2003 S6 - Beginning the Repairs and I've got Questions

[cord4530]

I ended up buying khalimadeath's old S6 (it's changed a few hands, but it is in mine now). As a quick description of the car, it is a 2003 S6, and has the 6-spd manual swap, along with ST coilovers, 034 UCA's, Porsche calipers with 2Bennett rotors, and lots of other goodies installed.



I'm starting to uncover some of the issues, and beginning to fix them. But there are a few I would love to get some input/ideas from forum members.

1. When accelerating in 1st gear, the center driveshaft makes a clunky/vibrating noise. I had this in a previous Audi, and it was the transmission mounts. Is there any consensus about which transmission mounts are used with the 6MT swap? The parts list says to use the mounts from the transmission donor, but other threads say to use the original mounts from the S6 tiptronic.
2. Are there other things I should be looking at for this clunking/vibration? Is the center support bearing a common failure? Or the CV joints on either end of the driveshaft?
3. I'm also suspicious of the mounts because when getting on/off the throttle (gently), there can be a bit of an oscillation. This would lead me to believe the motor/trans is moving around more than it should. I got about 3/8" of movement on each mount when I used a jack to lift each side of the transmission.
4. I didn't detect any motion on the engine mounts. Don't these mounts have sensors in them that would indicate when they have gone bad?

I'm sure there will be more things as well, but the vibration is my initial concern. It seems to be losing a little bit of coolant over time, but I haven't noticed any leaks on the right side (oil cooler pipe). I need to check the reservoir for cracks. I also have a small hydraulic fluid leak, but it appears to be coming from the reservoir or hose from the reservoir. I'll be cleaning/inspecting that soon too.

Thanks for any tips/information you can share about the vibration.
-Dan

[mithril]

I believe most use RS4 transmission mounts, but I'll defer to the guys who have actually done the swap. I'll sure rollerton will chime in soon.

[rollerton]

wheeeee!
I used all the OEM tip mounts (assume we're just talking about trans mounts) that were in my S6 when I did the swap. I didn't notice any reason to swap them, everything lines up pretty much. I guess there's a version- Rs4 or Auto A6?- that is about 3/8" thicker than the stock 4.2 mount..if I remember right. I don't see the benefit of them, but they might add 60 hp.
Everything lines up Except the downpipe supports, which I still haven't bothered with. Haven't noticed an issue with that though. Probably something I should do someday.

I hate clunking, I don't know how you go about diagnosing that for less than your life savings. I feel like if it's clunking sort of dynamically, while in motion then maybe driveshaft? IF it's during clutch action then maybe a worn subframe mount/ bushing or lower control arm? I've read that the subframe can develop cracks that cause a CLAK or CLUNK sound when they flex. Who was it...Mithril ? Somebody had that problem.
As far as the driveshaft, my opinion is that the center hanger and U-joint is super durable and is less likely to cause an issue than the ends. And would cause vibration either always or more under changing/heavy load situations, like accelerating at low RPM.

[Kruat]

I was eyeing that car for awhile...wish I had the room in my garage.

[mr_dave]

I can't help with the clunking, just wanted to say nice looking S6! And awesome color! (I have the same)

[A Stupid Turtle]

Not to de rail... can you disclose how much said vehicle was or ball park?

[cord4530]

Thanks for the warm welcome!!!

rollerton, I've read so many of your posts. You're an icon of the 01e swap. Thanks for the info on which mounts you used. I'll get another set of those ordered up. Now...to decide on stock-style mounts, or the 034 Motorsports mounts...

Kruat...this car was in your back yard! And it changed hands twice in about 3 months over there. I haven't been able to find out anything about the 4th owner, other than he traded the S6 for a Subaru with the PO.

mr_dave, you have fine taste :o) Looking up the color code (LY5X Aqua Blue Pearl/Aquablau Metallic), it seems this was available only on the C5 S6. I think it's gorgeous.

Turtle, I paid $15k for the car. I had a hard time finding pricing to compare. But in the NW there were two other C5 S6's with similar miles on them for $12-13k, and they still had the original tiptronic transmissions. Considering the work that khalimadeth did on the car, I figured that wasn't a bad deal at all. I could be way off....

More on the noise:
A clunk is probably not the right way to describe it. It certainly sounds driveshaft-related. It's not like it just makes a single clunk. It would keep thumping at around driveshaft frequency so long as you're accelerating hard in 1st gear. But I wouldn't call it a vibration either. When accelerating modestly, or cruising there is no vibration at all. And even full throttle in 2nd gear or higher produces no noise/vibration at all.

