Does the 2011 Audi A4 have a timing belt or chain?

The 2011 AudiA4's 2.0L 4Cylinder engine is driven by a timing chain. There's no recommended service interval, so long as You're keeping up with regular oil changes and maintenance; if You are, You can typically expect the chain to last the lifetime of Your A4, or about 250,000 miles. Of course, c**p happens. Your timing chain may become stretched or otherwise damaged due to faulty timing chain tensioners or other issues. This is relatively uncommon, but unfortunately expensive; a timing chain replacement can cost You upwards of $3,000, not including the engine damage that the failure caused. You'll want to be sure You religiously follow maintenance in hopes of avoiding this cost; take care of Your A4, and it will take care of You.