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Why Not to Buy Oil Filter Magnets for Your Car – Myth Busted

Why Not to Buy Oil Filter Magnets for Your Car – Myth Busted

rev up your engines! today I’m going to dispel the myth of
magnetic oil filters, it’s come to my attention recently from some of my fans
said, hey Scottie you can buy these magnets that you stick on your oil
filter and it’ll keep all the metal pieces in from ruining your engine, what
do you think of that, well to really understand it, I’ll give you a little
history lesson, originally cars didn’t even have oil filters, but in 1923 a
company’s that was later called Purolator for pure oil later, evented
the first modern oil filter you could put on cars, a few of the high-end cars,
they put these filters on them and in the 1930s, some motorcycles and cars
tried out a magnetic based oil filtration system, but that didn’t last
very long it went by the wayside, now when I was a young mechanic in the 1960s, a lot
of the cars did not even come with oil filters, it was an option you could add
on, but a lot of the cars they didn’t have one, we had a Ford that we
just changed the oil every couple of thousand miles in it, because it didn’t have a filter, but as we go to present time I notice there’s a lot of places that are
selling these and on magnets, you can stick on your oil filter, well what
should you think of that, they come in various shapes and sizes, this one has a
plastic band of magnets that fits on the outside of the filter, this one fits on
the outside on the top of the filter and just comes on and off when you change
the filter, but they all are the same theory, the magnet is supposed to hold the
metal pieces inside, so it doesn’t do any damage to your engine, but really that’s
what the filter does in the first place look at this, this is a premium filter,
99% efficiency at filtering stuff out right here, it filters down to small
microns, if you have anything in there it’s going to filter it out in the first
place, and if you think about it, a magnet holding in metal pieces is the least
of your worries, if you actually have metal pieces inside your engine, you got
a problem inside the engine where the metal is breaking down, and no magnet is
going to fix that that’s like closing the barn door after
the horses have already run away, realize that the important thing is to change
your engine oil and filter regularly not adding some kind of snake oil
magnet to your oil filter to save you and I know a little bit about snake oil,
this is Kilmer’s swamp root, kidney liver and bladder remedy snake oil, one of my
distant relatives used to sell that in New York State in the eighteen hundreds,
so don’t be fooled by buying magnets and sticking them on your oil filter or
your fuel line either, they don’t do anything their, fuel is not magnetic
it doesn’t affect anything of your fuel either, so if you never want to miss
another one of my new car repair videos, remember to ring that Bell!

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100 thoughts on “Why Not to Buy Oil Filter Magnets for Your Car – Myth Busted

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  2. Typically there's a magnet built into the drain plug, keeping metal pieces from blocking the pickup screen and tube, protecting the oil pump….long before it reaches the oil filter!!!

  3. People make all sorts of modifications to their vehicles. The manufacturer hires PhDs to figure this stuff out. It's not likely they missed anything.

  4. Magnets work well just youtube lube for the dumb. I use two large earth metal magnets by my oil pickup and extra one in trans pan. And the nice oil filter type. I taken things apart and the metallic sludge build up is Absolutly crazy. It helps a lot and why would you discredit anything that works. If it makes sense to you do it. Opinions are like in-laws everyone's got em and they never go away

  5. Why don't you try it and cut open a filter to see if it actually does something before you say it doesn't…It's called swarf by the way mr.mechanic…

  6. If I am correct, engine now are mostly made with nonferrous metals. So those would fail to get most of the metals in the first place.

  7. Why not buy it? because imagine the joy you’ll have when that magnet accidentally fall off after it’s been collecting some amount of debris…

  8. Dear Scotty I own a car and pickup and several motorcycles I decided to buy a premium oil filter and change the oil every 2,500 miles and the filter every 5000 or thereabouts. Is this okay you think. How long should I expect a oil filter to last before the paper filter element disintegrates and comes apart?

