If you were 4 qts low, you had about 1/2 to 1 qt of oil in the engine which most likely starved the bearing for oil. Does the engine need replaced? It really is based on how bad the knock is and where the damage was done. You may be able to drive it the way it is for some time. There are different additives you can purchase that may help get rid of some of the noise, but the damage is already done. Also, if the crankshaft wasn't damaged (only a bearing), you may be able to get away with just replacing the rod and main bearings. That wound need to be checked when the engine is taken apart.
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Sunday, January 9th, 2011 AT 11:27 PM