I have a 1995 (Lincoln) 4.6l that has 7 cylinders with good compression and 1 with zero. I just brought it home so I haven't diagnosed it myself yet so are there any things I should check first to save some time and money? I try not to assume worst case until I exhaust all other senarios. It has 150K miles and runs rough and smoke (black) when you get on it. I don't know the history on the car before I got it. Will any 4.6l from a salvage yard work??

Any pointers are appreciated

 

Somthing to consider with the problem your having, cylinders will vary some what in compression test even when you got bad rings or blown gasket ive personally have never had one read a flat zero on a compression test. If I were you id be looking into the possibilty of a valve stuck open! if you had a intake stuck in a open postion that could possibly explan the zero compression reading and the black smoke maybe. Im like you when it comes to car work it is a science of sortsand like any sceince it isa simple matter of deductive thinking and reasoning. I wouldnt go into timingbelt concernsbeing that it would be likly to effect all cylinders or at least more then one. as far as swaping for another 4.6 L i dont know much about them personally but i do think there are some with and some without over head cams and there may even be a couple diffferent over head cam models that offer 4 valve per cylinder and some are like 5 valve per cylinder somthing like that I wouldnt swear to it but there is a few different kind 4.6 L out there so make sure you know what it is you got is the main point. The blocks on these different 4.6 maybe the same but i couldnt say for sure so id do a little reserch into the matter if you go to buy another one. good luck hope you get it figured out. let me know what you find out maybe the engine isnt as bad as your thinking,,, it may be bad shape,,,but it never hurts to do a little investigating...