  9. Scotty you and I are the same age 101st and all that.
    I usually agree with all your wisdom but not on this one.
    99% in filter ,1% stuck to magnet. The real real fine crap the the filter cant grab. Been using mags for yrs.
    Always get 400 thousand or more from all my motors.
    Also kero my pan at oil changes to get sludge out of bottom.
    Im a long hall trucker for the last 41 yrs.
    Motor kote is phenomenally phenomenal too
    Never had a major problem using it in a Detroit 60 series.
    Have logged over 6 million safe miles.

  10. I have a number of problems with your comments. FWIW, I too have been wrenching since the 60's.

    Why then do OEMs put magnets in the transmission pan? When you drop the pan it is covered, which is normal. Granted, there may be more ferrous wear items in the tranny, but in the engine, they are not totally absent. Some OEMs used magnetic engine oil and differential drain plugs that were effective in trapping particles.

    Most oil filters are 25 micron filters and are not 100% effective passing some suspended debris, far from it. You should read the fine print on your Bosch "99.9 % efficient" filter. "*Based on ISO 4548-12 at 40 microns on D3500 **Compared to conventional filters" That is marketing hype and complete nonsense. 40 micron!!

    Finding small metal pieces in the engine oil is NOT a sign of a problem, especially on a new engine. All things mechanical wear. That wear is the removal of material as a result of friction and other causes. What is the material engines are made of? There is some common sense for you to ponder.

    Magnetic traps are very common and effective in industrial hydraulic systems. Not that much different than the oil systems of modern engines.

    Considering one could purchase neodymium bar magnets suitable for the outside of a spin on filter for less than a $1 each, why not? Placing 4 or so on the filter body is neither difficult nor expensive. The goal should be keeping your oil as clean as reasonably possible. $4 to me is reasonable.

  11. Essentially what you're saying is, why add an extra layer of protection. So, why use a furnace filter, when my home filters the air? Why use vitamin C when my body creates anti-bodies? Why put injector lube to my diesel when my diesel is supposed to have added lubricates? I respect your opinion, but I think there's nothing wrong with keeping an extra layer of protection in a motor, especially an older block. I've torn down enough 302's and 350's to know what shavings look like. Cool video, though!

    P.S. You didn't really "dispel" any myths. You gave conjecture. Until you show me concrete evidence that adding mags to a filter does NOT net shavings or particles, I will respectfully disagree.

  12. The magnet catches very fine metal that the filter can't stop. If you run full synthetic motor oil, your car will last longer with regular oil changes. Maybe with the magnet, even farther. I would think the very, very fine metal that comes from normal ware can be stopped with a magnet. Your right, a oil filter will stop big particles of metal and if you have these in your oil it's a big problem.

  13. Damn fool talking, ignore his lame advice. His example that some cars in the 60 didn't even come with oil filters is right, they also were worn out by 100 K. My 99 Tacoma has 286,448 miles and still uses NO oil per 3,000 mile oil change. Wix filters since break in. This guy is as stupid as he sounds.

  14. If the outside can of the oil filter is made of ferromagnetic steel putting a magnet on the outside won't do very much. The steel can will act as a shield and conduct the magnetic flux between the two poles of the magnet. Internally there would only be a very weak magnetic field to attract any particles in the oil.

  15. You could describe how differently oil filters varry in micron size of thier filter element. Or some manufacturers still put magnets in thier filters.

  16. That's so funny magnets maintenance now that is funny I guess snowflakes are just something to pick on magnets come on ha ha ha ha my sides are hurting

  17. The magnetic sump plugs work, super fine sludgy paste has to be wiped of them. Have them in the motorbike too where it shares the oil with the gearbox.

