[jacquesm]

That's why you test-drive a car and/or have it inspected. If it is a clunker and the price of the inspection approaches the price of the car you can just take the risk. In any other case an hours worth of time of a competent mechanic will tell you all you need to know. After that the risk is yours if you decide to go through with the purchase. If something does turn up that wasn't disclosed the seller will usually be happy to adjust the price. And if not you are only out the inspection fee. Typically $50 to $150 so well worth it on any vehicle purchase that is in the price range where 'engine fell out' feels like it isn't on the menu of expected events.