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Mon Oct 11, 2021 9:56 am

I replaced the oem magnetic oil drain plug for an oil temp sensor so I lost the magnetic plug.
Thinking about moving the location of the temp sensor to get the magnetic plug back, but haven't done it yet.

I did find this magnetic patch to place on the outside of the regular oil filter.
I like it better then the oem plug because the oem plug waits for the engine to stop and letting the oil settle to attract the metal. This is acting on the oil flowing through the oil filter in real time.
Plus you can move it onto a new filter when you change them.

So i ordered one and leaving it up to you for your preferences.

https://www.beartrapfilters.com/light-trucks-suvs-1

They have a "how it works" video on the home page, but it's using a glass see through bottle which is okay for viewing. I was more concerned about real life and the metal can of the filter absorbing the magnetism and not attracting the metal as it does in the glass bottle.

This cut away of a filter shows that it does work!

30 bucks on Amazon, same price as the website.
https://www.amazon.com/gp/product/B07FM9JHSD/ref=ppx_yo_dt_b_asin_title_o00_s00?ie=UTF8&psc=1

Mon Oct 11, 2021 10:21 am

Careful, you're going to give SODO nightmares since it's one more thing that can collect bits of metal with a magnet on the Vanagon... :wink: :wink:

Mon Oct 11, 2021 10:39 am

You can do this same thing by just sticking rare earth magnets to the filter. Amazon has them cheap, no need to overpay for a logo.

Mon Oct 11, 2021 10:43 am

This seems like an old idea that I'd heard of decades ago and forgot about. May have been around since the 30s of 40s?
Seems simple, inexpensive and brilliant. Can anyone think of a downside?

Here's a method using $3 of super-strong magnets (10 for $10) instead of $30 patch. Caution: magnets like these can be dangerously strong.

Jim Davis

Mon Oct 11, 2021 10:45 am

Fiddlestyx wrote: You can do this same thing by just sticking rare earth magnets to the filter. Amazon has them cheap, no need to overpay for a logo.

Yeah I've got some rare earth magnets for window screens and thought about it then thought about getting them off! 🤣
However, common sense is trying to cancel the order now!

Mon Oct 11, 2021 3:45 pm

So let me get this strait... you want to attach a magnet to the filter so that the metal is attracted to the outer skin of the filter instead of being trapped in the filter material? Why? That's what the filter is for. The magnet on the drain plug will catch chunks of metal that are sloshing around in the bottom of the case before they get drawn up into the pump and filter.

Hans

Mon Oct 11, 2021 3:53 pm

where a magnet is useful is to attach to the bottom of the gas tank... keeps rust particles away from the screen. keep it there permanently, don't remove it or the particles are freed.

Tue Oct 12, 2021 4:22 am

hdenter wrote: So let me get this strait... you want to attach a magnet to the filter so that the metal is attracted to the outer skin of the filter instead of being trapped in the filter material? Why? That's what the filter is for. The magnet on the drain plug will catch chunks of metal that are sloshing around in the bottom of the case before they get drawn up into the pump and filter.

Hans

Your question does raise the obvious point and a good one.

What is the oil flow path through a filter? I don't have oil flow diagram of the engine in front of me to be able to tell.

1.) Does it come in through the center pipe and then through the filtering medium to exit out the small holes around the top?
2.) Or does it come in through the small holes to exit up through the center?

If it is #1 then that filter medium did not stop the small fine metal particles otherwise they would not be there to get stuck on the magnet.

If the flow is #2 then you could say that the magnets are keeping the metal particles off of the filter medium so it stays cleaner longer to do what exactly - keep the metal particles from passing through? That's a Catch 22.

Picturing that rubber flap valve underneath the small outer holes I do not think it is the #1 flow direction in through the center. I think it would have to be this direction #2 as it gives the maximum surface area to be used as the filtering surface.

Now I'm wondering what size the pores are in the filtering medium just out of curiousity.
On the boats where I make fresh water out of the salt water the pores on the filter are so fine that they not only block the salt particles they block all the minerals as well. They have to use a high pressure pump to force the water through the filtering medium and it starts working above 400 psi, but we normally have it set to 800 psi.

Tue Oct 12, 2021 4:25 am

DanHoug wrote: where a magnet is useful is to attach to the bottom of the gas tank... keeps rust particles away from the screen. keep it there permanently, don't remove it or the particles are freed.

That's a good idea.

Tue Oct 12, 2021 4:43 am

'twasn't my idea... a US based company, TOMCO, marketed 'tank magnets' for years among their fuel injection offerings and carb rebuild kits.
http://www.tomco-inc.com/

Tue Oct 12, 2021 4:53 am

Just use the ones on your fuel lines polarizing your gas molecules for better mileage before your oil change.

