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2020 Subaru Outback 2.4l Turbo, Mobil 1 T-SUV 5w-30/AFE 0w-20 Blend, 3300 mile OCI, Copper Increase, OAI vs. Blackstone
- Thread starter Jack_Kieran
- Start date
Comments on my UOAs posted above:
UOA by OAI shows INCREASE in Copper level. What level concern should I have? Suggested course of action?
Lab error can be ruled out, as I had retained more of drain sample and sent it to Blackstone for comparison, and they got similar Copper result.
OAI also showed slight increase in Lead and Sodium values, but they did not flag as abnormal. Blackstone did not show any Lead, and a much smaller Sodium value.
Previous interval showed normal value of Copper after steady decreases in successive checks, as expected, as this vehicle with still fairly-low 18,000 miles went thru break-in.
Oil used in latest interval (OAI #5 sample) was same blend of Mobil 1 type/ viscosities (albeit from different jugs) as in OAI #4 sample: 63% Truck & SUV 5w-30 plus 37% AFE 0w-20. Interval 4 used Napa Gold 7055 filter, interval 5 used Fram Ultra XG7317.
Interval 5 had 50% more miles (3300 vs. 2200), 8 month time interval vs. 2 months, and a greater proportion of shorter trips.
I did start using Union 76 gas in latest interval in addition to the previous typical Costco, Chevron, Shell. Always 92 octane premium.
On a positive note, this oil blend held its viscosity very well in both intervals, dropping from a calculated kV100 of 9.3 when new to 8.5 after use. This despite the fuel dilution of 2.5% which is typical for this GDI turbo engine.
UOA by OAI shows INCREASE in Copper level. What level concern should I have? Suggested course of action?
Lab error can be ruled out, as I had retained more of drain sample and sent it to Blackstone for comparison, and they got similar Copper result.
OAI also showed slight increase in Lead and Sodium values, but they did not flag as abnormal. Blackstone did not show any Lead, and a much smaller Sodium value.
Previous interval showed normal value of Copper after steady decreases in successive checks, as expected, as this vehicle with still fairly-low 18,000 miles went thru break-in.
Oil used in latest interval (OAI #5 sample) was same blend of Mobil 1 type/ viscosities (albeit from different jugs) as in OAI #4 sample: 63% Truck & SUV 5w-30 plus 37% AFE 0w-20. Interval 4 used Napa Gold 7055 filter, interval 5 used Fram Ultra XG7317.
Interval 5 had 50% more miles (3300 vs. 2200), 8 month time interval vs. 2 months, and a greater proportion of shorter trips.
I did start using Union 76 gas in latest interval in addition to the previous typical Costco, Chevron, Shell. Always 92 octane premium.
On a positive note, this oil blend held its viscosity very well in both intervals, dropping from a calculated kV100 of 9.3 when new to 8.5 after use. This despite the fuel dilution of 2.5% which is typical for this GDI turbo engine.
On the one hand, this vehicle has less than 19k miles on it, so it could easily be break-in still washing out. On the other hand, there have been 5 oil changes, so you'd think it all would've washed out by now. I've seen results where the break-in doesn't end til >25k miles, so I'd suggest wait til at least then before you draw any conclusions.
Thanks for another data point on gas chromatography vs fuel estimation. <0.5% vs 2.5%.
Thanks for another data point on gas chromatography vs fuel estimation. <0.5% vs 2.5%.
All of the Subaru 2.4Ts have oil coolers, so copper in these is generally NOT from bearings. At less than 20k miles, this is likely still normalizing even though it went up some here.
From what I have seen in the FA20DIT (old uoa's on nasioc), there was not much difference in the rate that break-in wear washed out in 3k mile or 5/6k mile OCI's.
The Si in my XT was 28 at 24,257 miles and 21 at 28,743 miles using paper filters and ~4,500 OCI's. Cu was 14 and 7. Si seems to take a while to wash out and hopefully your Cu will drop. Odd that it shot up but maybe it's just noise/oil cooler/slow break-in/etc.
The Si in my XT was 28 at 24,257 miles and 21 at 28,743 miles using paper filters and ~4,500 OCI's. Cu was 14 and 7. Si seems to take a while to wash out and hopefully your Cu will drop. Odd that it shot up but maybe it's just noise/oil cooler/slow break-in/etc.
