 My wife bought her CX-7 used with around 40,000 miles. Timing chain broke at 60,100 miles. No check engine light until car actually stopped running (in passing lane on busy interstate). Mazda is replacing the engine right now, no questions asked, despite her not being able to find all her oil change receipts. I suppose we have to thank everyone else before us who had this problem and complained, otherwise we'd be in the same boat. This thing apparently develops other problems that we don't want to to have to deal with, so as soon as it's fixed, we're trading it in!!!