A thought on magnets, and UOA's...

Not open for further replies.
Jun 8, 2004
Lancaster, Pa
I have the small magnets mentioned in other posts and have a question based on their use. If you were to install say two magnets on the oil filter and they were to "catch" debri, while that would be a good thing, when you do a UOA would your indications of wear metal be lower thus providing an analysis that does not indicate how well your oil or engine is actually performing??
I suppose that COULD skew the results of UOA. Good Point, plus who knows if those magnets really catch anything at all?
There's a decent amount of debate on this. You obviously don't attact all the Fe that's in the oil, even though it would be reasonable to assume that all of the oil will pass by the magnet at one point or another. The consensus among the stratus dwellers is that, below a certain size, particles can't be drawn out of solution. I forget the term for this particle level bouyancy unit.

But they do attract material and they can't hurt. What's uncertain is whether they mask Fe levels in UOA ..but I imagine if you see a recurring beard on your magnet ..that you won't need to be
to realize that you've got issues.
I wouldn't see how it would hurt as the wear metals are not magnetic. About the only iron particles you should get would be from casting remains in an iron block (barring catastrophic failure which should not need a UOA).

Correct me if I'm wrong.

Iron particulates from the cylinder walls (or from iron or steel cylinder liners in aluminum block engines) would constitute a magnetic wear metal. Chrome plating, which is also highly magnetic*, can be scuffed off piston rings. (I believe the scuffed chromium particulates would also fit the definition of a magnetic wear metal?
) Chromium's not only more highly magnetic than iron, it's fundementally harder - which translates to more abrasive in randomly shaped particulates grinding against precision bearing surfaces. Definitely not a substance you'd want bobbing around in the oil if it's too small to be trapped by the filter. EMBRACE & CHERISH the neodymium magnet from an old hard drive head actuater! It's a loyal, re-usable, inexpensive friend for your engine.

*There's a reason professional broadcast video tape used chromium dioxide as its magnetic medium instead of ferric oxide - the inherently increased magnetic properties of chromium allowed higher frequency bandwidth which in video applications meant increased picture detail response before everything went to digital recording and retrieval.

[ May 30, 2005, 10:38 PM: Message edited by: Ray H ]
Just an observation and a question. I'm not against magnets; I have a Magnafine filter on my tranny

Has anyone ever taken a screwdriver and put it on a magnet for a little bit? After this, the screwdriver becomes slightly magnetized

Is there any chance that some of these new "magnetized" metal bits could come loose from the magnet and then stick to metal in the engine?

This is just a question that I have always had.

I wouldn't worry about magnetic debris.
Magnets have been used in transmissions, xcases, front/rear-ends....for years.
If the magnet catches it, it'll stay put.
Brian, I have had the same concern. I really don't know if a magnetized particle would do anymore damage that it's non-magnetized counterpart.
I have a magnetic drain plug on my saturn and it picks up quite a bit of metal... I haven't done any UOA but i think it would skew results.
Well, Ray, it's hard to tell between wear causing particles and wear caused particles. The magnet sure doesn't know. What we need to see how much it alters a UOA is to do a PC before and after a magnet is installed.
Yeah . . . Using a magnet does skew the results. That's the whole point - to magnetically isolate little ferrous and chromic nasties small enough to traverse the filter medium so they're out of the loop in further contributing to engine wear. Here's a further brainstorm: the use of motor oil also skews the results . . .
Not open for further replies.