Racingsnake
Racingsnake Reader
4/12/24 6:09 p.m.

How scared should I be of buying one of these? I know the timing chains are at the back of the engine so doing chain guides is likely to be a hassle but what else should I know?

rdcyclist
rdcyclist HalfDork
4/12/24 7:09 p.m.

In reply to Racingsnake :

You just answered your own question. The B6S4 V8 timing chain system is an incredible PIA to change out. Plan on about 4-5 grand in parts (it's gonna be more than just the timing chains, guides and tensioners, there's hoses and all sorts of other E36 M3) and lotsa hours. Even if they've been changed, the quality of the work done now becomes the issue.

There's a reason changing out the entire V8 for the 2.7tt V6 from the B5S4 is a thing.

Here's a picture of what we're talkin' 'bout:

RonnieFnD
RonnieFnD HalfDork
4/12/24 7:15 p.m.
rdcyclist said:

In reply to Racingsnake :

You just answered your own question. The B6S4 V8 timing chain system is an incredible PIA to change out. Plan on about 4-5 grand in parts (it's gonna be more than just the timing chains, guides and tensioners, there's hoses and all sorts of other E36 M3) and lotsa hours. Even if they've been changed, the quality of the work done now becomes the issue.

There's a reason changing out the entire V8 for the 2.7tt V6 from the B5S4 is a thing.

Here's a picture of what we're talkin' 'bout:

Well put.  I work at a Audi dealer and we all love em but nobody owns one lol.  Most dudes play with S4s but nobody seems to hang on to the v8 cars.  That aside they are freaking awesome. 

pointofdeparture
pointofdeparture UltimaDork
4/12/24 7:37 p.m.

They are pretty cool but AFAIK it's not just that the chains/guides/tensioners/adjusters are a nightmare to change, they also have the wonderful trait of "some blow up at 50k and if you're lucky they will hold out and blow up around 100k". Even if you do it yourself the job sucks ass and the parts are thousands of dollars while if you farm it out to a shop the ballpark is likely gonna be $8000-10000.

I once read on a different forum that some guys just buy a lower mile engine for $3000 and swap it every time the timing chains go because the service is that much of a pain. That right there is hilarious to me.

Racingsnake
Racingsnake Reader
4/12/24 10:36 p.m.

Yeah, that doesn't look like a whole lot of fun to deal with... 

Any warning signs before they let go? I'd assume they get a bit rattle first? 
 

Shame they're problematic because they're nice looking cars and seem like they'd be be good fun

codrus (Forum Supporter)
codrus (Forum Supporter) PowerDork
4/13/24 12:39 a.m.

Everyone on the Internet loves to hate the Audi 4.2 V8.

Yes, they do rattle before they blow.  50K sounds very low to me, I'm sure there are a few that have blown up at that point but it's certainly not common.  And a good chunk of the price is "while you're in theres".  Yes, those probably make sense if you're paying someone to do all of the labor, but if you're doing it yourself then maybe/maybe not.

They are really fun engines, they love to rev and make glorious noises.

 

DrMikeCSI
DrMikeCSI Reader
4/13/24 7:20 a.m.

Holy hell that looks insane. 

Racingsnake
Racingsnake Reader
4/13/24 10:26 a.m.

What is the likely life expectancy before they need chains/guides? At around 100k have they probably been done already or are they likely about to go?

P3PPY
P3PPY SuperDork
4/13/24 10:49 a.m.

There's another thread on here about a particular V8 S4. It's sometimes pertinent to you, maybe have a gander

https://grassrootsmotorsports.com/forum/grm/advice-for-neighbor-on-audi-s4-purchase/257942/page2/#post3896661

docwyte
docwyte UltimaDork
4/13/24 10:49 a.m.

No!  Not only do they have issues with the timing chains/guides, but they also have issues with cylinder wall bore scoring, cam deviation issues, etc, etc.  Both of those last ones are unfixable.  They tend to eat oil, then one day, eat a LOT of oil, then you're looking for another bottom end.  Which will also be used and have the same problems.  On top of that they get gas guzzler mpg's, far worse than a 4 liter should get.

NOHOME
NOHOME MegaDork
4/13/24 11:59 a.m.

In my opinion: Example of poor engineering.

Same design philosophy as a Rube Goldberg device

 

 

pointofdeparture
pointofdeparture UltimaDork
4/13/24 12:51 p.m.

In reply to NOHOME :

VAG should win some kind of award for its 30+ year streak of timing chain design incompetence. From the early VR6s to the class action lawsuit letter I recently received for my (long sold) 2016 GTI, it seems like they are fundamentally incapable of saying "alright guys, we gotta do this one right."

Most other companies seem to do a better job, at a bare minimum they could make them last longer OR easier to service, being unable to do either is just some kind of cruel joke.

CyberEric
CyberEric SuperDork
4/13/24 12:53 p.m.

Wtf were those engineers smoking?

Floating Doc (Forum Supporter)
Floating Doc (Forum Supporter) UltimaDork
4/13/24 1:00 p.m.

Funny seeing this today. I followed one on the way home yesterday, smoked a LOT when decelerating. 

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