That is the problem we are having, that is all the mechanic can tell us -'it is coming from the bottom'. He said to pull it apart, find the problem and rebuild it would cost us over $10g's. I was wondering if we can troubleshoot it first, maybe check things like compression, injectors, tappets?? I am not a mechanic - so I dont know if this is possible. The lowest quote for a second hand engine has been $7500, can you find them cheaper- as there is labour involved if we do need to replace it. Just a bit frustrated and confused as to what to do.