Are magnets for an oil filter and a magnetic drain plug a waste of money?

[sloinker]

If the magnet wrapped around the filter is large and strong enough, it may trap the polar aspects of the oil in the filter and the remaining oil may not cling to the parts of the rotating assembly it needs to. Thus guaranteeing a short sudden death for your engine. j/k
Magnetic drain plugs in all my vehicles. I have never seen anything stuck to them when I change oil so.....

 

[Reloader59]

Not worth it to me. Only catches ferrous metals.

 

[72C10]

I do have a few magnetic drain plugs, but I think for your engine oil they are mainly useful to detect catastrophic failure.

I find them most useful for transmission and differentials as far as catching metal.

 

[UncleDave]

Yes as a diagnostic tool. Classic drain plug.

Yes as a particle reducer in high load vehicles, trucks towing, motorhomes, boats, construction equipment, and vehicles running extended OCI's. A mag on the filter or even in the stream has a greater chance of capturing due to proximity.

Ferrous metals are the metals under the most load anyway.
Other particles can occasionally stick them electrostatcially, but thats not consistent.

Jim Fitch at Noria has done great work worth looking at.

 

[twX]

I bought a magnet plug and the magnet came out of it after a few years. Aluminum pan so who knows where it ended up?

If it's not sitting at the bottom of the oil pan, it's probably stuck to the oil pickup screen. I doubt it could ever cause a problem.

I bought a cheap one that had the magnet fall out before I even installed it.

 

[Hootbro]

I have looked at magnetic drain plugs as being more for the feelz that one is doing something constructive than it actually being measurable value added thing over the given life of a vehicle.

 

[Gasbuggy]

I always loved the GM pan bolts with magnetic tip. Before I started cutting oil filters, it was the only warning I had

 

[KevinMalone]

I stopped messing around with magnetic drain plugs after seeing the issues other had with them (magnet coming off, drain plug shearing, etc). The questionable benefits do not outweigh the potential risks IMO

 

[UncleDave]

I stopped messing around with magnetic drain plugs after seeing the issues other had with them (magnet coming off, drain plug shearing, etc). The questionable benefits do not outweigh the potential risks IMO

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Looks like imported ebay stuff vs brand name like gold plug.

Filter based mags do a better job anyway and present zero risk.

 

[SHOZ]

This is what I worry about - was it a name brand like Gold plug?

Yes it was a Super Magnet or something like that. Stainless Steel so non magnetic. Been quite a few years ago. It was for the V8 SHO Taurus that you had to weld the cam sprockets to the cams while in the car. Took about 5 changes before the weld splatter was all trapped....

 

[Al]

Probably, thats why I bought them

 

[21_6.7f450]

I use Gold plugs on oil pans, diffs in the Toyotas because the diesels have Mag-hytecs, all transfer case drain plugs and trans drains, basically everywhere I get gets a Mag-hytec or Gold Plug It catches black metallic goo.
I absolutely believe in them. The less metallic goo and savings circulating eroding seals and causing particle streaks in bearings. As an experiment, because some also say Filter Mags are a waist because they say the oil filter would catch "that metal". I took off Filter Mags and the drain plugs had more goo, not much but noticeable. So I don't believe the filter will catch all the metal going through it, only larger pieces.
I put the oem plugs back on and slapped rhe Filter Mags back on, the inside of the can had a bit more black goo. Yes, with a good oil filter, a quality magnetic drain plug and Filter Mags ALSO help. I belive in all three.
If I had to rank most important to least, I'd say oil filter, Magnetic drain plug, then filter Mags. I run all three on everything except the 2gr-fks uses a cartridge and the 6.4.

 

[dguzzi]

I put hard drive magnets on the outside of all my filters. Very strong and any particles they stop from circulating is a win. Free and easy!

 

[Mewbs]

I stopped messing around with magnetic drain plugs after seeing the issues other had with them (magnet coming off, drain plug shearing, etc). The questionable benefits do not outweigh the potential risks IMO

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You get what you pay for. Buy cheap, get chineseium. Also cheap non SH Neodymium grades will loose their magnetism overtime as off the shelf grades are only rated up to 80C will irreversibly loose their magnetic strength over repeated heat cycles, average oil temps are around 100C.

 

[Urshurak776]

I have a magnetic drain bolt in the KIA Rio. It does catch a little bit of fuzz, not much.

 

[BobsArmory]

I have used a Filtermag on my wife's car since new. Always fun to cut open the filter and see the image of the magnets on the inside of the can from the metal it attracts. They are kind of pricey but the one I bought for her car in 2016 is still so strong that I don't want to have my fingers between it and the filter when i put it on.

Just got one for my truck. I'll parrot the others. Don't know if they actually do anything but it can't hurt.

Filtermag Website

 

[spasm3]

I make my own drain plug magnets. Samarium cobalt magnets don't lose as much gauss as others when heated.

 

[BobsArmory]

If the magnet wrapped around the filter is large and strong enough, it may trap the polar aspects of the oil in the filter and the remaining oil may not cling to the parts of the rotating assembly it needs to. Thus guaranteeing a short sudden death for your engine. j/k
Magnetic drain plugs in all my vehicles. I have never seen anything stuck to them when I change oil so.....

Truth. As a matter of fact, SpaceX only uses non polar lubricants in their rockets. If they did when they pass thru the earths magnetic field the oil would blow out the bottom of the oil tank.

 

[oil pan 4]

Drain plug magnets trap 25 and bigger like 1,000 microns.

https://www.machinerylubrication.com/Read/600/microscopic-debris-analysis

 

[ZeeOSix]

Drain plug magnets trap 25 and bigger like 1,000 microns.

I'd think strong magnets trap ferrous particles less than 25u too. If you look at the typical "black paste" collected on a magnetic drain plug, most of that debris has to be smaller than 25u. A lot of that debris is probably what can be detected by an ICP type UOA as iron in ppm. I'd think that magnets taking out iron would help reduce the reported ppm of iron in a UOA.

Here's an interesting post. The link to the study is broken now. But the conclusion was mostly composed of particles under 10u.
https://bobistheoilguy.com/forums/threads/effect-of-a-magnetic-drain-plug.130432/post-1867462

Also ...
https://bobistheoilguy.com/forums/threads/effect-of-a-magnetic-drain-plug.130432/post-1868711