Will a magnetic drain plug affect my UOA?

Messages
210
Location
Reno, NV
After I changed my oil today I looked at the drain plug that I put in at the last change and I could see that the tip was completely covered in small metal dust. It was very apparent after I wiped the drain plug. I was about to send my used oil to Terry for an analysis, but was wondering how skewed my results are going to be. Any input is appreciated. I didnt really research this (how the drain plug affects OUAs), but figuered I ll find an answer this way. Thanks.
 
Messages
7,077
Location
Ontario, Canada
I just got a UOA showing 33% less Fe than in last summer's sample, but the drain plug had about 200% more metal powder buildup. Either the particles caught by the magnet are too large to show up in the UOA, meaning the UOA is useless, or the magnet really did pull almost all the iron from the oil. Anyways, it'll only affect iron and nickel readings if it skews anything.
 
Messages
32
Location
MI
So it is better to have a drain plug with a magnet? or one without one? I just replaced mine with a magnetic one. Should I replace it with the non-magnetic one at the next oil change? Brian
 
Messages
7,077
Location
Ontario, Canada
I'm keeping my magnet, since iron particles could be abrasive to soft metals, and they also might be catalytic and speed up oil oxidation. I might try one run without, just to see if the UOA shows more iron.
 
Messages
7,409
Location
Austin, TX
Quote:
I just got a UOA showing 33% less Fe than in last summer's sample, but the drain plug had about 200% more metal powder buildup. Either the particles caught by the magnet are too large to show up in the UOA, meaning the UOA is useless, or the magnet really did pull almost all the iron from the oil.
Or...the metal powder would of been caught by the filter, or sludge (if there is any), or just settle to the bottom of the oil pan. Conspiracy solved, and you may look forward to longer filter life.
 

JAG

Messages
5,320
Location
Fredericksburg, VA
My one magnet is on the filtered oil side of the inside of the oil filter. It still picks up iron debris though they are very small in size, as they have to be to pass through the filter. The maker of my magnet claims this magnet does reduce iron levels in UOAs but I haven't tried to verify it. It seems from others' experiences that drain plug magnets pick up larger particles and it would not surprise me if they had none to little effect on UOA iron levels due to the large size particles they pick up...but I dunno the truth.
 
Top