Anyone use magnets on their oil filter?

[Ray H]

The head-positioning magnet out of a hard drive is the one worth going for. (That semi-circular magnet depicted in one of the above photos is a head-positioning "rotary voice coil" magnet. Uncharacteristically strong for its size) In addition to ferrous metals, chromium and cobalt also have robust magnetic qualities. Cobalt-doped iron oxide has nearly the same magnetic properties as pure chromium dioxide in magnetic video and audio tape. Given that chrome is HARD, and is used in engines, it's not a material you'd want floating free as sharp-edged particulates in your engine oil if you had a choice in the matter. As to the ridiculous worry that snagging iron and other metals magnetically would skew a UOA, BIG DEAL! If it's left in the oil, it can only cause accelerated harm as additional wear metal sloughing until the next oil change - and THAT, folks, is also skewing the UOA results.

 

[Vstrom]

Years ago I remember hearing some didn't like magnets because of this theory- A ferrous particle could stick to a magnet then come loose. It is now magnetized and could stick somewhere bad, like in a bearing, that it *wouldn't* have stuck in had it been non-magnetic

 

[Shaman]

Another point I want to bring up, is how would a powerful magnet effect the other functions of a filter, and say the things mounted above it, like the bypass vavles in GM products.

 

[Gary Allan]

Well, the good and bad about the magnet that you drop in the center hole ..

You get to see what it picked up - good

You get to see what got past your filter - not good