When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
Maybe timming belt is broken. I don't know if pistons will hit valves or not on your engine. I saw such a thing once. You can open oil cap and see if valve moves when you turn engine over.
Does it crank real fast... or faster than usual? If you don't have any exhaust leaks, and you cover the exhaust and crank it... and it doesn't build up pressure, the timing belt is hosed. It's another less-technical way of checking the belt.