Used Oil Analysis

[PhilNZ]

Hi folks
Completed my first oil change as part of IMS Guardian install (some pics on my Rennlist thread). Was due in July for 12 month service so its been 10 months or 6000 kms since last change. Engine run exclusively on Mobil 1 from new and has done 109,000kms. Current grade is 5w 50. UOA is:
Cu 23ppm
Zn 817
P 709
Fe 8
Al 2
Cr 1
PQ 0

Main concern is Cu but Zn and P are lower than nominal (1100/1000). Have refilled with Fuchs Titan Supersyn 5w 40 and will check again in 6 months. Interested in your thoughts/ comparisons.

[Flavor 987S]

At my fall oil change, with Mobil 5W50 my copper was at 7 and my Zinc and Phos. were at 1,669 and 1,196 respectively. Our Alum and iron number are similar. About 52,000 miles on the motor and 6,700 miles on that oil.

[san rensho]

Copper is high, but not stratospheric. I would just do another short interval oil change and check the copper.

Phosphorus and zinc are low, but those are anti wear additives which vary from oil brand to,oil brand.

[PhilNZ]

Originally Posted by Flavor 987S

At my fall oil change, with Mobil 5W50 my copper was at 7 and my Zinc and Phos. were at 1,669 and 1,196 respectively. Our Alum and iron number are similar. About 52,000 miles on the motor and 6,700 miles on that oil.

Thanks, good data. Looks like I'm being short changed on Zn. Your Zn level is double mine and were using the same brand/grade of oil. Mobil 1 gets the big thumbs down from me. I dont think that variability is acceptable at $20/L. Pleased I changed brand but need more data to know if its the right choice.

[paulv]

Phil,

Do you know the particle size range that the lab's equipment can see? Many spectrometers can only see up to about 5 to 10 microns, and usually report in the up to 1-2 micron range. Hardened steel will flake off and cause ~15 micron (and larger) sized particles -- these would never be detected and reported (depending on the equipment).

Regards,
paul...

[PhilNZ]

Originally Posted by paulv

Phil,

Do you know the particle size range that the lab's equipment can see? Many spectrometers can only see up to about 5 to 10 microns, and usually report in the up to 1-2 micron range. Hardened steel will flake off and cause ~15 micron (and larger) sized particles -- these would never be detected and reported (depending on the equipment).

Regards,
paul...

Thanks, interesting comment. I'll give the lab a call and find out. The filter was clean and there was no particles visible in the sump or the oil pan so I'm hoping shes clean