You will have to drop the sump and check the bearings, but the description you have given it does sound terminal. Probably it has spun a bearing, when an engine does this, it will knock and falter as the 2 bearing 1/2's spin together then they are pounded and the engine revs hard until the engine locks up, if this is the case, look for a second hand engine as a cheap option.
Thursday, January 9th, 2014 AT 8:51 PM