Don't know about Centreville, but there's a shop in Chantilly I trust. The owner/mechanic, Hamed, is a longtime friend and is trustworthy. His rate isn't incredibly cheap or expensive, but I trust him, so I take my car there. He'll explain things to you in detail, but in plain english if you ask.
https://www.facebook.com/pages/Advanced-Auto-Repair-Inc/510056702338544