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Copper leaches from the oil cooler, probably through a corrosion process. To a certain extent it probably happens even when the engine isn't running, but faster in warmer weather, and much faster when the engine is running. Assuming copper corrosion increases with time, temperature, and mileage, these results seem pretty reasonable.
1.5 months: 15 ppm Cu
6 months, over winter: 35 ppm
7 months, summer to winter, with 50% more miles on OCI: 57 ppm
If you had 20+ ppm copper from bearings, I think you'd see more of other metals like lead, tin, and aluminum. Lead is a touch high at 3 ppm on the OAI test, but 0 ppm with Blackstone. I wouldn't worry about it.
1.5 months: 15 ppm Cu
6 months, over winter: 35 ppm
7 months, summer to winter, with 50% more miles on OCI: 57 ppm
If you had 20+ ppm copper from bearings, I think you'd see more of other metals like lead, tin, and aluminum. Lead is a touch high at 3 ppm on the OAI test, but 0 ppm with Blackstone. I wouldn't worry about it.
Good observation about the time-related component for copper pickup in oil, I hadn't considered that. It does seem to fit my most recent results. Also explains BlueSubie's general observation that shorter vs. longer OCIs don't seem to affect how long in total miles it takes for break-in related Cu washout to fully complete. Results of next UOA will be interesting.
Your point is validated by my latest UOA!
I had a concern about the Copper value in my OAI-performed sample #5. Now, my latest UOA (sample #6) shows Copper at a more typical value. It appears that there may indeed be a time-dependent component to Copper pickup. To wit: Sample #6 with OCI of 80 days shows almost exactly by 80/49 ratio the Copper level as sample #4 with 49 day OCI, with each OCI having about 2200 miles. Sample #5 OCI had about 150% the miles and 300% the time in days than sample #6, and about 250% the copper level.
Other key observation is my blends of Mobil 1 AFE 0w-20 with Mobil 1 T/SUV 5w-30 continue to show very low decrease in viscosity even with the fuel dilution typically seen in the GDI FA24F engine. For sample #6 blend, calculated starting kV100 viscosity was 8.9 based on published Mobil 1 specs, and over the 2200 mile OCI, that decreased only to 8.4 measured units.
What kind of oil cooler is that?
It's a regular piece of equipment on the car, not an aftermarket add-on.
A better name for it would be "oil heat exchanger" or "oil attemperator" because it exchanges heat between the engine oil and the coolant. When the engine is starting up and the oil is below the coolant temperature, it actually warms the oil. At regular operating temps, heat is dumped from the oil to the coolant. It's largely copper on the heat exchange surfaces, which is why the oil tends to pick up copper.
2019-2022 Subaru Oil Cooler 21311AA200 | OEM Parts Online
2019-2022 Subaru Oil Cooler 21311AA200
subaru.oempartsonline.com
I am very well aware of that.It's a regular piece of equipment on the car, not an aftermarket add-on.
A better name for it would be "oil heat exchanger" or "oil attemperator" because it exchanges heat between the engine oil and the coolant. When the engine is starting up and the oil is below the coolant temperature, it actually warms the oil. At regular operating temps, heat is dumped from the oil to the coolant. It's largely copper on the heat exchange surfaces, which is why the oil tends to pick up copper.
2019-2022 Subaru Oil Cooler 21311AA200 | OEM Parts Online
2019-2022 Subaru Oil Cooler 21311AA200
But why is leaving copper when it does not do that in other cars with similar heat exchanger? I have it on both VW's and to does not have any issues around copper. Is there something unique about Subaru ones?
If the copper spike isn’t due to the particular driving conditions, I think it could be due to the break-in wear metals not yet normalizing. It wouldn’t be the first time that there has been an odd spike in a Subaru uoa during the first 18k miles regardless of how many oil changes there have been.
My thinking is the same, though they should be trending down consistently and be in single digit numbers, unless there is something specific about this engine.
BrendanC
$100 site donor 2024
yes. the other manufacturers use plain aluminum.
That is why I asked is there something specific, as regular wear should not look like that.
BrendanC
$100 site donor 2024
as i alluded in my previous post, “other manufacturers use plain aluminum” so that must mean subaru uses copper
do a little research on the oil cooler. i almost bought one to retrofit on the K24 but chose to go with a hyundai unit due to the copper issues tainting UOA’s.
I am just saying why I asked the question.as i alluded in my previous post, “other manufacturers use plain aluminum” so that must mean subaru uses copper
JFC.
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