Many years ago I had a 1991 200 CSTQ sedan. It did nearly exactly the same thing. I played around with aligning the center driveshaft with no success. But eventually found the transmission mounts were shot, so much that under acceleration they changed the angle of the transmission enough to cause the CV joints to make a ton of noise. After replacing the mounts the problem was completely gone. I was hoping this was similar, or possibly the differential mounts (which I haven't inspected yet).

Anyway, many thanks for the replies and tips. My hope is to fix this car back up to its original glory and keep it for a long time. However, my fiance is horrified that I bought a 4dr wagon. :o)
-Dan

[Fast Co]

Like many here, I have also had several Audis over the years including a '95.5 S6 Avant, '91 200q20v Avant, '90 CQ, a couple of 5000 TQAs, and the obligatory 4000S quattro. In 2014 I bought a 2002 S6 and like it so much that I really want to add a manual version to the stable.

I too was very interested in this car. Had a few conversations with Tanner (the seller) who as Dan noted, is not an Audi guy. He told me that he acquired it in trade for a Subaru with the intention of reselling (flipping). Had it on ebay a couple of times. I had a friend from Seattle test drive it. Knowing that Dan was also interested I decided to pass. Taking into consideration the cost of shipping across the country then 'fettling' to get it right, I figured I'd have at least $20K into it. It is a lovely car, beautiful color and proper mods. Dan, I wish you well and hope to follow your updates.

I do have something else up my sleeve, don't want to threadjack.

[A Stupid Turtle]

Only asked to have a comparison for mine (on rebuilt tip trans) lol...

[cord4530]

Andy!! You were the buyer ahead of me. So happy we've met on AZ.

My Audi ownership list isn't as nice as yours. My first was a 1987 5000 CSTQ, followed by the 1991 200q20v. Then I had a few years without an Audi, but in 2012 I got a 2007 S6. I gave that to my ex when we split up, and immediately started shopping for its replacement. I've always lusted after an avant. I considered a B7 S4 with the manual trans, but don't like the direct-injection engines much. My C6 just barely turned 50k miles, and was already showing signs of carbon buildup. Two friends have allroads with the 2.7T, and one has the manual transmission. But I really love the S cars. When I saw this one come up, and that it has the manual swap it was the first car that I had gotten excited about since shopping.

I thought for sure you were going to buy the car, and I thank you greatly for leaving it for me. That's super cool that you've got another idea up the sleeve. I can't wait to hear about it.

For updates, here is a quick list of things I'm looking at. Most of the things are pretty small, but I'm just going to whittle away at it. And I'm sure unexpected jobs will show up (oil cooler coolant pipe?):

• Figure out and fix noise/vibration under acceleration
• Find an owners manual for the car (anyone have one, or PDF?)
• Raise the suspension slightly
• Make hanger for front brake lines (to keep them away from the CV shafts)
• Replace both front outer CV boots (starting to leak)
• New coolant expansion tank (small crack)
• Get a second key/fob and program it to the car
• Update stereo system
• Find/fix small power steering leak (looks to be reservoir or low-pressure hose)
• Replace or repaint climate control unit
• Replace a few plastic trim pieces
• Remove the rear hatch screen/divider
• Order a set of winter wheels/tires for next season
• Should be due for the timing belt job in around 15k miles

Then there are all the cosmetic things to address:

• Front and rear bumpers could use a respray, and might buy a new bumper for the front
• Will probably replace the euro tub with a USDM tub
• The rear hatch interior panel isn't attached well. I will probably need to source another, since tabs are likely broken

[Fast Co]

I was "this close" to pulling the trigger. If you weren't there waiting in the wings, I probably would have bought it. I even had non-buyer's remorse for a while but I figured something else would come along.

[mr_dave]

Turtle, I paid $15k for the car. I had a hard time finding pricing to compare. But in the NW there were two other C5 S6's with similar miles on them for $12-13k, and they still had the original tiptronic transmissions. Considering the work that khalimadeth did on the car, I figured that wasn't a bad deal at all. I could be way off....

Not off at all. I paid about 3k more for mine last year, but it only had 47k miles on it at the time and was 100% stock. Pricing is all over the map for C5 S6s but the nice ones seem to hold their value surprisingly well, probably because you simply cannot get anything else like it in terms of size, quality, and capability.

