[s-cars] S4 sighting

[Taka Mizutani]

D2 A8s are fine- they have a timing belt. But the rear timing belt Audi
4.2s have a problem with the chain guides failing (brittle plastic) and
then the chain guides break off, losing chain tension which subsequently
causes a loss of timing. The guys on the list running Audi V8s, UrS and
even the D2 S8s don't know how good they have it. :-)

The same issue afflicts MBZ V8s- at least the W211 E500s and other cars of
the same vintage (ML 500, S500, etc.). Same thing with E39 BMW V8s. But
what I was saying was that at least BMW and Benz put the chain in the
front, so you merely have to take off the front bumper, ac condenser,
radiator, fan, all the belts off the front of the engine, then the valve
covers and intake manifold (that part is ridiculous), then you have access
to it. Unlike the Audi where you have to remove the engine and
transmission, separate the two, do the chain guides on an engine stand,
then put it all back together. The difference in labor is at least triple
if not four times the job of the E39.

I don't know enough about the Valvetronic V8 in the later BMWs (E60, E65,
E63, etc.) or the Benz E550 engine to say that the problem still exists.
The timing chain problem has been a longstanding issue, present in W126
S-Classes as well and probably in your W124 500E, Mike. Make sure you don't
have a rattle on cold start up.

Engines running full synth their whole lives are pretty clean- I just saw a
few S54s opened up with 70 and 80k miles with a light varnish, nothing
else. Relatively clean and looking to go another 100k. The RS4 issue is a
by-product of direct injection- a lot of DI engines have a similar carbon
buildup issue. I wonder if adding water injection into the intake manifold
would help that.

BTW, what's the issue with the later MLs? I thought that they were
generally well-made trucks- I know the interior is very much about hard
plastic, but otherwise.....


Taka



On Fri, Dec 30, 2011 at 8:54 AM, Michael Lardizabal <
mikellardizabal at yahoo.com> wrote:

> Taka haiku'd .....
>
>
>
> > I wouldn't put one of those V8 atrocities on anyone- no thanks. I think
> the Germans have forgotten how to build a V8 properly- the MBZ V8s and the
> BMW V8s have similar chain guide problems, although their problems are at
> the front of the engine, where it is merely a 8-10 hr. job rather than the
> stupidly ridiculous job it is to fix on the rear timing chain Audi V8.
> >
>
> I honestly feel that the Germans are building very powerful and efficient
> V8's > especially if you take into account hp/liter .....its just that they
> now ( at least since 03..IMHO ) diligently design-in " planned obsolescence
> " .
>
> Our 2010 Mercedes ML350 is a technological marvel for an SUV....its got
> barely 30K on it, I really don't see this truck running well past 100K .
>
> On the other hand..my old Mercedes 500e and my previous AMG C
> class......now those cars will go into the 500K range w/o ever opening up
> the motors. Where's the money in that ?
>
> I say since 2003 because just last week I saw up close a 4.2 from an 01 A8
> that skipped a belt. Pistons and cylinder walls + chain drive looked like
> the day they left Ingolstadt !
>
> Twas really quite a sight to see how little to no wear 120K had on this
> motor. The valves looked like ass, but nothing that would deter it from
> going another 40-50K w/o flinching...and no where near as slime-sludged  as
> the pics the B7 Rs4 guys post up on a regular basis. The A8's gunk was more
> old-skewl hard build up.
>
> Pre- FSI splendor.
>
> Mike L
>
> --- On *Fri, 12/30/11, Cody Forbes <cody at 5000tq.com>* wrote:
>
>
> From: Cody Forbes <cody at 5000tq.com>
> Subject: Re: [s-cars] S4 sighting
> To: "Taka Mizutani" <t44tqtro at gmail.com>
> Cc: "Tom Heitzman" <gyro at stuffinder.com>, "s-car-list-bounces at audifans.com"
> <s-car-list-bounces at audifans.com>, "Robert Myers" <bob at chips-ur-s.com>, "
> s-car-list at audifans.com" <s-car-list at audifans.com>
> Date: Friday, December 30, 2011, 1:42 AM
>
> AFAIK all VAG engines with a timing chain put it on the back of the engine
> even going back to the older VR6's.
>
> What's wrong with the S5 V8? It's not the same as the troublesome B6 S4
> V8, the FSi V8's are a clean sheet design and as far as I've seen are as
> reliable as any other VAG engine.
>
> -Cody (mobile)
>
> On Dec 29, 2011, at 6:25 PM, Taka Mizutani <t44tqtro at gmail.com<http://mc/compose?to=t44tqtro@gmail.com>>
> wrote:
>
> > I haven't driven the S4 with the 3L supercharged, but the A7 with the
> 3.0T was quite a nice setup. I imagine a more performance-oriented setup
> would be even better.
> >
> > I wouldn't put one of those V8 atrocities on anyone- no thanks. I think
> the Germans have forgotten how to build a V8 properly- the MBZ V8s and the
> BMW V8s have similar chain guide problems, although their problems are at
> the front of the engine, where it is merely a 8-10 hr. job rather than the
> stupidly ridiculous job it is to fix on the rear timing chain Audi V8.
> >
> > Cody- is the V6 supercharged a conventional timing chain setup?
> >
> >
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