Silicon from sealant - released with time or use?

[medic]

We've all seen the used oil analysis with high silicon & low iron in newer engines - this is supposedly blamed on sealants used when manufacturing the engines. TooSlick has said that certain engines (Fords and others) will show high silicon until at least 50k miles. I accepted this until I saw a used oil analysis on a Ford 4.2L that only had 7,200 miles on the engine with 3,100 on the oil. The silicon was at 9 ppm. THe thing is that this engine ran the 3,100 miles in less than a month. This got me thinking that the silicon is released over time and mileage has nothing to do with it.

If this theory is correct, then a 12 month old vehicle with 90k miles could still show high silicon from sealants if the OCI was decreased to 3,000 miles over 3-5 months.

Any thoughts?

 

[Ray H]

I'd presume use, but perhaps really related to heat of operation, though.

 

[Al]

Just relying on my memory (which isn't always very good)-I'd say it is a combination of both. The silicon comes from many parts of the engine-probably. Its just a function on what period of time and how much the oil contacts the parts with silicon. Also the silicon could be a sealant (RTV) or part of a gasket. I just think there are a lot of variables. Just seems in general that the silicon in most just dies away at different rates and it also depends on how high it initially is.

I realize I'm just rambling