Well guys I decided to replace my leaky oil pan gasket on my 1990 F150 with the 4.9, decided to do the oil pump as well because it has low oil pressure when warm at idle. Pulled the pan and to my horror found CHUNKS of thin metal and lots of dirt ... The motor has over 300K on it and runs like a top (minus the low oil pressure) it has never knocked or have me as much as a hick up. Does anybody have any idea what this could be from? Bearings look fine, only thing I can think is cam bearings.

 

i wouldnt worry about it unless its brass looking. lots of these clowns that assemble engines throw the trash in the pan for some reason i will never understand. maybe angry at the boss? heck old 70s fords youll find factory tools in the tail light holes of the bed sometime. ive even found one in my in cab gas tank once.

 

In the mid 80's when I worked for Ford we had a brand new station wagon that had a thunk in the left rear quarter panel area. It was a coke bottle thrown down inside the panel before the interior went in, as skip said we just figured someone at factory was pissed at boss that day.

 

Can you tell what the metal is? Aluminum or cast iron.

If you have cast iron and the motor is fine my guess would be casting slag that did'nt get caught at assembly. It just worked it's way down into the pan. Too big to be a bother so they just sit there and wait to scare you! I've come across the same thing in the GM motors.
Never the less look hard for something that doesn't look right.

 

it looks like, from the poor picture detail, like a broken piston skirt. that happens from time to time with cast pistons. its also possible that the PO "rebuilt" the engine, and left the junk in the pan because he couldnt be bothered to clean out the pan.

now if you find some thin piece of metal in the pan, then i suggest checking the bearings carefully.

 

Any chunks with serial or part #s? That's bad.

 

Are they magnetic?

 

get a better dang picture of the chunks cleaned and on a paper towel.

 

Well said.

I can see the OP finger prints better than the metal

 

I had a similar situation when I changed the oil pan gasket on my 94 5.0. Found a few small chunks of metal in the pan. I cracked my oil filter on the next change didn't find any metal in the filter so I didn't worry about it. Like the above replies Philly just junk that didn't get cleaned out.

 

Agreed. You need better pics but I'd say if your engine is running fine and especially if you have good oil pressure after the repair, I wouldn't give it too much more thought.

Also as suggested, cut open your oil filter. I do this every so often just as PM. If anything is coming apart you'll find the evidence there. Be careful when cutting not to contaminate the filter media with metal shavings, using tin snips works best.

 

Look at it this way, you have received over 300K miles from this truck and if you use it on the farm where a failure would just be inconvenient put the pan back on and drive it. You can start now planning on replacing the truck or the engine in the future. Low oil pressure when warm is not a big deal on a farm truck. I would look for a bargan on a replacement engine and when it shows up do the swap. Those pieces could be piston skirt and depending on how big a piece fell off this may not be an issue at all.

 

i knew a guy that would cut all his piston skirts off, he claimed he engines revved faster because of it. so its not a bad thing.

 

Ok I can see the logic, less rotating mass the quicker response to throttle changes. However a couple possible downsides - unbalanced engine if weight between piston differs, more of a chance that pistons will tilt in the bore - meaning quicker wear - so perhaps giving up longevity for throttle response ? Just possible trade offs ......