I made a switch from using Mobil 1 Synthetic 5w/40 to using Shell Rotella T6 Synthetic 5w/40. Since making the switch, my oil analysis have been coming back with high silicon readings. I change oil at a 10,000 mile interval and have never had a problem with the Mobil 1 analysis. I've checked over my intake and changed my air filter as suggested and everything appears to be clean and tight. Is it possible that the silicon is coming from somewhere else? Are these readings acceptable, or should I switch back to the Mobil 1? I've attached the three oil analysis that have been done since switching. Thanks for your help!

what do the Mobil 1 sheets look like??

the MOLYBDENUM is a coating used on pistons, but could also be a product within the oil make up.....I'm thinking the same for the silicon; that it is a product within the oil make up

I only have hard copies of the Mobil 1 report, no .pdf's. I'll try to get some of the info and copy it over. However, I do know that there was no mention of high silicon readings and that everything looked good.

Are you driving it in a dusty environment?

Take your resonator off and check it for cracks. A couple of years ago, a member on here got a "high silica" report and found the resonator was cracked and letting in unfiltered air.

Since then, a lot of us have removed the resonator and installed an ABS plug in the turbo mouthpiece to eliminate the problem.

Well I just put in T6 and will get it tested and post what the results are when it gets changed.

Little bit concerned.

The silicon is the thing to adress; all else is fine.

You have an air-intake leak somewhere. The Si has been climbing for the last few successive UOAs. That is not oil related; it's a leak. At the rate it's going, it will be alarming soon. You may have to take your entire system apart, piece by piece, and look for cracks or un-seated seals. Have a friend come over and help; often a second pair of eyes sees things you ignore or take for granted.

When I got home from work tonight, I took the whole intake apart from the filter housing up to the turbo. Everything looked clean inside. I looked over the resonator, the plastic elbow and flexed all the rubber sections and couldn't find any cracks or damage. I looked at all the junctions and couldn't see any obvious place where dirt was getting through. Put it all back together and made sure all the clamps were tight. Not sure what else to do? Does it sound like I'm checking everything that needs checked, or am I overlooking a part of the intake system? I'll have a second set of eyes take a look at it when I can, but that might be a little while. Provided I can't find anything, how many miles should I run before having another analysis done? This has me a slight bit concerned...would like to get it taken care of. Looked back over my report with the Mobil 1 and silicon was at 9 ppm. Thanks gain for your help.