  18. Unfortunately, you don't have even a trace of fact to support your claim Scotty; nothing but pure speculation and supposition here I'm afraid.
    If you want to make believers out of us, you'll have to show some "dinkum" scientific results, bud(?).
    I'm not saying you're entirely wrong – far from that; the oil filter IS designed to keep the oil clean but it has to have a balance between filtration and flow so there's a limit to what they can use as a filtration media. Logic tells us that the really fine particles will pass right through – that issue is absolutely not a debatable. It's a fact.
    The real debate is whether or not those fine particles ARE indeed harmful, to what extent and how much of an ACTUAL difference the magnets will do with respect to what size/type of magnets to use? Granted, the punishment our car engines take is not on par with the punishment of heavy engines (eg. that of mining trucks) so the layman might see similar benefits.
    I suspect the oil-filter manufacturers have already factored this aspect of filtration a long time ago and decided that the marketability of the concept wasn't economical, but with cars becoming more expensive and people keeping their cars longer, I expect that will be changing more and more(?) as time goes on.
    There are already companies like "beartrap" who have started capitalizing on this market and their documentation presents a compelling argument; being the eternal skeptic, I can't help wonder how authentic their results are. I'm hoping someone will do some real-world, side-by-side tests for us on YouTube soon.

  19. I wish I could post a photo in comments. I use a single filtermag on the oil filter of my jeep. I cut it open every oil change I do just to check the health of the engine. It does work!

  20. scotty the real questions are: IS THE OUTER CASING OF THE FILTER in the feed path before the filtration occurs or it is bathed after the oil passes through filtering media? is the magnet strong enough so the magnetic field is still present INSIDE the filter housing? you could test those instead of just talking…i bet you are right but you proved nothing… and i think the filter outer housing is after the oil passes through the filtration material so rendering the magnet completely useless because the oil is already filtered when passing there

  21. Ok my turn to chime in ! Ex British luxury car mechanic here. A magnetic drain plug in engine and gear box is a good idea, to catch those metalic critters before they could flow any further; with the potential for devastating damage. A chipped tooth from a missed gear change; if caught can definitely save the rest of the gear box. Yes agreed if metal is being shead by the motor you have problems. BUT a good idea to catch them as soon as possible. Why NOT have a magnets placed at strategic positions ?!. I cannot think why not.

  22. blablabla modern cars have magnets near the oil drain plug and/or gearbox pan by default! mercedes does that for a reason.

  23. I do believe that adding a magnet could potentially be beneficial….one reason I like having a magnetic drain plug is to capture any ferrous debris to prevent further damage. And another reason is so that I can see it when I remove the plug.
    He's right that the presence of metal indicates that you've got a problem but without the magnetic plug, you might not catch it early enough to prevent major damage.
    Scotty, an ounce of prevention…..

  24. so there is no metal in a engine …. really!!!!!!!!, and im guessing that the metal dosnt wear down and cause damage to other parts of that magical non metallic made engine..!!!!!! dont be stupid. think back to the days when u where doing Ur Toyota training, they must have been lying to you

  25. Oil filter magnets actually are a good idea Scotty just not in the way you think. They can help keep the filter media cleaner for longer since the metal particles end up sticking to the wall with the magnet instead of clogging up the filter media more which increases filter life and filtration performance. In reality it's still not that practical unless it's a super high perform car since it can filter longer and with better performance but if I had a $100,000+ car I'd change the oil every 2,000 miles anyway.

    I can also see it for someone wanting to take a 10,000 mile conventional oil filter to possibly 15,000 miles with full synthetic oil to save some money, or 2-3 5,000 mile conventional oil changes with 1 10,000 mile cheap filter and keep the same filter, or a 20,000 mile filter to two 15,000 mile full synthetic changes or hell 4-6 5,000 mile conventional oil changes because the metal particles don't clog the filter media as much. I don't really advise it anyway because a filter is $3-$9 so it's not a bank burner to me but I can see some real cheapos, misers or sadly some genuinely poor people who need every dollar to live doing this trick to spend less on filters since they can reuse them for 2-6 more times depending on the oil and filter used.