Tue Oct 12, 2021 5:48 am

Abscate wrote: Just use the ones on your fuel lines polarizing your gas molecules for better mileage before your oil change.

oh Lol...There is a "Grander Device" which is a glass bottle filled with a water from a source in Austria I think. The bottle is located inside a stainless steel contsiner so that you can flow your house water around the glass bottle. The water is changed by the water inside the glass bottle so that it tastes better. It cost $3940.00 + $29.00 shipping for the "W10" model.
I just installed one onboard a boat. It may actually work, but I did not pay for it. 🤔

Tue Oct 12, 2021 9:18 am

Steve M. wrote: hdenter wrote: So let me get this strait... you want to attach a magnet to the filter so that the metal is attracted to the outer skin of the filter instead of being trapped in the filter material? Why? That's what the filter is for. The magnet on the drain plug will catch chunks of metal that are sloshing around in the bottom of the case before they get drawn up into the pump and filter.

Hans

Your question does raise the obvious point and a good one.

What is the oil flow path through a filter? I don't have oil flow diagram of the engine in front of me to be able to tell.

1.) Does it come in through the center pipe and then through the filtering medium to exit out the small holes around the top?
2.) Or does it come in through the small holes to exit up through the center?<snip>

Here's an animated video from WIX showing oil filter flow. At about 1:40, it shows the oil flows into the filter around the perimeter, through the filter media, and then out through the center.

https://www.youtube.com/watch?v=dJ7ChsZCmJo

I suppose the benefits of magnets would be that they could theoretically catch particles too small to otherwise be trapped by the filter and the they would still be effective during instances when the bypass valve is open.

Jim Davis

Tue Oct 12, 2021 9:23 am

hdenter wrote: So let me get this strait... you want to attach a magnet to the filter so that the metal is attracted to the outer skin of the filter instead of being trapped in the filter material? Why? That's what the filter is for.

Hans

x2

i guess it does a good job of visualizing whats in the filter by clumping it together at the magnet?...

Tue Oct 12, 2021 10:49 am

There’s something to be said for epoxying the magnets on so nobody rempves them, loosing the pile on the inside. (On the gas tank too).

The magnet is pulling the metallic bits out of the oil each time the oil is “still”.
The magnet cannot pull them out of moving oil. Except big particles. Which you won’t ever have in an engine.
When the particles fall downward by gravity, the magnetic pull captures the nearby ones that bend towards the magnet each night and they layer up.

Of these particles:
some would get caught in the filter media;
the smaller ones go right thru and then later have a chance to get caught by the magnets some other night.
And many (most) others don’t get caught.

There is nothing in the engine that resembles the bearings and gear face pressures in the gearbox.
Especially in an over-engined gearbox; where every gear face, shaft, bearing is too small for the engines output (within the engineered parameters, expected lifetime etc)
Everthing in the engine is low-pressure over larger areas, and the particles are suspended in a thicker oil film, and higher clearances that tolerate the particle size.
Its well-tested over the years.

Did you ever wonder why they don’t use ball bearings on the connecting rods? How about roller bearings?
It’s because they would not survive the point-loading in the inevitable contamination.
And the oil required would be too thick for the bearing speeds.
You’d have to change the oil way too often just to save the bearings.

This is a rich subject.
It would be great if a genuine ‘bearings engineer’ or ‘lubrication engineer’ was on the forum.

Tue Oct 12, 2021 11:01 am

to continue beating the drum of oil analysis...

how many of the items in the below list (as a random example from my still-breaking-in-TDI) are magnetic.
not many.

also if you want to really nerd out on oil/filters/UOA/etc check out https://bobistheoilguy.com/forums/threads

there are lubrication engineers on there! and a generally overwhelming amount of deep dives into all things oil.

random topics on oil filter magnets
https://bobistheoilguy.com/forums/threads/oil-filter-magnets.175590/

https://bobistheoilguy.com/forums/threads/question-on-oil-filter-magnets.295011/

some of those threads do bring up an interesting point regarding the magnets possibly interfering with the bypass valve.

Tue Oct 12, 2021 12:13 pm

valvecovergasket wrote: how many of the items in the below list (as a random example from my still-breaking-in-TDI) are magnetic.
not many.

But the ones that are, you don't want floating around. $30 for a magnet is pretty pricey. I've discussed these with a friend in the past. I guess the way to look at is, for $30 will it give you a bit more life to your motor over 50k miles? Does it matter if its 5k more miles? $30 is surely worth driving 5k miles, but engines generally don't fail catastrophically and it just means you get poorer performance at the end. So will you really notice?

For $5 I would absolutely buy it. But does that even make sense? If I agree that it is useful for $5, why not run it for $30? What is another $25 in terms of the cost of replacing a motor?

Wed Oct 13, 2021 8:32 am

I have the sandwich magnetic filter called Magnafilter.Seems like a nice product.

Wed Oct 13, 2021 8:34 am

4Gears4Tires wrote:
For $5 I would absolutely buy it. But does that even make sense? If I agree that it is useful for $5, why not run it for $30? What is another $25 in terms of the cost of replacing a motor?

i guess to put it another way - this seems like a really clever solution in search of a problem.

Wed Oct 13, 2021 10:45 am

We already know magnets in the oil are good. We use them in the engine oil drain already. I guess I would like to see how much more effective this is on the filter than solely having the drain magnet. My caveman brain says mo' magnets mo' betta'.