11 M3 / Castrol SAF-XJ 75w140 / 36,200 miles

[dparm]

Code:
OIL Castrol SAF-XJ 75w140 + FM

MILES IN USE 36,200

MILES 64,500

SAMPLE TAKEN 3/29/16



ALUMINUM 1

CHROMIUM 3

IRON 352

COPPER 1

LEAD 0

TIN 1

MOLYBDENUM 67

NICKEL 1

MANGANESE 9

SILVER 2

TITANIUM 0

POTASSIUM 2

BORON 160

SILICON 288

SODIUM 2

CALCIUM 5

MAGNESIUM 0

PHOSPHORUS 2562

ZINC 15

BARIUM 1



SUS Visc @ 210F 117.2

cSt Visc @ 100C 24.32

FLASHPOINT ºF 390

Fuel % N/A

Antifreeze % N/A

Water % 0

Insolubles % 0.2

TBN untested

TAN untested




Gear oil was in there for about 46 months and saw a bunch of autocross events, two track days, and plenty of WOT. The car is stored over the winters. It's also not really a DD since I typically fly during the week. The differential is a GKN Visco-Lok unit with integrated speed-sensitive LSD.

I have never had the rear differential fluid analyzed since it's the first change I did while owning the car. BMW specifies changing it every third oil change, but Blackstone says things look on-par other than slightly high iron. They did call out the elevated silicon but said it's likely an anti-foaming agent or something like that. The high phosphorous is likely the additional FM.

Also worth noting that this is Castrol SAF-XJ but has extra friction modifier (FM) per BMW's specification. Apparently there were complaints about chatter in the first year the car was out, so the fluid was revised with extra FM. I opted to stick with the standard FM dose when I had it changed, so it now has Castrol Syntrax LS 75w140, the new name for SAF-XJ. I think every third oil change is fine for me given my relatively low annual mileage.

 

[zeng]

It appears to me the oil is still good with its additive elements and KV@100*C ....
Does the used sample indicates goldenish hue?

But the iron and silicone appears high to me , how would one explain this ?

 

[dparm]

Not that I remember, Zeng. It looked like any other used oil.

Blackstone wasn't sure about the silicon but said that it's probably not contamination since this is a closed system (unlike a crankcase). Their guess was an anti-foaming agent.

 

[MolaKule]

The silicon level is very high and no new oil would ever have over 10 ppm.

Have you recently or in the past replaced the rear diffi cover and sealed it with RTV? Has the diff gone through a lot of mud and or water?

I would try a run of Amsoil Severe Gear and run it for the same period to see how things shake out.

 

[dparm]

Originally Posted By: MolaKule
The silicon level is very high and no new oil would ever have over 10 ppm.

Have you recently or in the past replaced the rear diffi cover and sealed it with RTV? Has the diff gone through a lot of mud and or water?

I would try a run of Amsoil Severe Gear and run it for the same period to see how things shake out.






Nope. I wonder if the dealer just didn't do a good job getting a sample during the change.

There's no records that the car has ever had any work done on the diff other than the fluid changes.

 

[zeng]

Originally Posted By: dparm
Not that I remember, Zeng. It looked like any other used oil.
Blackstone wasn't sure about the silicon but said that it's probably not contamination since this is a closed system (unlike a crankcase). Their guess was an anti-foaming agent.


If the high silicon is purely from anti-foaming agent within oils, then that's bad news as the high iron ppm is 'real' red flag.
Whereas if the high silicon is attributable to contamination .. then it could be contained or eliminated.

After a typical 'harsh' run , any intention on your part to periodically measure diff casing temperatures with an IR gun or palm touch ?

 

[MolaKule]

There is no way Castrol would put that much anti-foaming agent in a GL.

It has to be either 1) contamination or 2) the heat treating was insufficient.

 

[dparm]

Originally Posted By: MolaKule
There is no way Castrol would put that much anti-foaming agent in a GL.

It has to be either 1) contamination or 2) the heat treating was insufficient.



I guess my question is, "what's the course of action"?

The car has 65k on it and about a year of warranty left, but it still drives flawlessly and has been trouble-free. The diff doesn't make weird noises or anything.

Can we just chalk this up as sloppy sampling by the dealer?

 

[zeng]

Originally Posted By: dparm
I guess my question is, "what's the course of action"?
The car has 65k on it and about a year of warranty left, but it still drives flawlessly and has been trouble-free. The diff doesn't make weird noises or anything.
Can we just chalk this up as sloppy sampling by the dealer?


Just pray it's sampling issue ..... but it might be wishful thinking.
I would play it safe by assuming it's not sampling issue....
and if you had dumped in another 75W140 at this oil change ,then do another UOA at shorter interval of, say 25K miles, wait for results to evaluate whether you can keep it longer than 25K or replace oil with a thicker 80W140 etc.

The weird whining noise, if it ever come , would not be so soon .....but possibly 100K to 150K down the road, by which time it's too late.
JMHO.

 

[DWC28]

Originally Posted By: dparm

I guess my question is, "what's the course of action"?


Sorry for the late arrival, hope the gears have not exploded. In determining a course of action from oil analysis one item is to see if the results are accurate and if they indicate any harm. The silicon level is very high, the cause for this is not determined, poor sample, anti-foam, gasket sealer, dirt or implants. Needs to be determined. Often you can feel the oil for grit. If damage is being done you should see it in the wear metals. Iron appears high to me, but there is no history to compare. With possible contamination and possible wear; change the oil, flush the system, resample. Don't drive far from home.

 

[MolaKule]

Quote:
...but Blackstone says things look on-par other than slightly high iron. They did call out the elevated silicon but said it's likely an anti-foaming agent or something like that. The high phosphorous is likely the additional FM...


The iron indications are high for that mileage.

However, the silicon is indicative of RTV or an ingress of dust and dirt. High silicon in the form of abrasive dust can increase wear. Breather hose maybe?

Anti-Foam (Af) levels should be on the order of 5-20 ppm, so it's not the AF.

The high phosphorus is part of the Extreme Pressure (EP) additive component.