Magnetic Oil Filters

[Jason]

The above video is speaking about placing magnets on an oil filter, with the idea being the magnets will trap any metal particles in your engines oil in the filter.

I am curious if this idea holds merit with a couple changes, those being:

1. Stronger magnets. The ones used in the video look pretty weak, and thus give me cause to doubt their ability to attract metal particles in moving oil.

2. More coverage from the magnets, meaning placing them in more than one area of the filters surface.

Given these ideas, is this a good idea, or is it more snake oil from another purveyor of old wives tales?

Topic

[James O’Hara]

It is an interesting Idea. I wouldn’t say its a bad idea though I would say it was rather poorly implemented. Some drain plugs plugs are magnetic its the same basic idea though when you remove the drain plug it pulls the metal shavings out. Some are left behind but, at the speed the oil comes out it should remove all the particles. They have magnets in all transmissions to help keep metal out of the system so the idea is solid from that perspective.

My issues with doing it at the filter have to do with restriction of flow and possible loss of magnets. When you collect the particles like that in one spot around a restriction which is what the filter is you can get a buildup which will block off part of the filter now you have an even bigger restriction oil pump has to work harder and you might not get the flow you need. The other issue is if you build up all this metal and a magnet drops out the metal is now all concentrated in one area. That combined with the force from the oil pressure could be enough to blow out the paper (filter membrane) causing you to have no filter at all and also send a bunch of metal through at one time which the engine would not be able to handle as effectively as very fine particles over time. AKA it will mess stuff up.

If you use more powerful magnets you are going to have fun getting them off of the filter and its also going to pick up metal shavings from all over the road ie rotor dust etc. If I was going that route I would either get a magnetic drain plug of good quality or a very strong magnet with a way to remove it stuck to the oil pan in front of the drain plug and remove it before each time you drain the oil. Computer hard drive magnets come to mind.

All that being said there is also the fact that most engines now are aluminum almost everything. Aluminum is not magnetic and where you have aluminum and steel rubbing aluminum is going to loose. You still have races, bearings, and other wear surfaces that are magnetic metal though.

[Jason]

MDK22, you make some valid points and I do tend to agree with said points. Something I’ve been mulling around in my mind about this, is if you have enough metallic particles in your engine oil to be worrying about trapping them, then there are bigger issues within an engine than what this article was intended for.

Now with that said, maybe it could make a small difference in an engine with a steel oil pan, however, I think taking care of your engine to begin with is a far better measure of longevity.

Now, just for my own fun and curiosity, what would be the consequences, if any, of using a rare earth magnet with a pulling force somewhere between 25-55lbs, on the oil pan to catch any particles? Would the force of the magnet disrupt the movement of the crank in any way? Would using a more powerful magnet, say 250-500lbs of pulling force have an impact?

Allow me to quell any concerns real quick and say that I would not use a magnet that powerful, if I were to use one at all, for fear of damage from attraction of road bound debris.

[Bluesnut]

Snake oil in my opinion as the amount of metallic debris is negligible unless there’s a major problem. If there’s a major problem then magnets are the least of the worries. Changing the oil regularly is the best option.

Any wear material from bearings and bushings will not stick anyway as it’s non-ferrous.

[Author]

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