Tiny metal particles suspended in oil?

[rustypigeon]

Can you see tiny metal particles suspended in your oil? Two days ago I changed the oil in my Toyota Pickup (199,000 miles). I don't drive it much anymore, but I like to change the oil every 12 months. In that time I only drove it 1600 miles. When I looked at the oil under bright light, I could see tiny metal particles suspended in the oil. I always thought the filter would have trapped any particles that were big enough to see. Keep in mind these particles were very small and someone who needed reading glasses probably would probably not have been able to see them. It made me a bit nervous, so I sent out a sample to Blackstone today.

This morning I was changing the oil in my wife's Highlander (165,000 miles). I made sure to wipe the drain pan out real good so I could check for particles in her oil. Sure enough I noticed tiny particles floating in her oil as well. I could see them easier when I did my truck oil since it only had 1600 miles on the oil and was cleaner. Her oil had 5000 miles on it, yet I could see plenty of particles.

I have been using OEM Toyota and Denso branded filters on these vehicles. Both filters have a reputation for flow over filtration. I always take a look at my oil when it is drained, I just can't believe I never noticed the particles before. They are not obvious like the particles that come out of axles and transmissions. You have to really look close under a bright light, but they were easily seen when specifically looking for them.

 

[DB_Cooper]

I've seen those from time to time. Looks like metal..but it is not. I had a shared sump motorcycle engine that looked like it was throwing off metal, as seen in the bright sunlight in the oil dump pan.

I did a complete disassembly of the engine and there was nothing wrong anywhere.

My best guess is they may be some aerification or maybe just the additives..don't know.

 

[demarpaint]

Get a UOA, see if there is anything out of the ordinary in the report. That will hopefully eliminate all the guessing.

 

[ls973800]

Put some of the oil between your fingers and rub. If it is metal,it will feel gritty. If it's just air it will feel slippery.

 

[Kestas]

30 micron particles are easy to see. I wouldn't be surprised if you were seeing 10 micron particles or smaller. You have good eyes.

 

[JimPghPA]

Drop a strong magnet into that used oil and see if the small (metal?) particles attach to the magnet.

 

[Ihatetochangeoil]

Originally Posted By: Kestas
30 micron particles are easy to see. I wouldn't be surprised if you were seeing 10 micron particles or smaller. You have good eyes.


The limit of human visibility is 40-45 microns. http://www.machinerylubrication.com/t/MLT1-2012-07-04

A human hair is about 70 microns. https://www.bing.com/images/search?q=hum...lay&first=1

I call Bee S. You can't see 10 micron particles.

 

[rustypigeon]

Originally Posted By: Ihatetochangeoil

The limit of human visibility is 40-45 microns. http://www.machinerylubrication.com/t/MLT1-2012-07-04

I call Bee S. You can't see 10 micron particles.


According to this website, some people can...
http://www.ctgclean.com/tech-blog/2011/08/is-it-clean-introduction-to-particles-microns/

I don't know if I personally can see something 10 microns, but 25 microns is .001". If set my micrometer to .001", I can easily see the air gap. I think most people would be able to see a .001" particle, especially if it was reflecting light and had a dark background, such as metal particles in oil.

 

[901Memphis]

I have had them in my Buick drain pan, they were gold and every time I saw them my copper in the UOA was above 30 ppm. I know they aren't iron because those are inside my filter mag'd Ultra filter

 

[BrocLuno]

The metallic sheen that you sometimes see swirling in an oil drain is usually aluminum. It won't attach to a magnet. Sometimes it's bearing metal, but most often it's piston skirt material...

I'd be changing filter brands - Napa Gold would be my first test filter to see if it happens again... Especially on your wife's car ...

 

[zeng]

Originally Posted By: ls973800
Put some of the oil between your fingers and rub. If it is metal,it will feel gritty. If it's just air it will feel slippery.

+1

 

[rustypigeon]

Oil report came back. Lead was 25ppm. All other wear metals were good. Insolubles were .1%.

I did an oil pressure check and a leakdown test as well today. Oil pressure on a hot engine was 18psi at idle and 60psi at 3000rpm. Toyota specs are >4.3psi at idle and 26-71psi at 3000rpm.

Leakdown was as follows...
1- 13.3%
2- 16.6%
3- 12.2%
4- 10.0%

Numbers are not that bad for an engine with 200,000 miles on it. I just need to figure out why the lead was a bit elevated, yet non of the other wear metals were.

 

[kschachn]

Originally Posted By: rustypigeon
Numbers are not that bad for an engine with 200,000 miles on it. I just need to figure out why the lead was a bit elevated, yet non of the other wear metals were.


Remember too that if those are metal particles that you see, it is quite likely they are too large to show up on a UOA given the upper bound of particle size detectable by ICP or AA.

 

[rustypigeon]

Originally Posted By: kschachn
Originally Posted By: rustypigeon
Numbers are not that bad for an engine with 200,000 miles on it. I just need to figure out why the lead was a bit elevated, yet non of the other wear metals were.


Remember too that if those are metal particles that you see, it is quite likely they are too large to show up on a UOA given the upper bound of particle size detectable by ICP or AA.


Good point. I am thinking of chaining the filter to a Fram Ultra instead of the OEM Toyota to see if the particles are still visible. What filters are you using in your Toyotas?

 

[kschachn]

Originally Posted By: rustypigeon
What filters are you using in your Toyotas?


Same as you, Toyota OEM or in the past Denso First Time FIt. The new Denso ones are made in China so I've gone back to actual Toyota ones.

I'll go out on a limb and speculate that the particles you see are either entrained air or nothing to worry about. But that's just a guess as I've never looked at the oil to be honest. All I ever look at that way is the differential oil from my BMW.

 

[rustypigeon]

Originally Posted By: kschachn
Originally Posted By: rustypigeon
What filters are you using in your Toyotas?


Same as you, Toyota OEM or in the past Denso First Time FIt. The new Denso ones are made in China so I've gone back to actual Toyota ones.

I'll go out on a limb and speculate that the particles you see are either entrained air or nothing to worry about. But that's just a guess as I've never looked at the oil to be honest. All I ever look at that way is the differential oil from my BMW.


I was using Denso as well until they went to China. I have been buying Toyota filters by the case on Ebay since then. If you have been using Toyota/Denso for over 2-3 hundred thousand miles with no lubrication related issues, that is good enough for me to continue using them.

 

[kschachn]

If I really was worried those were possibly metal particles I'd probably try and find a lab that would do an acid digestion on the sample prior to analysis.