Since then I've done a fair amount of maintenance (full TB, seals, BND trans fluid, etc.) and I just recently replaced the tired original dampers (with Koni FSD), rubber suspension components, and upper control arms. After getting a full alignment - WOW, I am extremely impressed with how nice this car feels. Even after 13 years, it looks and drives like it's brand new! It's just so... solid, and eager, and comfortable.

[bpark1210]

I saw your S6 on the Seattle Craigslist when I was searching for my wagon. It's got a nice list of upgrades but I couldn't justify the price for myself. It's a great pick up for such a rare and well maintained S6, congrats.

As for your list of maintenance items they all sound too familiar to me. That's all expected w/ these 10+ year old cars. I can advise you on one item I came across via rollerton's post for your rear hatch warning triangle cover.

Nice guy is printing them:
http://www.thingiverse.com/thing:12550

Order here:
http://www.shapeways.com/model/10354...ml?li=shortUrl

I came across that post after I ended up buying the entire cover assembly via ECS on sale for $25 but you should be able to just pop in a new plastic latch piece for a lot less or even print your own if you have a 3D printer.

[cord4530]

Thanks for the tip on the hazard latch. On this car, the whole lower panel on the hatch is somewhat loose. I just pulled it off this morning, and one of the PO's definitely did not read the manual about where the clips/fasteners were. The carpeted section is completely separated from the upper plastic piece. And about half of the brackets holding it to the hatch are also broken. I'm sure it could be repaired, but I'm thinking a replacement would be a better idea at this point. Additionally the clips that the hazard panel pivots on are also mostly broken as well. I just ordered a new tailgate lower trim panel, part number: 4B9 867 979 F LCQ

While in there, I figured now was a good time to install a USDM licence plate tub, so I've got one of those on order as well. Both are scheduled to arrive around February 1st.

It's interesting that so many of the tabs were broken on the hatch trim. I've had the door panels off, and all of those were still in fantastic shape.
-Dan

[JBX]

I really like your S6. I had been looking for a swapped S6 for quite a few years and when I finally pulled the trigger what became your S6 popped up a few months later. :) I paid about the same for my S6 but although it has fewer miles it doesn't have the brake upgrades or the fantastic color yours has. Anyway, I too have to pull off the rear hatch piece to retrieve the broken latch piece from the hazard cover that is rattling around in there (I replaced it with a shapeways printed one--thanks to this forum) and while I am in there, I will hook up the other rear foglight and probably dynamat/brownbread what I can. I am guessing you have seen this disassembly vid but if you haven't here it is (maybe your panel can be repaired?):

https://www.youtube.com/watch?v=TxE5O6L42Os


Also, I rarely buy things based on others opinions but after reading a lot about Hotchkis sway bars on this and other forums, I picked up a set and am happy I did. It is not night and day but very, very good. Look into it if the car is on stock sway bars.

Take care.

--jb

[rollerton]

I don't know what they were thinking with the little rear hatch door thing. It's stupid and it's a stupid design. I considered how much actually USE that particular little thing...then I just put a fuckin' screw right through it to keep it shut. It's a small black screw, tiny little hole, so aesthetically it's not even noticeable. And the door stays shut. The little stupid door gets ruined when it flops open too many times then gets caught and yanked on, so for now...mine will be closed and remain unbroken!

[S6XTC]

I don't know what they were thinking with the little rear hatch door thing. It's stupid and it's a stupid design. I considered how much actually USE that particular little thing...then I just put a fuckin' screw right through it to keep it shut. It's a small black screw, tiny little hole, so aesthetically it's not even noticeable. And the door stays shut. The little stupid door gets ruined when it flops open too many times then gets caught and yanked on, so for now...mine will be closed and remain unbroken!

Amen....

[cord4530]

Well....my plan is already foiled. I had located a great deal on a new rear hatch interior trim panel. But like most good deals....this one evaporated after I ordered it. So, I'll either be looking for an alternative (still available from OEM for ~$600 after shipping), or possibly repairing mine. I've got some decent ideas for connecting the lower carpeted section to the upper plastic section. But I'll have to give some thoughts to how to attach the hinge for the emergency triangle (since most of my clips are broken). Strangely enough, the latch for my little hatch door is still in okay condition.

Or I can keep searching the classifieds for a good used panel. I just suspect that most have broken tabs and things, and wouldn't be a much better starting point than my current set.
-Dan