Contaminated oil - vs - contaminated sample

[Scooter]

I just posted my results of an interesting and disturbing oil analysis in the Used Oil Analysis Section. My silicon number is quite high yet my wear numbers look really good. I have to consider that either myself or the oil analysis lab may have contaminated the sample. I sample with the Amsoil sampling pump through the dipstick and use new tubing for each sample. So, can you oil analysis pros spot a contaminated sample versus just plain old dirty oil? I will be draining the oil and taking my 10k sample in the next few days. That sample should confirm whether the silicon count is for real or simply an error.

 

[MolaKule]

If the silicon comes from RTV and similar sealants made of silicones, a form of silicon, you won't have high wear numbers from the gritty type of silicon called "sand" and dirt.

 

[Spector]

At 28,000 miles it should be finished breaking in. All the other numbers are very consistent so the high silicon is strange. Personally, I would not worry about this as the wear numbers are great. Could be a bad result, some outside contamination etc but if this high a silicon is dirt you would see considerably higher iron numbers as well as others. You can call the lab and ask to recheck but I would not jump off of a cliff due to this one number. You have great trend analysis here and one strange number does not a problem make.

I also have used the Amsoil tube etc. but unlike you I uese the same one everytime and just blow it out. I don't think that whatever is left in the tube can cause much of a problem, at least it has not for me.

 

[Scooter]

UPDATE: I just posted my 10k mile results in the UOA section. Silicon dropped from 54 to 19 which confims my suspicion that my 7.5k mile sample was contaminated.