bearing knock
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Elder User
Joined: Dec 2002
Posts: 550
Likes: 1
From: Effingham,IL USA
bearing knock
i got an 83 f100 302 with 150kplus miles on it. its never been apart and the bearings knock pretty good. the oil pressure is low, so i run 40 wt in the summer and 20w40 in winter. this raises the pressure a little. has anyone changed the oil pump on an engine like this and had an effect on the knock? i mean the old oil pump is worn and delivering less pressure than when it was new, so by puttin a new pump in it will pump more oil and increase the pressure and i'm thinking that extra pressure could be enough to keep the bearing from slapping around as much on the crank journal. i changed the oil pump on my 66 mustang a few years ago and the oil pressure increased a lot. that engine still had good bearings so i'm wondering if a new oil pump fixed or lessoned the knock on anybody elses engine? 
Posting Guru
Joined: Aug 1999
Posts: 1,485
Likes: 3
bearing knock
Ive never seen an oil pump change "fix" worm bearings. A cheap attempt to prolong the inevitable is to try adding a quart of Lucas oil treatment to your next oil change. Im not a believer in most "snake oil" products, but in my experience Lucas works very well. Just remember, its temporary.
Nathan
Nathan
Post Fiend
Joined: Feb 2001
Posts: 6,624
Likes: 8
From: Missouri
bearing knock
Nope, my 360 was knocking real bad and I was running straight 60W with lucas by the time I tore the engine apart. Thicker oil helps a bit but nothing will fix it except a proper rebuild. From the shape of the rod bearings I don't even think that they were worn out. I almost think they were the wrong size. 
It knocked the day I bought it and I planned the rebild from the purchase date.
It knocked the day I bought it and I planned the rebild from the purchase date.
Senior User
Joined: Jun 2002
Posts: 423
Likes: 0
From: Oklahoma
bearing knock
Installing a hi-volume/hi-pressure oil pump, going to thicker oil and/or adding an additive are simply bandaids. If you are going to pull the pan to replace the pump, you might as well install a new set of new bearings while you're there (plus all the above) and hope for the best.
New User
Joined: Jan 2003
Posts: 9
Likes: 0
From: holly hill usa
bearing knock
here is the deal, knock is caused by wear(or worse). the only way to correctly fix the problem is by reducing the amount of clearance at the bearings(new bearings) i have on occasion stretched the spring inside the oil pump, or bought a heavier replacement oil pump, and helped the problem, but i say, if ya got the pan off, why not fix it right anyway? just my opinion. good luck.
Elder User
Joined: Aug 2002
Posts: 662
Likes: 0
From: CA
bearing knock
You say the rods knock pretty good? First, try to figure out which rod(s) are knocking. You can do this at idle by pulling each plug wire (use a thick rubber glove and be careful) one at a time. Then when you get the pan down, inspect those rod journals and rod big ends very carefully with a micrometer. If the journals or ends have been knocked a bit out of round, or the crank has other damage, you'll need to get it fixed or the new bearings won't last long either.
