So, hopefully someone here can give me some insight. Let me preface this with the statement that I am an automotive tech with 12 years experience on BMW and Porsche. I purchased a 1997 Ford E150 with 4.2L V6 for a steal for a carry all. I drove it for about a year when it developed an extremely bad top end knock. I pulled the engine and tore it down and sure enough it had dropped two valves. I have a friend who works for a dealership so he got me a reman. engine for cost, finished putting it in the other day and started it up. Initially there was a good bit of smoke (white) which I thought was extremely odd but the exhaust did have some coolant in it from the valve drop, it cleared up in about 5 mins. Then the knock developed, it sounds like the damn thing has a rod knock and has spun a bearing, additionally it has a rough idle and no power. I have never dealt with FORD reman parts but I did have a factory engine from BMW come in and it spun a bearing on start up a few years ago. I have gone over the engine from top to bottom nothing is loose, no fault codes and all the wires are good and connected, someone stated it might be a bad wire and spark knock on this engine. No go, so any ideas???

 

My 98 4.2 started making a noise that sounded like a bad bearing in the alternator or the water pump but did not disappear when ran with the belt off. The noise in time seemed to change into more of a knock and even appeared to be louder when the engine was under a load. This continued to the point where I was sure that I had a bad rod bearing and it was only after pulling out the engine did I discover that the belt pulley on the crank had two loose and two broken bolts and was bang around