93 Festy Engine Knock Question?

[PuddleJumperRic]

My 1993 Festiva devoloped a loud knock coming from the bottom of the engine. Pulled the oil pan and shook each connecting rod to crank. Found one loose, but all others seemed tight. So I pulled the loose bearing and found it to be spun. The crank shaft looked pretty good, with a little dis-coloration. So I went to the local parts place and bought a set of all 4 rod bearings, because they would not sell me just one rod bearing. The crank shaft lobe on the 3 tight bearings and the bearings looked fine, but I replaced them anyway, since I had them. The bad (Loose Bearing) crank lobe looked a little worn, but no deep scratches were present. So I got some emory cloth and cleaned up the crank shaft lobe area the best i could, and installed the new bearing. Put it all back together and poured in 4 qts of high milage oil and a new filter. Started it up and no more engine knock. But for how long? I know the correct way to fix it would be to pull the crankshaft out and replace it with a Crank kit and all new bearings, but I decided to take a chance since I already had the pan down, and the bearings were cheap. Has anyone tried this? I would like some comments, suggestions, words of wisdom, ect. I am clueless as to why the one bearing took a spin and all the others were in tact? Any ideas?
Thanks a million for reading my post,
Rick :lol:

[Festy46]

I did your "in-car crank repair" to a Minneapolis Moline farm tractor one time and it lasted for years. I didn't use it that often and the maximum rpm of the engine was only around 1500. It's impossible to give you an estimate of how long it will last. When you had it apart, you should have measured the crank journal to see if it was under sized or "egg shaped" (not perfectly round). At the very least you should have checked the rod clearance with a piece of plasti-gauge. If the crank wasn't hurt more than a couple thousanths, it may last a long time. I wouldn't want to make any long trips with it (like several hundred miles from home).

As far as why it happened. The oil passage may have been blocked by an obstruction. It may have been a piece of metal from when the holes were drilled in the crank at factory or some dirt. It's also possible the crank journal may have been under sized and/or the wrong size bearing installed.
It's one of those things you chalk up to "$hit happens".
John

[yvanlavoie20]

i made it

on my 92 yj i made the same thing...i ran over 25 000 km this year and run great.

good luck

http://members.cardomain.com/yvanlavoie20

http://www.fordfestiva.com/members/Yvan/yvan.htm

http://www.fordfestiva.com/multimediaandfun/gallery/yvan/yvan's_bp_turbo_swap.htm