    The 20,000 mile synthetic Mobil A1 filters i use are $9 at Wally's so I'd still change it anyway. I could dare take one magnet equipped Mobil A1 filter to 30,000 miles with two 15,000 full synthetic changes if I wanted to or 6 5,000 conventional changes and I think the filter media would hold I just drive normally mostly highway, still not risky enough to try it. I would try in on a $500 beater and post the results on YouTube if I had a worthless car to experiment on.

  26. My thought is run both the less caught in the filter materials it self the better flow the filter will have for longer.
    If it has no magnet to start with I'd throw a cheep filter on with a magnit run it for 5 or 10 hours then just change the filter to a better one

  27. You may have a point but if you rebuild a motor that just ate a set of rod and main bearings and there's a possibility some of that metal didn't get cleaned out of all the oil passages ,the $15-20 for a magnet isn't a bad idea

  28. Is rust magnetic? Like from a fuel tank and passing thru in the fuel line? If you can prevent the clogging of a filter would it not work better? For the flow of either oil or gas?

  29. good video scotty but got to disagree. when I was in Auto tech school in the 80s we did several test with magnets on the filters and drain plug and oil pan and was shown to attract extra metal within the filter and where ever there was a mag.. now take into mind many oil filters are trash. back then we didn't have those cheap oil filter magnates we used very strong rare earth magnates. we had a V8 and inline 6 and a lawn mower eng we tested on.after 30 years I still use magnets…

  30. Hey Scotty, how can I add some magnets in my 2005 CTS, it has an oil filter cartridge inside an aluminum housing!!

  31. You are either delusional or ignorant. They make Youtube videos for people like you, showing the results and a thinker would see a possible clog or passing through of the smallest particles being saved on the outer layer, by a magnet, as doing exactly what it sets out to accomplish. And for a reason.
    The bigger and only question anyone should be arguing with adding magnets are the effect of the additional pressures caused where it is placed, "pushing" the oil.

  32. Scotty, Love all of your vids. However I noticed that there are magnet/s in the ATF pan.
    When changing ATF fluid I always find micro-fine ferrous material firmly attached to them.

  33. Scotty, I have been watching you for years..  However, I can recall going back 20-30 years that my Chrysler minivan had a magnet at the bottom of the transmission oil pan.  It always had metallic paste on it, which I cleaned.  Also the transmission and differentials on my cars had magnetic drain plugs..  They always caught metal shavings in the form of a fine paste..  Cant magnets at least give you an added layer of protection?

  34. I found a magnet that went through a differential, its also common to see them in a transmission, and some drain plugs have a magnet. It may be true that a magnet is not typically needed on an engine oil filter, but they are used to trap iron and steel particles in other fluids. The magnefine filter has gained some respect for its design and Allison has a magnet under the filter for the same purpose. Oil analysis identifies Fe in all fluids and people who are OCD will buy any gimmick even if its not essential. I put a filter on my transmission cooler line and put a small magnet inside the return side and there was stuff that collected on the magnet and all over the filter base, this filter system saved my transmission from destructive effects of contamination.

  35. huh?- on my 2010 fj cruiser the rear diff drain plug is magnetic and collects a finely gritty sludge that i clean – also the transfer case drain plug is magnetic as is the front diff drain plug. my tranny oil pan has 5 or six magnets attached and they are not as "sludge-y" as my diffs. so toyota engineers (all fj's are made in japan) must know something …

  36. don't produce videos without knowing what you are talking about. Your statement is far from any scientifical reasoning and understanding. I would be ashamed to broadcast your kind of content to an audience this large.

  37. Magnetic sump plugs have been around since Adam was a boy. If the engine is OK there will be nothing on it. If there is something on it the engine is coming apart. It's a warning mechanism.

    Plus paper filters are pretty good at catching fine particles, that's why they use them for air cleaners.

    Dead on the money Scotty.

