Higher than expected Ti and Si in Oil Analysis

JLuetjen2

New member
Joined
Mar 11, 2017
Location
MA
TDI
2012 Passat
I just had a Blackstone Oil analysis done and everything looked good except that the Titanium came in at 22 versus a universal average of 2, and the Silicon came in at 24 versus a universal average of 4. I'm trying to think of what components in the engine would have those two materials in them -- I'm thinking the turbo compressor(?). The verbiage on the report didn't mention anything about these two readings.
The car has about 122K miles on it.
Any thoughts from others who may know more about this TDI engine than me?
- John
 

740GLE

Top Post Dawg
Joined
Aug 19, 2009
Location
NH
TDI
2015 Passat SEL, 2017 Alltrack SE; BB 2010 Sedan Man; 2012 Passat,
Si is usually from sand, did you change the engine filter recently?
 

JLuetjen2

New member
Joined
Mar 11, 2017
Location
MA
TDI
2012 Passat
I suctioned the sample from dip-stick tube. The filter was changed a few months ago by a dealer. The car just gets normal over-the-road usage. Rarely does it see a dirt road.

Looking at the materials used for turbochargers (based on the high Ti content also measured), I see that Si is used in high temperature cast stainless steel turbo housing in proportions of about 0.5% to 1.5%. But since there aren't other materials (Fe, etc) aside from the Ti which are elevated, I doubt that it's from there. I'm not sure if TDIs of this family use any sort of silicon surface on the cylinders like Nikasil or Alusil. Looking at the alloys used for Turbo wheels (alpha, beta, alpha-beta alloys) I don't see any Si listed in the composition.

The mystery continues.

Thanks for the quick response though.
 
Top