what my next move is. My only gripe with the car was how large it felt and long compared to something like an A4. The suspension was very soft and those leather seats were so slippery even the most minor sporty driving had me moving all over the place. I had an A4 with the sport package and a special sort of cloth seats and I loved those. I'll never do leather again, looks great and cleans nice but not for me.
Another thing I didn't like about the car was the really bad turbo lag compared to a VNT. I already bought all the Transporter TDI van parts that allow me to have VNT such as the exhaust and intake manifolds, though I likely will not use them as they are intended for the van layout, and the ECU with wiring harness. If I swap this again I will go to the effort to add VNT.
Since I last posted I now have German 5 axis CNC machining equipment as well as state of the art 3D scanning equipment so I think making this setup fit in something other than a C4A6 will be much easier now than ever before. I'm leaning toward a 5 cylinder manual Coupe quattro from that 90-91 range if anyone on here knows of one in decent shape. I have the 01E and I think the 5 cylinder engine mounts are shared between the TDI and gasser blocks but that is going off very old memories if anyone else wants to share their experiences on this?
My A6 fan clutch was on the way out so I decided to pull the entire unit and run with no fan at all and see how it behaved. When I raced superbikes we did this all the time so I figured if the temps climb I deal with it but if not I'll leave it. Well even on the hottest summer days in heavy traffic the needle never went over normal temp. Knowing this I am tempted to use a shorter car and just not worry about the space needed for the fan and run the extra cylinder instead.
This marks the end of this specific car, but it will live on as a re-donor (since most of what it will be donating was already donated to it). I'm also open to the idea of finding maybe a Ur S4 or S6 Avant too... basically the same car as I had but better brakes, seats and suspension. All things I would have changed in my car.
The fuel economy I enjoyed with this car was absolutely awesome. It always got over 1000 km to a tank and I didn't drive to conserve. I did get over 1200 on long trips. The AWD with the diesel grunt was excellent in the snow. Everything always worked and it's the only Audi I've ever owned that didn't have a single electrical gremlin besides maybe the climate control bulbs finally burning out but that wasn't a glitch just age catching up with it. The Webasto was also excellent, made it much less stressful leaving it for long periods of time out in -40 with no access to electricity to boost or plug it in (I didn't have a block heater anyway). Once again if I did it over I wouldn't wire the Webasto directly to the HVAC system like I did though... the way it was configured it would activate the HVAC only when the coolant was warm enough but by default this makes the blower run full blast until the car gets up to temp. The blower draws much more power than optimal and if left too long will make the car unable to start. I would have to make a mental note to override the blower speed before shutting off the car. If you just used resistors and a bypass relay like Webasto recommends (which I thought was ugly and inefficient compared to the PWM blower controller the Audi has) this is much less of an issue, though there is a chance the relay could render the blower non functional if it failed. I have a spare HVAC assembly, I could grab another PWM and build a constant low speed controller to just run the fan maybe instead of resistors next time... Depends on how much room is in the next vehicle, the Webasto may not even be practical, we'll see.
I hope everyone has been doing well! Sorry for my absence!
Dave