metallic debris in filter


The Grumpy Grease Monkey mechanical engineer.
Staff member
Did oil an change over the weekend, Drained and the oil and nothing looked out of the ordinary then I decided to cut open the oil filter and right away saw metal shavings, The engine has about 343 miles on since rebuild but it has had numerous oil & filter changes because of issues with fuel starvation and carburetor running real rich. This past oil change has the most street driven miles since rebuild. Once I did the oil change I decided to pull the valve covers and found some fine metal shavings sitting in the heads.
all that extra silicone sealant that gets squeezed out off the gaskets tends to get carried by the oil flow into the oil pan where some of its trapped in the oil filter during each successive trip thru the engine, but bits that get trapped in the oil passages can rapidly reduce oil flow and destroy bearings, cam lobes and rockers and lifters.
I do have the Oil bypass blocked but is this something I should be worried about or is this normal for freshly build engine.
Running a Wix # 51061 oil filter

MMO is NOT an oil additive!, its simply a rather thin viscosity, high quality, automotive and machine oil,
with a high level of sludge solvent, and friction reducing additives.
that works well at breaking down and holding in suspension micro contaminants ,
so the oil filter can trap and hold them.
its not a miracle cure for anything but it certainly helps keep engine parts cleaner,
and its well documented to help free up sticky moving parts over time






1/8" metal hardware cloth and high heat magnets are good for catching crap like valve keepers or broken rocker parts

keep in mind all that metallic trash, cycles through the oil pump BEFORE it reaches the oil filter


looking at the picture of that oil filter I can remember doing it that way decades ago,

finding small bits of metalic debris in a recently rebuilt engine is very common, installing magnets and shrapnel screens certainly helps reduce the amount of crap reaching bearings
it looks like it was cut open with tin snips and while that obviously worked it also potentially introduced metallic debris into the filter that would not have previously been there, you might want to invest in a tool designed for filter inspection, while you might look at it as an un-necessary expense, Ive found it makes life a bit easier and reduces the tendency to cut yourself on jagged filter edges


many guys use a stainless steel strainer with a magnet in the bottom to catch oil as it drains to locate engine trash in the oil,


Proform Oil Filter Cutters 66490 - Free Shipping on Orders Over $99 at Summit Racing

Summit Racing® Oil Filter Cutters SUM-900510 - Free Shipping on Orders Over $99 at Summit Racing

while I generally use stainless 6 or 8 mesh screens theres lots of options that will work just fine, just remember to keep the oil changed regularly or theres some potential for sludge to clog ANY size shrapnel screens ... 6T0350W36T ... 8S0280W36T
it should not take a great deal of imagination to see that a broken rocker, lifter or push-rod could dump metalic debris into an oil drain back port that wold rapidly result in increased internal engine damage as a result.

IVE typically used these magnets in an engine, one in the rear oil drain on each cylinder head, one near each lifter gallery drain and 4 in the oil pan sump
proper magnets trap metallic debris
SmCo Samarium Cobalt Disc Magnets
many magnets lose their magnetic pull if heated to 200F
these below won,t

Samarium Cobalt MAGNETS HELP
magnets are ceramic and glass hard, don,t try to drill or grind them, as they can shatter



Ive generally used hardware stainless screen epoxied over oil drain holes, and ceramic magnets to limit broken valve train debris reaching the lower crank case
proper magnets trap metallic debris
SmCo Samarium Cobalt Disc Magnets

Samarium Cobalt MAGNETS HELP
magnets are ceramic and glass hard, don,t try to drill or grind them, as they can shatter
Last edited: