Everywhere I look, I read that the 2004 S4 has a timing chain and that it doesn't need to be replaced.

However, my maintenance manual lists the timing belt replacement as a service item for the 125,000 km service. The engine in the car is the 4.2L V8.

I am confused...

Any idea what exactly needs to be done and how much it'll approximately cost at an Audi dealer?

 

Mystery solved... it does have a timing chain. So I guess the maintenance manual is wrong. Thank god I don't have to pay for a timing belt replacement... still an expensive service at 125k km though.

 

It is rare to have to replace the Timing Chains on a 2004+ 4.2L but it is not out of the question. Recently came across a 2004 S4 at ~185K KM that needs new chains / guides / tensioners / hydraulic cam adjusters / replace clutch while engine is out / etc. Again, this is rare so stay on top of regular maintenance including quality synthetic oil changes and most will be fine.