2006 Audi S6 C6 V10 build

[gs_audi]

Hi, I’m gonna make a thread here for anyone interested. I bought a 2006 Audi S6 V10 with 73k miles. In a bit of a rough shape maintenance wise, but I saw some potential in it, and it has reasonable miles.

Timeline:

• I bought the car 12/2022

• Scanned VCDS

  • Motor mounts short to ground
  • Cat on bank 3 low efficiency

• Oil leaks

• Coolant leaks

• took the car to the shop 3/2023

• fixed some oil leaks, still leaks onto the manifold

• eventually coolant leak came back mysteriously

• oil leak on manifold became so bad I feared the damn thing will catch fire any minute

• had it towed to the shop AGAIN 7/2023

• told them to actually fix it now, cost be damned

Our situation now at 1/2024

• changed a lot of parts, new motor mounts, head gaskets, spark plug tube gaskets, cam girdle reseal, new alt, starter, steering wheel pump, you name it
• car still at shop
• the guys telling me it’s still leaking oil
  • I did some googling myself and brought them some new VVT solenoids, prolly got it now (f*ing hope)
• can’t get it to run properly, misfiring on cyls 7 and 8
  • new sparks, new coils, I guess I gotta start looking at some new injectors now

Damn. But I’m still hopeful we gonna get it to run eventually.

My plan is to restore the car to 100% stock, tho it has a map for 465hp. Gonna get it as technically sound as possible, maybe install it to “fully loaded” state, and maybe give it MMI3+. Gonna post some pics if you guys want

Cheers

[gs_audi]

Here’s the beast pictured from last summer

[gs_audi]

In the cold snow. Rear lights look like ass, got some replacements for the inner tail lights, just gotta fit em

[desertrock]

Congrats. How were the motor mounts to replace? Engine out? Mine are also shot.

Cat efficiency for me is related to an exhaust leak after the cat (broken bolt). Check it if you haven’t already.

Apparently it’s another typical fault for the oil to leak from a gasket near the oil filter housing. Can’t remember exactly, but mine was leaking there and it was a simple fix that was done while carbon cleaning so the intake manifold was off.

[justincredible]

These cars still look great today. They age really well. great pix.

[gs_audi]

On the 4.2 you can kinda replace them without engine out… Can’t say about the 5.2… The engine was out when they were done.

Gotta see about the exhaust. I’m sure the inspection (katsastus) dude will see it if I can’t

Yeah I changed both oil filter housing O-rings…

[desertrock]

If the leak is small enough they won’t necessarily as two of the cats are way up inside the engine and difficult to see from under. Mine passed emissions by just clearing the codes before the inspection. It was only noticed by the exhaust guy who made my cat-back exhaust. When air gets into the exhaust, the post-cat O2 sensor can be fooled into thinking the cat efficiency is lacking.

[Dlugi11]

You can replace motor mounts in car no problem.

[gs_audi]

Update:

Got it back from the shop, the shop guys threw in the towel, they don’t want it anymore. Lmao

They said it idles pretty rough, and don’t know why. “But here’s your car back, sir.” At least they didn’t charge me too much labor.

So basically my leaky car that was running perfect, is now a leaky car that runs like crap.

Next step is to fix it myself I guess, I’m starting to get the picture that these special cars are just beyond repairing for 95% of mechanics, you gotta learn it yourself and do everything.

I had the car towed to a secluded lot, and I will take my loaner with some jumper cables and see how bad it runs. I haven’t heard it run after the botchery. I will post some clips

[desertrock]

You just have to find a shop that know what they’re doing. There’s a few in my area that I could recommend, but obviously you live up north so… By the way I just realized how low mileage your car is! That’s sick. Too bad it’s in such a rough shape internally it seems. The injectors do get clogged and also leaky, I had to have every single one replaced as they were all over the place and beyond saving.

[gs_audi]

The dang bonnet opener wire just came off lol, got the bonnet open with great effort. Now gotta check why the wire came out

[gs_audi]

Went and gave the car a whirl, starts up almost normal, then immediately goes into violent all cylinders misfire, stalls immediately. If I jam the gas up half way when starting, it revs seemingly fine above 3000rpm and stays running, but as soon as I let go of the gas, it stalls. Damn. VCDS giving misfires everywhere. Gonna keep you guys posted once I get the VCDS report.

[gs_audi]

New tech called me. Said he got it running, took it for a spin. Also no more smoke!!! The VVT solenoids caused the oil smoke all along. #hopeful

[justincredible]

Great follow up. What codes popped up for this if any?

[gs_audi]

Guys! The specialist dude called me up, told me to come to the shop. The car runs now. I took it for a spin. Pulls good. Idles smooooth. Gonna try for a roadworthiness inspection tomorrow. I might actually drive my damn audi on the road after like 9 months.

Now as for what was wrong: vacuum leaks. Two in fact; throttle body was literally dangling on the Y-plenum. The Y-plenum and the intake manifold were missing the dang seal, meaning it was seated at an angle --> leaks a bunch.

Wish me luck for the inspection!

[gs_audi]

Also no smoke. It was the VVT solenoids all along.

[justincredible]

Did you get an error code for the VVT solenoids

[gs_audi]

No, just some extreme smoke from the engine…

[gs_audi]

Car passed the inspection without any complaints. 40mins after the inspection I get the “adaptive light defective” lol. Hopefully I can just use VCDS to get it out and figure the light “defectiveness” out later.

On to the next; there is a maaajor oil leak still at the front of the engine, shop #1 said it’s the engine oil cooler. I wouldn’t be surprised if they just put the new cooler on, with the old O-rings. The cooler was probably fine all along, why would it not be.

Back to the garage soon. But at least it’s inspected for the road now.

[audis6]

O-rings on front oil cooler from my car, hard plastic and cracked inside,