timing chain(belt?) issues?

[s4shzl]

i have a B5 S4 and don't know too much about the B6 S4, but my buddy wants to pick one up. a bmw m3 owner mentioned that the B6 S4 has some timing chain(or is it belt?) problem and that the motor had to be pulled at like 50k to replace it or fix it or whatever... can anyone shed more light on this or anything related? thx

[H0LLYW00D]

The 4.2 found in b6/b7 s4's uses a timing chain that has to be replaced at 100k. The older b5 2.8tt motor uses belts that have to be done rought every 50-60k if i'm not mistaken. Both motors have to be pulled to replace these parts.

[ngng]

The 4.2 found in b6/b7 s4's uses a timing chain that has to be replaced at 100k. The older b5 2.8tt motor uses belts that have to be done rought every 50-60k if i'm not mistaken. Both motors have to be pulled to replace these parts.

umm...

[Jdubya]

Pulled? The last time I watched a timing belt get done the front end of the car was taken off. No motor pull needed.

[ChronicTeutonic]

The 4.2 found in b6/b7 s4's uses a timing chain that has to be replaced at 100k. The older b5 2.8tt motor uses belts that have to be done rought every 50-60k if i'm not mistaken. Both motors have to be pulled to replace these parts.

Yes there is a timing chain, and it's at the back of the engine but I don't see and 100k replacement service in the Bentley Manual Maintenance Schedule. Did I miss something???

OK, I'm calling bull$hit on this one...

Found this in the Audi Training Guide on the 4.2 FSI engine:

"Correct chain tension is ensured by hydraulic tensioners. The chain drive is maintenance-free and designed for lifetime service."

[s4shzl]

ya most chains usually last a lifetime.. u dont have to pull the motor to do a belt job on the b5. so theres no common issue or anythin like that with the b6 chain? everything is straight?

[ChronicTeutonic]

ya most chains usually last a lifetime.. u dont have to pull the motor to do a belt job on the b5. so theres no common issue or anythin like that with the b6 chain? everything is straight?

straight as your hooter....

[ngng]

Yes there is a timing chain, and it's at the back of the engine but I don't see and 100k replacement service in the Bentley Manual Maintenance Schedule. Did I miss something???

OK, I'm calling bull$hit on this one...

Found this in the Audi Training Guide on the 4.2 FSI engine:

Audi also states 10k miles for an oil change, and lifetime tranny fluid (for the C5 A6)

[colonelburke]

He may have been confused and was thinking of the chain tensioners that usually need to be replaced at some point, but that is not a maintenance thing, and I do not beleive there is any set schedule as you replace after they go out. Big job, motor out to do, again IIRC.

[Jdubya]

Chains are a lifetime, it's the plastic tensioners that aren't.

[ngng]

Chains are a lifetime, it's the plastic tensioners that aren't.

what's the suggested replacement interval on those?

[s4shzl]

just so ur aware i doubt its plastic tensioners lol.. should be hydraulic tensioners in that thing, i think ur referring to the plastic guides

[ChronicTeutonic]

Most of the cars that I've had to rebuild needed something other than a chain tension guide long before I needed to worry about replacing it. We're talking about stuff from the '60s and '70s, so I'd guess materials engineering has become somewhat more advanced by now...

Is this horse dead yet?

[H0LLYW00D]

I was wrong about the b5, sorry, thanks for correcting me.

Timing chain and tensioners 100k, i've heard this multiple times from techs for b6/b7's. You don't actually need to swap the chain if it's in good shape, but everyone does it anyways if the motor is pulled.

[ChronicTeutonic]

which one?

[Lugi20]

^^^

I have a ford 4.6L DOHC and when it comes to working on that thing I have balls of steel. Looking at that pick made me feel like my steel balls just dropped.

[AudiOso]

So every S4 that hits 100k is allegedly supposed to have its engine pulled? Bee Ess

[Jdubya]

^^^

I have a ford 4.6L DOHC and when it comes to working on that thing I have balls of steel. Looking at that pick made me feel like my steel balls just dropped.

Not that they are THAT much easier to work on. My Cobra 4.6:



The timing chain service for the VW's is supposed to be around 100K but I've pulled a lot of VR6's apart past 150K and the chains/guides looked fine, but then again I've seen them break at 70K also.