m444

Others have noticed the air to coolant charge intercooler tends to stop the debree from entering the engine.

dwboston

Is there something radically different about the S6 vs. A8 engine placement/design for the 4.0T? I don't believe the front end of my NWB A8 needed to be disassembled for the turbo replacement, but maybe it did and it just wasn't noted as part of the repair procedure.

m444

The A8 is a bigger car than the S6, with more room at the front. Yes it'seasier to change the turbo oil supply screen on the A8 body (do not need to to remove the bumper cover).

dwboston

Agreed in general, but the short wheelbase A8 isn't that much bigger than the S6 (from the specs I could find it looks like the NWB A8 is 8 inches longer than the S6). I had a 2012 A6 Prestige right before the 2015 A8. When I got the A8 I expected it would feel a lot bigger and you'd think the trunk would be significantly bigger....but it's not.

MP4.2+6.0

A8 is wider in general. Width of engine bay has to be scaled to widest motor, which is W12 and not found in C body. Front clip probably longer too--has to do with whatever the longest engine is they ever intend to stuff into it, plus styling. No more V10 in either, which I think was the old longest one. Both have to house the 4.0T; some diesels may be biggest ones now. Out of sight, but D bodies also scale probably for the "Armoured" modified versions for Merkel and the various sheikh buyers.

D4 trunk designer was re-assigned to the Siberian facility for fifteen years to check cold weather sealing of Audi trunks--from inside! Even with the facelift, they could only lipstick the D4. The "seem'ed like a good idea at the time" was to sandwich a bunch of electronics between the back seat bulkhead and the inside of trunk. D bodies have to have that bulkhead to tame aluminum flex, while C bodies are all typically available as wagons in Europe and allow both fold down seats--and where exactly they put that seat division sans bulkhead let alone a two layer space. Another subtle space waster on D body is the fuel filler--where whether gas or TDI they left room for the AdBlue filler tube--look at it and notice extra blank area. I think that also had to do with trunk depth and gas tank size down relative to D3 and then pre- and post-facelift difference.

LimeyBoy

I'm guessing turbo fail issues are 99% of the time oil related - so bearing or journal, both would fail if oil pressure and flow dropped below required...?

HBA8

So im a little confused. The silly rabbit package includes the OEM Audi check valves and oil screens. Is there a less restrictive oil screen and a better check valve? I want to douvle check before i do this work....i only want to do it once. Thanks all!!

m444

That would be news, if there were. The latest revision of OEM screen and check are the best known options, as noted in the revision 4 of turbo fail TSB for 4.0t.

HBA8

i checked the screen in the box and it’s the latest “G” version so I think I’m good! In all the parts I got, im not sure I’ve seen a check valve yet. Anyone know what it looks like or have a part #?

thanks in advance all!!

spdemon91

Check valve 079103175C...