Silicon Common Entry Points Into Oil

[Fallguy]

What paths can silicon contamination enter.

(1.) Air filtration equipment and connections, then into combustion chamber, then past rings, valves etc.

If you believed your air filtration and connections to be ok what other paths would there be.

Contaminated fuel washing past rings, pcv

New car, silicon was high(56), 5k mi run on oil from 4-9,000 miles. Have changed oem air filter (now napa gold wix air filter on), see what next UOA shows. Maybe my dirty hand brushed the top of container during sample not sure

 

[river_rat]

New car. Silicon sealants leaching into the oil, probably.
56 ppm seems pretty high for actual filter infiltration unless you live on a sand dune.

 

[unDummy]

Sand dune is what happens if you live in a snow state that uses excessive road sand and salt(along with other car eating chemicals). Si/K/Ca/Na, along with God knows what, can be in that winter sand/chemical paving solution.

My air filters get changed almost every year because of the sanding trucks. Its not worth taking apart the airbox to remove a cup of sand and not replace the filter at the same time.

Fuel! Besides unfiltered air and RTV sealant, dirty fuel can cause higher Si readings. This means that maybe your gas station isn't changing the pump filters on time, or they're not clogging because the media is damaged. So, you might get Si and even Pb from your fuel. If a tanker empties an Avgas load and then refills the next day with gasoline for your station, hello lead!

Unfiltered air....don't forget, when you run your gas tank empty, it fills up with air. Where does that air come from and what is in it? Trace your tank vent lines. Or, the previous customer dropped the nozzle and got it dirty...you're next in line

 

[stubbakatt]

Originally Posted By: river_rat
New car. Silicon sealants leaching into the oil, probably.
56 ppm seems pretty high for actual filter infiltration unless you live on a sand dune.


Or maybe if you lived here:
http://www.bobistheoilguy.com/forums/ubbthreads.php?ubb=showflat&Number=2211825

 

[river_rat]

Originally Posted By: unDummy
Sand dune is what happens if you live in a snow state that uses excessive road sand and salt(along with other car eating chemicals).

Good points, but AFAIK, we no longer use sand in Iowa. Salt only, and even if it looks like flurries. The sand wasn't corrosive enough to get the full kickbacks from the automakers.

 

[SteveSRT8]

In a new car unless something was defective or mis-assembled at the factory virtually no sand can enter the engine from anywhere.

Fuel is filtered, air is filtered, evap system is filtered, etc.

I'm betting on sealants as a spike in the UOA and it will decline with time.

 

[ltslimjim]

It's still possible the filters in place aren't getting the fine particles and allowing some into the engine. Possibly?

 

[cchase]

Originally Posted By: river_rat
Originally Posted By: unDummy
Sand dune is what happens if you live in a snow state that uses excessive road sand and salt(along with other car eating chemicals).

The sand wasn't corrosive enough to get the full kickbacks from the automakers.


LOL!

 

[Samilcar]

New car means new gaskets and sealers, which means high SI on UOA's. Our new van showed almost 300ppm SI when the factory fill oil was sampled at 800 miles. The SI took 20,000 miles to finally trend down to normal (under 10ppm).

 

[98Auburn]

Fallguy, what were your Fe, Cu and Cr readings? If they are normal then it's the sealer, but if Chrome is up with Iron then it's an intake air leak of some type. 56 is to high for contamination by you. You would have known you contaminated the sample. My personal thought is the sealer.

 

[rksk]

I have not studied the current engine manufacturing technologies, but are they still using sand casting for engine blocks, heads and manifolds? Could residual sand from the casting process be a source of silicon in a new engine?

 

[SteveSRT8]

It has been known to happen but it is very rare.

A new engine full of sand is extremely unlikely as it would yield failures.

 

[SIXSPEED]

Sometimes silicon is in the virgin oil. I've seen VOAs of Red Line oil reporting Si levels from 12 to 64 ppm. Hate to be chasing a potential air leak when the silicon was there in the first place. That's why I like to baseline a virgin oil sample just to see what it's got in it.

 

[spackard]

Strangely enough I think I get it by driving in the Pasadena, CA area during early morning hours when a lot of leaf-blowers are cleaning dust off the sidewalks and blowing it into the traffic lanes.
The dust is very fine. Every blower-guy doesn't pick it up; they blow it in the street, the cars create a wind that blows it into other traffic and to the shoulder, and the street sweeper vehicle eventually sweeps the gutter up. Cycle repeats every week.