I have several large rare earth magnets. I was thinking about putting one on the bottom of my oil filter to capture shavings.
Can anyone think of reasons why I shouldn't?
I have put them on both my transmission and oil pans, but it seemed to me that it would be better to capture at the filter.

 

It probably won't do any good. The case of the filter is steel and the magnetism will be in the steel and won't penetrate. If the case were aluminum and you had to tape or glue the magnet to it then it would trap ferrous particles. If the magnet were small enough you might drop it inside the filter but then you'd have a heck of a messy time getting it out again. You want to make sure it didn't plug anything up or get sucked into the engine or pump.

Check the drain plug and see if it's magnetic. Get one if it isn't.

Edwin

 

Originally posted by edwinsmith
It probably won't do any good. The case of the filter is steel and the magnetism will be in the steel and won't penetrate.

Edwin




Try it sometime with a steel can, like a coffee can, for instance. It does "penetrate". I can't say if it will capture particles that the filter will pass.

Wetspirit

 

I do it. I have no idea if it actually does any good, but it makes me feel better.

 

I don't think I would put it in the filter, especially the center hole. That goes straight into the engine.

 

I've had one of these http://www.motrlube.com/catalog/item/1183627/687922.htm on my truck for several years and it does make a difference.
I inherited the $40 device but would never pay the price they are asking for it though. All it is is two rows of 1/2" diameter magnets spaced about an inch apart inside a plastic pad. The magnets are very strong, it's impossible to lift the pad off a metal workbench, you have to slide it.
When I dissected a used filter it was very obvious what it did, there were black areas at each magnet. Whether these particles are too small to cause damage I don't know. My feeling is if the magnet catches anything too big it's already too late, you have a major engine problem.

My bottom line is if you need a place to stick a magnet the side of your filter is a good place, I wouldn't go out and buy any though. I've heard of guys going to the places that make stick on car door signs and getting flexible strip magnets for their oil filter for free, they're just scraps.

My filter looked exactly like these

 

Next time you change your oil let it set in the drain pan for a hour or so then gently pour off all but an inch or so. then take the magnets you have and rub it around the bottom of the oil pan. Ya might be surprised what you see. Ive been a few times, not from my CTD, but other engines, diffs and trans oils.

 

Thanks for the responses!

These magnets will smash the crp outta your fingers if your not careful. They WILL go through the side of a steel filter case. LOL

Im gonna put one on my filter.

 

I normally just use a strong flat magnet on the oil pan, right by the drain plug. I pop it off before draining then put it back when I'm done. For the $.75 or so invested I don't think I can go wrong.

FWIW, my transfer case was puking out horrible amounts of metal after the first oil change. After 6k miles the bright red oil turned into a pukish grey, since I replaced it with a 75w90 and after driving another 8k on it with a magnet stuck to the case it appears perfectly clean.

 

I wouldn't put those rare earth magnets on the oil filter if I were you. I too have bought those magnets for oil filter purpose but rare earth magnets are sensitive to heat and lost their magnetic force when the temp too high. I have two, the magnet I leave in the house still have magnetic force but the other magnet I put in my car lost all it magnetic force and dont work any more.

 

Perhaps it was just applicable to your manufacturer? Mine have been tagging along on transmissions, transfer cases, rear ends, and oil pans for years on several of my vehicles and still seem as strong as the day I put them on. I haven't tried putting them on filters, instead I place it on the lowest point I can on the oil sump itself in hopes of it taking the metal out of circulation, but still easy to drain with an oil change.

 

Unless you have magnetized your sump pan.

 

Valid point, I haven't noticed it doing that yet. I try to keep it by the drain plug so if it does try sticking a little the flow out should help move it along. Or at least that is the theory behind it.

 

Even if the pan became magnetized it wouldn't make much difference as long as the stuff it collected stayed put.

 

I use magnets from damaged harddrives and place on the oil filter.
Another option is drain plugs with a magnetic tip.

MikeyB