  38. I've seen so many videos of magnets on filters that catch all sorts of tiny particles on them… Anything that helps…

  39. And, how do you know your oil filter is working correctly or not? I doubt one of those hf mag pans in the video would do any good but I always have a neo mag attached to the bottom of the filter and a couple on the oil pan. Until someone shows me thru independent testing that it doesn't work, I'll stick to it and I won't complain if I get another 218k mileage.

  40. My trans has magnets in the pan (factory installed), I also have an inline filter I put on the trans oil cooler line that has magnets in it. Both differentials have magnets in the filler plug (factory installed), Transfer case has magnets (factory installed), My power steering pump has magnets in it, (factory installed), Engine drain plug has a magnet (factory installed). I bought a set of rear earth magnets I swap onto every new filter when I change my oil. If FORD saw fit to put magnets in all these components, there must be good reason for it. Dontchathink Scotty?

  41. generally the advice from Scotty is pretty down to earth and good, but he missed the boat on this one … pretty much all modern engines have ferous metal components in them and those matal pieces DO wear down and put sub-micro particles in the oil … smaller than the filters are capable of filtering … and so strong magnets can indeed trap tese materials and prevent them from circulating and acting like micro-abrasives … of course, the best defense is changing your oil often … but anything that removes particulat material from your oil is a strong benefit as well …

  42. To clarify: Magnets on the DOME END of the filter really don't do anything that would actually show up in an oil analysis test. Why? the filter is full of oil under pressure for sure, but the flow of oil is greatest at the open end of the filter, that is, the oil takes the shortest path thru the filter and if you have magnets located there, they will catch visible amounts of wear metals, ferrous type, while all other wear metals will drop as a result! The oil does not travel all the way to the end of the filter media before passing thru, so long/oversize filters does not improve anything as you might think. Long narrow bar magnets along the sides of the spin-on filter close to the mounting threads does work great though!

  43. Maybe the thinking was that it would trap the metal before it got in the filter media, so let the oil flow better and make the filter last longer? Though I don't recall if the oil comes from the outside to the center of the filter, or the other way around.

  44. Scotty, the first time I STRONGLY disagree with you. I got a Toyota Tundra I use as a beater that has 236 thousand miles and doesn't burn not even an ounce of oil. I experimented by putting a quarter size rare earth magnet on the filter and later cut it open. To my surprise there was a metalic black film looked like grease stuck inside the filter in the shape of the magnet. The rest was clean. This metal could otherwise of circulated through the engine had the filter reached bypass mode. On a new GM car I suppose you would get a pound of metal. This test would be a great next video for you.

  45. It is true that your vehicle will probably run just as long (and as well) with or without putting magnets on your oil filter canister.
    But I would like to share a few things about oil filter magnets:
    First, I have run magnetic oil drain plugs for decades and there has always been a small bit of black goop built up on the drain plug magnet. This is to be expected, and catching this goop it is the reason why a magnetic drain plug is a good idea. However, when I began running magnets on the outside of my oil filter canisters, the black goop disappeared from the magnetic drain plugs. I mean it completely disappeared and there was nothing at all on the drain plug magnet. Goop gone.
    Also, many internet videos show the inside of a used oil filter canister that has been run with magnets on the outside, and you can see the pattern of magnetic particles on the inside of the can. This also confirms my first point: the filter magnets are actually catching fine ferrous particles that would have ended up in my oil pan. This means that the filter was not catching some of the iron particles! Pay attention Scotty!
    Finally, by using filter magnets and catching these particles inside the filter canister, you are keeping some of these particles out of the oil filter media and therefore prolonging the service life of your oil filter. So your oil filter can be used for more miles, and/or a longer period of time.

  46. I saw this just after watching a video of why it's really important to put magnets on your filter. And after reading many of the comments here, I'm beginning to suspect that this a highly controversial issue that nobody can agree upon. 😂

    When I was in school 5 years ago, I brought up the idea of putting a magnet on either the filter or oil pan to my instructor, since I heard about it somewhere else. He said "sounds like a good idea at first, but what if that magnet falls off? Then all that metal junk gets circulated up inside your engine and can cause damage. A halfway decent oil filter works just fine and that's what it's there for."

