High silicon content in oil

[clandr1]

Hi everyone,

I've sent four oil samples to Blackstone Labs over the last 3 years, and each time my silicon readings have been higher than universal averages (see bottom row of the attached picture). The techs at BL have suggested checking the air intake system for cracks or leaks, implying that dirt and debris may be getting into the system downstream of my air filter. I've looked, but haven't found anywhere that appears to be leaking.

Have any of you had similar issues you resolved, or do you know of any common failures points on the air intake system I can target?

Thanks!

 

[OneofFew]

They assume the silicone is from unfiltered air entering the system. This may not be the case. Silicone can get in through filters, come from filters themselves or come from silicone sealants and anti-seize lube. I would replace the air filter if it is at all questionable. check your maf screen for dirt and debris. Of course check for intake leaks and vacuum leaks.

 

[OneofFew]

Also I see your silicone levels were on the rise, but then dropped. What changed?

 

[clandr1]

They assume the silicone is from unfiltered air entering the system. This may not be the case. Silicone can get in through filters, come from filters themselves or come from silicone sealants and anti-seize lube. I would replace the air filter if it is at all questionable. check your maf screen for dirt and debris. Of course check for intake leaks and vacuum leaks.

Good call out. I put an AC Delco filter in a couple years back, perhaps it's time for a new one.

Also I see your silicone levels were on the rise, but then dropped. What changed?

The lead content (to me) seems to be the obvious culprit. It seems to correlate with the rise/fall of silicon. I had low oil pressure in December 2017 to the point where I could hear tapping/knocking. I quickly resolved it (oil tube pickup o-ring needed to be replaced) and was happy to see my lead levels had decreased at the next oil analysis/oil change interval. Maybe the additional lead content was causing abrasion with silicon o-rings and gaskets?

 

[OneofFew]

The faulty o ring itself may have been the source for some of the silicone. I would change your air filter like you said and wait for the next oil analysis to re-assess.

 

[CountryBoy19]

Could certain motor oils have silicon in them from the beginning?

 

[clandr1]

Could certain motor oils have silicon in them from the beginning?

You know, I hadn't thought of that. A quick Google search found this page:

http://www.pqiamerica.com/March2013PCMO/mobil1.htm

If I'm reading the chart right, Mobil 1 has 8ppm of silicon content. If you deduce that from my oil's reading, I'm well within range. Let me know if I'm misunderstanding the chart at the link.

 

[OneofFew]

You know, I hadn't thought of that. A quick Google search found this page:

http://www.pqiamerica.com/March2013PCMO/mobil1.htm

If I'm reading the chart right, Mobil 1 has 8ppm of silicon content. If you deduce that from my oil's reading, I'm well within range. Let me know if I'm misunderstanding the chart at the link.

It don't work like that. the inherent substances in the fresh oil are calculated in.

 

[Matahoe]

Blackstone told me that high levels of silicon is from an internal coolant leak mixing with the oil. Perhaps at some point someone put silicate coolant in the radiator and it's mixed in with whatever you have in there now. Either that or you go Baja racing and suckin in that sand??

 

[iamdub]

Most OEM crank and rod bearings contain a layer of aluminum and silicone. Let's hope the silicone they found was from other sources.

 

[SnowDrifter]

Not sure it's from coolant as potassium is low

3 causes for high silicon:

1. Unfiltered air getting into the engine. Vac leak, dirty filter, ****** filter
2. Any recent work done that would put RTV in contact with the oil
3. Silicon is an additive in many oils

 

[SnowDrifter]

Most OEM crank and rod bearings contain a layer of aluminum and silicone. Let's hope the silicone they found was from other sources.

Chicken or the egg. Silicon as a function of unfiltered air will cause high bearing wear too

 

[SnowDrifter]

Also: Quick peeve. It's silicon, not silicone. He isn't running a ***** in his crankcase

 

[Matahoe]

This is what Blackstone sent me. I found a sweet condensate under my oil cap and my coolant level was slowly going down. I quote...

"MATT: You suspected coolant to be an issue, and that's definitely the case. We found high amounts of potassium, silicon, and sodium which show coolant contamination.

Silicon could also be abrasive dirt, so
check the air intake for leaks or cracks just to be safe. The coolant is causing excess wear. Iron is from steel parts, probably rotating shafts since we've got lead from the bearings. The bearing area is traditionally
what coolant affects first. It's hard to say where the leak is. Have you done a pressure test yet? Keep changing oil more frequently until fixed."

 

[iamdub]

Also: Quick peeve. It's silicon, not silicone. He isn't running a ***** in his crankcase

LOL

I'm usually pretty sharp with catching my laptop's auto-completes (auto-INcorrects). But, you're correct and I understand the peeve!

 

[clandr1]

Blackstone told me that high levels of silicon is from an internal coolant leak mixing with the oil. Perhaps at some point someone put silicate coolant in the radiator and it's mixed in with whatever you have in there now. Either that or you go Baha racing and suckin in that sand??

I know I didn't share that part of the chart, but my water and antifreeze content are 0.00%, so I can safely rule that out.

 

[clandr1]

Quick update: I installed a new AC Delco air filter today. I noticed that one of the four screws that holds the air filter box closed had stripped out of the plastic housing, so I replaced it with a larger screw. That may have been the culprit that caused an unfiltered air leak. I'll report back when I change my oil and have it analyzed again.

 

[clandr1]

This may be a premature bump, but I changed my oil today after 8,192 miles. I pulled a sample and shipped it off to Blackstone today so I should have an update in the next couple of weeks. I'm hoping the new air filter and replacing a screw on the air filter housing in order to make it more secure will have fixed my high silicon content issue...

 

[clandr1]

I received my oil analysis today. My two concerns were lead and silicon.

Lead:

After replacing a faulty oil pan pickup tube o-ring in December 2017, my lead has dropped considerably from 22, to 14, to 13. It appears this is just normal for my motor given the history going back to June 2015 around 133,000 miles. So, it appears things are doing well on this front, even if my vehicle averages are about twice the universal average. I'd love to hear anyone chime in who has had oil analysis done on their rig to see if they are seeing the same, or something different.

Silicon:

As for silicon, it dropped from 22 to 16, so I'm going to call the new air filter and additional/larger screw in the housing a win. It is actually the lowest it's been in the last 3.5 years/60,000 miles, so that is encouraging (again, despite being higher than the universal averages column).

Other than that I'd say the old girl is doing well for approaching 200k!

 

[SnowDrifter]

Nice good deal!

If silicon is still a concern, switch oils and/or look at some VOAs. Some use it as an anti foam agent in small quantities