97 f150 with a knock

i want to purchase a 97 f150 with a knocking motor. its a regular cab, 4.2 v6automatic with 123k miles. is this common on these motors? could it be something besides the lower end? worse case schenario, is it possible to remove the oil pan with engine installed? i want to make sure i know what i am getting myself into before i actually committ to purchasing it. thanks for all the help.

I had a knock in my motor actually more like a tick but my mechanic buddy said something was going. Talked to another buddy he said check plugs, one was a little loose causing the tick. Guess what im getting at a long shot but check plugs...

i guess it could be anything but my real question is can the oil pan be removed without pulling the motor? i am assuming worst case schenario that it is a lower end knock.

You can get the pan off most of them, eventually. LOL Some are damn near impossible, but with enough jacking , twisting, beer and cussin, you can usually get em off. Ive never tried it on a 4.2, and wouldnt anyway. I always pull em out anymore, and have found for me, that its quicker in the long run. Plus, i dont like rollin around on my back with oil dripping in my eyes. But seriously, youll probably have to take the motor mounts loose, and maybe the trans mount too. Sometimes the exhaust has to come loose also to get it jacked up high enuff. The crankshaft counterweights sometimes get in the way, and youll have to rotate the crank to get clearence. Before i went thru all that though, i would get a mechanical oil pressure gauge and check the oil pressure. Something caused it to start knocking, and odds are pretty good that it was oil related. If the crank is damaged, youll be better off pulling it and doing right, which i suggest anyway. In the time you spend rolling around under there and fighting with it, you could have it out where you can get to it , fixed and back in. Thats alot of work to do a patch job, and have to do it over!!!

i had a knock in my 97 f-150 and all we did was change the 02 sensor i have no idea what they have in common but the mechanic i was workin with a the time said that he had seen it before and it worked so maybe that could be your problem

i had a knock in my 97 f-150 and all we did was change the 02 sensor i have no idea what they have in common but the mechanic i was workin with a the time said that he had seen it before and it worked so maybe that could be your problem

Hi-
I am new here but you describe the same scenario I have with my 97 F150. My engine is a 5.4L and I wondered what engine you had? Changing an 02 sensor sounds like an easy and cheap fix. It makes a knock typically only at start up and may sound like a machine gun (as far as speed but not real loud) off and on for a mile or two. Usually it stops but once in a while it may come and go for a few minutes. It does not seem to affect the way the truck runs as it still has lots of power. It just sounds like something that is going to turn into a big problem if left go. I have always ran Mobil1 synthetic oil in the truck since I bought it with 32,000 miles on it. It has 107k on it now. With synthetic I wouldn't expect sludge problems like with regular oil. Any ideas?
Cheers