I want to know what can be the sources of silicon contamination apart dirty in marine motors.
Kisses

Sand

Silicon on its own can be from a silicon grease or assembly compund or anti foaming additive. Also it can be one of the elements that show up when there is a coolant leak.

I trying to determinate the failure at the motor through Si content and others metals contents.
I observe when there is a several dirty there is a relatin between Si-Al.
-What is the provenience of sand?
-When there is a coolant leak, I observe that there is an increment of sodium content with the Si,but it depends of the coolant or no? Is the Na reemplace by Calcium today? I observe also that the Cu content increase, but now the tubes of conduction are change by another material?
Thanks

@esti
Liquid gasket sealings are a source of Silicone, too. The Al which you observe together with dirt seem to clearly come from the bearings.
Sand is used as die cast material during cylinder block /cylinder head production.
It is rather hard to clean a new block completely from sand which is situated in oil channels, etc.

You are right with your coolant observations. Silicone in coolants is a classic chemistry for coolants. New longlife coolants are most of the time silicone free and have Kalium instead of Natrium.

The copper may come from welded oil cooler fittings, sometimes bearings, etc.