reliability of the allroad? or 2.7T

[Chris Newbold]

On 5/1/07, Grant Lenahan <glenahan at vfemail.net> wrote:

> the 2.7 is tremendously tough.  The K03s are delicate, but fine, if you
> use the right oil (M1 0W40, ELF Excellium 5W40, etc), take it easy on
> warm-up, and cool them Down. Trouble is, did the PO do that?

> The Allroad had far fewer failures than the S4s too. Why? Not sure. Two
> ideas:  1) much more engine compartment room, hence lower heat.  2)
> less drag strip kids with chips beating the &*%St out of them. My S4
> ('00) was quiet as a mouse at 80k, when I sold it.

I'll add my own data points and opinions. I have both a 2001 S4 and a
2004 allroad 2.7T-- same motor in both of them. When I got the S4,
there was a fair reputation for blown turbos. I mostly dismissed it as
1) spanker kids chipping the heck out of it; 2) lack of proper warm-up
and cool-down; and 3) rumored turbo oiling problems in the early 1999
and 2000 MY motors.

So for 50k miles, I carefully warmed up with light throttle until the
oil temp was around 200deg.; always cooled-down until the oil temp
returned to around 200deg; used high-quality synthetic oil; and left
the motor entirely stock. I did flog it hard, but responsibly so, I
thought.  Then around 50k miles, it started blowing blue smoke on
startup. Uh oh. The dealer diagnosed immanent turbo bearing failure
and replaced both (thankfully under the Audi extended warranty).

At this point my opinion is that they've got a heat problem in the S4.
 High heat == severely reduced bearing life; the K03 turbos are not
ball-bearing. Chipped cars fail faster and more often, as more boost
== more heat == more stress. We'll see if the replacement turbos fair
any better, but I'm thinking it'll be time to dump the S4 (though I
dearly love it) around 100k miles before I have to pay for another set
myself.

Back to the allroad. I've found the allroad runs oil temps. 15-25deg
less than the S4 under similar operating conditions and the oil temp
does not spike under heavy use the way it does in the S4. I don't have
to work all that hard to get the S4's oil temp close to 250deg (and
I've seen 275-300deg on the track). I've never tracked the allroad,
but I've never, ever seen the oil temp rise much above 225deg even
when I hammer it hard on the street. There's vastly more space in the
engine compartment on the allroad, and I cannot help but think that
the extra air circulation helps to keep turbo temps in check.

My only serious concern about the allroad is the air suspension. Lots
of annecdotal evidence of leaks in the air struts, compressor
failures, etc. I've already had the front struts replaced under
warranty due to a leak. Like turbos on the S4, this is not something I
ever want to get stuck paying for.

-Chris
2001.5 S4 Avant 6spd
2004 allroad 2.7T