Engine Oil Filter Magnets?

I am leery of filter magnets because of the different flow patterns in an oil filter. If cold oil hits captured iron particles from the day before and there is a bypass event, not sure that would be a good situation. Block bypass systems would be ok and drain plug magnets where the flow is not pressurized. Sure the magnets show captured iron after cutting open a used filter. What does that mean? It means when the engine was stopped, probably hot, the iron particles were captured or recaptured by the magnet. There is no way to know if those particles haven't been through the engine several time before. They can go through the bypass and be recaptured again when the oil is hotter and the bypass is closed. There they are on the magnet.

Holding particles in case of a bypass event is a benefit of the mag not a downside. The other choice is nothing stops them.

The theory they capture only current particles traveling at a given moment on shutdown isn't how they work.

If this were the case one would find continuous particles being caught if you changed filters mid OCI.
This is not what you find.

You can try this experiment yourself -

What you find is that the particles they catch are indeed built up over time and held.

Run a mag for 80% of an OCI and look whats stuck on the can,
Toss it, attach a fresh filter and put the mag back on and drive for a thousand or more miles or and cut it open - little to nothing is on there.

If the "wash away and re-catch" theory had merit you'd find a continuous stream of debris on the mag filter after filter. You wont.
 
HUGE!!!!!!!!! lol

It wont be huge but keeping particles out of your titans timing chain is never a bad idea.
A good filter, sane OCI's and a mag are a solid foundation.

I run them on my titan.
 
I’ve personally seen tiny but high end and expensive magnetic drain plugs catch a good amount of “iron sludge” on what are essentially aluminum engines with UOA reports showing iron in the 2-3ppm range after 3k miles with a regular OEM oil filter.

What I want to see is a magnet placed directly AFTER the oil filter and see what it catches after say… 10k miles because we have no way of knowing if the oil filter would have caught that fine “dust” or not.

I don’t understand why this hasn’t been proven yet.

Does anyone know if high end super expensive engines incorporate any magnetic filtration in their Lubrication system?
 
I am leery of filter magnets because of the different flow patterns in an oil filter. If cold oil hits captured iron particles from the day before and there is a bypass event, not sure that would be a good situation. Block bypass systems would be ok and drain plug magnets where the flow is not pressurized. Sure the magnets show captured iron after cutting open a used filter. What does that mean? It means when the engine was stopped, probably hot, the iron particles were captured or recaptured by the magnet. There is no way to know if those particles haven't been through the engine several time before. They can go through the bypass and be recaptured again when the oil is hotter and the bypass is closed. There they are on the magnet.
It couldn't be any worse than an oil filter with a dome end bypass.
 
I've run a magnetic drain plug since day 1 and there was always a little blob of black goop on the tip when doing an oil change. Of course I would clean that off every time. When I started using a few cheap rare earth magnets on the canister filters, suddenly there was no more black goop on the magnetic drain plug, I mean none. Plus I cut open one of the canister filters and found patterns on the inside where the magnets were stuck. This is on a vehicle with 60,000 miles at the time (now has 173,000 miles). So I know for sure filter magnets do catch some particles, but will this significantly increase the lifespan of my engine? Who knows.
 
Used on my 4.0L V6 Tacoma. Magnetic plug at 5,000 miles after initial break-in. Layer about 2 mm thick.

1642110846608.png



Magnetic plug at 50,000 miles after totally broken in. Layer barely detectable.
Oil changes typically around 5K miles.

1642110759873.png
 
What I want to see is a magnet placed directly AFTER the oil filter and see what it catches after say… 10k miles because we have no way of knowing if the oil filter would have caught that fine “dust” or not.
I don’t understand why this hasn’t been proven yet.

Problem is a magnet works better where the fluid stream is slow.
It just takes some time for the magnet to attract Fe particles.
Oil channels and lines are small diameter and as a result the flow
speed is rather high. That said, where exactly upstream would you
actually place a magnet? Drain plug and filter are best accessible,
that's why they're used.
.
.
 
I agr
I will be buying a magnetic oil drain plug for my engine oil. I bet if I also bought FilterMag from filtermag.com I bet that it would really make a huge difference!
I agree lawnguy. I have used Filtermags for years and a Dimple magnetic oil drain plug. Now with 625,000 miles on my 1993 Civic, I
feel that removing iron particles has made a difference.
 
I am leery of filter magnets because of the different flow patterns in an oil filter. If cold oil hits captured iron particles from the day before and there is a bypass event, not sure that would be a good situation. Block bypass systems would be ok and drain plug magnets where the flow is not pressurized. Sure the magnets show captured iron after cutting open a used filter. What does that mean? It means when the engine was stopped, probably hot, the iron particles were captured or recaptured by the magnet. There is no way to know if those particles haven't been through the engine several time before. They can go through the bypass and be recaptured again when the oil is hotter and the bypass is closed. There they are on the magnet.

What you're saying is that potentially the fine iron particles you see on a filter magnet were only the last particles caught the last time you shut the engine off, which would be those particles in close proximity to the magnet inside the tiny volume of oil in the filter.

Given the amount of magnetic sludge you see in some cut apart filters with magnetics, there's have to be a YUGE amount of magnetic particles circulating in your engine oil.

I don't think that is the case.

On the other hand, I'd be really surprised if the amount of particles being caught had a substantial impact on engine life. In most cases a normally well maintained engine will outlast the useful life of the rest of the car. Most engines really have gotten that good over the last couple of decades.
 
imho, any sudden oil pressure increase may wash off and send a blob of metal shavings into the flow and if bypass valve is open at that time due to high oil pressure... hmmm
 
imho, any sudden oil pressure increase may wash off and send a blob of metal shavings into the flow and if bypass valve is open at that time due to high oil pressure... hmmm
No worries about that with a magnetic drain plug.
 
imho, any sudden oil pressure increase may wash off and send a blob of metal shavings into the flow and if bypass valve is open at that time due to high oil pressure... hmmm

So in the case of a bypass event you prefer zero protection vs some protection.
 
Pressure is irrelevant. Flow speed would matter.
True. It might be possible for the oil flow to dislodge captured material on a magnet located on the filter if the engine was revved up pretty high. It would also depend on how strong the magnet was, and how much built up material was on the magnetic area.
 
Can anyone provide any empirical data that oil filter magnets do anything besides just stick to the filter?

A lot of newer cars use a canister type setup so filter magnets are irrelevant.
 
I will be buying a magnetic oil drain plug for my engine oil. I bet if I also bought FilterMag from filtermag.com I bet that it would really make a huge difference!
Can anyone provide any empirical data that oil filter magnets do anything besides just stick to the filter?
A lot of newer cars use a canister type setup so filter magnets are irrelevant.
I started with just a magnetic drain plug, there was always a small blob of black goop on it every time I changed the oil (normal). When I started putting rare earth magnets on the oil filter canister in addition to the magnetic drain plug, suddenly the magnetic drain plug had no more goop, I mean it just disappeared. This tells me that the filter magnets are definitely doing something. Also I would suggest doing *either* the magnets on the oil filter *or* the magnetic drain plug, not both... unless you really really want to.
 
^^^ Yep, get a good magnetic drain plug if you have a cartridge filter.
 
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