  47. Scotty may be correct. If you put a very strong magnet on the bottom of your filter it could affect the bypass valve.

  48. Lots of engine components that wear are non magnetic metal anyway. Especially in newer lighter weight engines.

  49. Generally good information, but I am very familiar with oil filters and the way they work. When cold and when the oil is old it gets highly viscous. For this reason oil filters have spring operated bypass valves. Much of the oil your engine uses at startup does not go through the filter. It just wouldn't flow fast enough. It pushes a bypass valve open and flows around the filter. When this happens particles can circulate through the engine. Many of these particles are metallic and can cause additional wear. The filter magnet could trap these particles that would otherwise bypass the filter and it can trap ferrous particles that are fine enough to pass through the filter. It would have no effect on non ferrous metals. I would say these devices cant hurt and may slightly reduce wear. OEMs have been using magnets in differential pans for a long time. Its not completely unsupported technology. Just dont pay much for one of these devices and realize the effect is likely to be minimal and not easy to confirm. Dont waste money on fuel line magnets. They are definitely snake oil.

  50. Working on wind turbines there’s a large inline oil filter installed used to gather gear box metal grind particles collected by magnetic rods along with the filter, we would take a sample of oil and send it to engineers to inspect degradation in the gear box.
    That’s the only use I seen for magnetic filters.

  51. I disagree. The magnets I had on my Thruxton with K&N oil filter would collect fine almost powder like lines of metallic wear particles. The oil pan drain plug magnets in my granddaughters Honda Accord picked up some larger pieces of metal that could have really done some damage. i also take the filters apart and do not find these metallic pieces in them
    very often. I use them and will continue to do so. .if you send your oil in to have it analyzed they can tell you the metal content of the oil -in percent not chunks! I will continue my magnetic attraction to my oil !!

  52. What about magnetic drain plugs for transmission fluid? I saw a guy on YouTube with one of those & it caught a bunch of metal shavings. He also said that the majority of transmission wear occours within the first 10,000 miles.

  53. They’ve actually open a filter after magnets and you do have residue where the magnets where.
    When the filter goes into Bypass such as start up. The filter is only doing have the job. And any filtration that the filter captured can get knocked out the media and back into oil. Magnets do work and I insist anyone who wonders go look at videos here on YouTube of filters opened after using magnets. The residue can be seen built up on filter casing.

  54. I wonder if that was some good old fish oil he was peddling…might have been beneficial after all. You should get a syringe, draw some out and get that oil (if original) analyzed. If its fish oil Scotty your relative would be rich today! Either way some fishy business going on…thanks for stopping me from magnet fishing on my oil filter.

  55. Scotty, this is the FIRST (and I hope the ONLY) time I completely disagree. NO oil filter filers at 99%. That is a LIE (by the filter manufacturer). If one did, hardly any oil would flow through it. I have one of those half round filter magnets. It DOES work. I've cut open filters without removing the magnet. That metallic "paste" contains minute particles of steel that are way too small for the filter to remove. Even the best filters (Baldwin, Mobil 1 or AMSOIL) can only filter down to about 10 microns at best, no matter what any manufacturer claims.

  56. You also seem to forget that those particles have to pass through the oil pump before they hit the filter. Almost all Allison transmissions and most aircraft engines use magnets as well. In the end, they don't hurt anything. Also when the oil is cold, the bypass valve in the oil filter will open to prevent oil starvation . When that happens, the oil goes around the filter into the engine components.

  57. Dang even some of scotty's relatives from days gone by were snake oil salesmen. Welp Scotty you've since right that wrong with the help you're providing out here lol

  58. Well of course if you put a magnet on the outside of a oil filter it'll catch metal particles, that oil hasn't even been filtered yet. Oil travels from the outside of the filter media towards the inside.

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