Oil Analysis Report

Thanks for posting the results. I have read that silicon in the early days can come from engine sealants, while later in life it indicates dirt getting past the air filter.

But just to play it safe, have you checked the air filter?

I have posted oil analyses previously and will look for those messages if you want to see the differences.

 

tochatihu could you re-post them, I remember a long time ago you posted them but can't seem to find them.
I'd look at the air filter and the sealing gasket around it as well. Also all connections from the air box and the resonator chamber under the air filter box to the throttle body. But also a lot of aluminum engines use high silicone content aluminum but my search on the 1NFZ engine doesn't mention this. But who's to know for sure with out consulting Toyota. If they'd tell you.

 

I agree with the silicone coming from the sealants. That was my thinking too.

 

[font=Comic Sans MS:b89233d646]Silica, silicon, silicone — let's try to keep these compounds distinct.[/font:b89233d646]

 

Thanks for the heads up, I never paid attention to the distinction.

 

I attach an excel spreadsheet of prius oil analyses. Not much metadata, but probably this is just to look at the averages. Mine were done at Blackstone, but not all of the others were.

On that Silicon terminology, I would also prefer to keep them all straight, but the different species are all reported the same by the analysts. The soil would be silica, the sealant silicone, the metal alloy additive silicon, and the form actually analyzed, probably atomic silicon stripped of several of its electrons. Assuming they are doing plasma spectroscopy.

 

partly my fault for the silicon/silicone with the alloy element. Sorry. For the years that GM made the Vega with the iron coated pistons and the hi-silicon alloy block they always had high readings on oil analysis tests

 

Tadashi, I found Blackstone to be very responsive to questions. I asked them details about the "total base neutralization" procedure. Suggest you ask them if Si values that high are common on first oil changes, and may be attributed to silicone sealer in the engine. In my Prius, the first oil I had analyzed was the sixth oil/filter change, so my high Si could have been long gone.

 

Tadashi, would you post those analyses again please? I neglected to copy them before and now they seem absent.

Here is my latest engine oil analysis, using Mobil 1 synthetic 0W20 for the first time.

First data column is Virgin oil analysis, data from the "BobIsTheOilGuy" VOA library. Second column is my UOA analysis at 77600 miles; this oil and filter had run for about 7500 mi. Units are parts per million (PPM), or as indicated. This used oil is still in service with a new (Toyota brand) filter, topped off to 'midway between the dimples'.

ALUMINUM 2 3
CHROMIUM 0 0
IRON 1 8
COPPER 0 0
LEAD 1 0
TIN 0 0
MOLYBDENUM 82 62
NICKEL 0 0
MANGANESE 0 0
SILVER 0 0
TITANIUM 0 0
POTASSIUM 1 1
BORON 226 104
SILICON 3 9
SODIUM 10 5
CALCIUM 3199 2658
MAGNESIUM 22 16
PHOSPHORUS 1020 718
ZINC 1144 846
BARIUM 0 0

TOTAL BASE NUMBER xxx 3.1

SUS VISCOSITY @ 210 ºF (53 to 59) 56.3
FLASHPOINT IN ºF >355 385
FUEL % 0 <0.5
ANTIFREEZE % 0 0
WATER % <0.1 0.0
INSOLUBLES % <0.6 0.3

I have emailed Blackstone asking if they know the "virgin" total base number for this oil. My guess is about 12, the value for the 5W30 grade. They commented that Prius engines are especially clean, not shedding metals from engine wear.

 

Thanks for reposting and sorry to have put you through the extra work, Tadashi.

If there were problems with the original sampling technique, it most likely would have showed up as water or fuel dilution. But those are fine.

We did not discuss your copper before, but that number also stands out among all the Prius UOA I have seen. We should expect (and hope) that this will decline rapidly with engine break-in. Simeon Baldwin's UOA at 15k miles was the youngest I had previously seen, and it did not contain copper.

If you post a subsequent oil analysis later, I promise not to ask for it twice!

 

what kind of washer are you using on the drain plug? copper? As I haven't seen a blowup of the VVTi set up there is a possibility of a copper alloy thrust washer or two in there that could contribute to that reading.

 

<div class='quotetop'>QUOTE(tochatihu @ Jul 29 2005, 01:19 PM) [snapback]111463[/snapback]</div>

Hi Tochatihu,

I hope that it is ok with you that I have modified the spreadsheet that you created. If not, let me know and I will desist or you can change it back to the way you would like it and I will stick with that format. The reasoning behind leaving out the Cu as a sort is that the high copper seems to be a break in issue that goes away at 5K to 10K on the engine, and the reason for sorting on oci, iron, and aluminum is that I wanted to see what happened to the wear metals as oci increases, so far you seem to have the longest oci I have come across on a Prius I with Scott Chase having the longest on the Prius II. You mentioned in this post that the 0W20 was still in service, but there is no second UOA on Mobil 1 0W20, did you do a second analysis with more miles on the 0W20? Also it looks like you did an analysis on Mobil 1 5W30 at 7K and then kept the oil in service another 6K and did a second UOA is that correct. The wear numbers on the second 6K were about as good as I have seen anywhere! You could have changed the filter and gone for another 5K! I assume you changed the filter at 7K and then carried on another 6K, is that correct? If you could give me the dates of your analyses I would appreciate it. Thanks.

Dennis

 

My search for engine oil analysis did not reveal the thread where Maineprius put the most recent UOA spreadsheet.

I just got a UOA for Mobil 1 5W30 in 2001 Prius, 12k/104.5k miles, and will highlight some numbers here.

The wear metals, Al Cr Fe Cu Pb Sn, are just as found in my previous 11k/92.5k UOA. In other words, ignorably low and with no trend, or zero.

The silicon is 17 (previous 14) and while Blackstone did not highlight that, the overall small upward trend is unwelcome. Sooner or later I may stop using the K&N oiled engine air filter and go back to short-cycle paper filters. Si should not be a really issue until the wear metals also increase, but I would like to stay ahead of any such problem.

The fuel dilution was 1%, and this has been a recent topic of discussion. In this case I did a thorough engine warmup, followed by leaving the filler cap off during a 20 minute or so cooldown before sample&drain. The idea was to give the fuel an opportunity to go away. I suspect that Prius crankcase ventilation is not always adequate to get that stuff back into the 'burn path', especially with older PCV valves (mine is still original).

However, also important to note that the problem with fuel dilution would first present itself by the oil viscosity going below its specified range. That has not occured in this UOA or any of my previous.

It would probably make sense to change the PCV valve early in this next oil cycle and see (later) if my fuel dilution decreases.

 

I just added a few of my analyses and put a reply in to bump the thread. A search on "oil analysis" in the title should usually find the thread if it falls to the bottom. Feel free to post it here and I will add it, or you can do it if you like.

Dennis