2008 BMW M3, BMW TwinPower Turbo 10W-60, 4915 mi

[d00df00d]

Previous UOA here. Now at 105176 miles on the engine.

In the 20k miles prior to this OCI, I caught and fixed at least 3 possible causes of fuel dilution: failed coolant thermostat, a precat exhaust leak, and a precat O2 sensor failure. Each time I hoped the fuel dilution would come down. Maybe it finally happened, if only slightly.

Nothing else of note in this OCI.

Copying the numbers here because I don't like how Polaris's reports are formatted:


Wear Metals
Iron - 6
Chromium - 0
Nickel - 0
Aluminum - 3
Copper - 2
Lead - 0
Tin - 0
Cadmium - 0
Silver - 0
Vanadium - 0

Particle Quantifier (PQ) Index - 13


Contaminant Metals
Silicon - 7
Sodium - 10
Potassium - 0


Multi-Source Metals
Titanium - 0
Molybdenum - 44
Antimony - 0
Manganese - 0
Lithium - 0
Boron - 49


Additive Metals
Magnesium - 21
Calcium - 2249
Barium - 0
Phosphorus - 716
Zinc - 828


Other Contaminants
Fuel Dilution - 1.5% (GC)
Soot - Water -

Fluid Properties
Viscosity @ 100º C - 17.6 cSt
TBN - 4.31
Oxidation - 11
Nitration - 10

 

[dparm]

Looks good. I wouldn't sweat it with the fuel dilution if you're driving the car the way it was meant to be.

Curious why you added 2L between changes versus 1L on the previous ones. The digital dipstick was always a bit awkward on that car...

BTW, has it had bearings changed out?

 

[d00df00d]

Originally Posted by dparm
Curious why you added 2L between changes versus 1L on the previous ones. The digital dipstick was always a bit awkward on that car...

Polaris only lets you enter integers for amount added. The real amount was more like 1.5L, and that was at least partly because I hadn't achieved a full fill from the get-go.

I know I'm losing some oil through a weep at the oil fill cap that I never bothered to completely fix. I did a quick thing to reduce it a while back; maybe it has gotten slightly worse since then.

Originally Posted by dparm
BTW, has it had bearings changed out?

(Rod bearings, right?)

Yes. Had that done around 82k miles. BMW bearings and bolts, so it now has the newer lead-free bearings.

 

[dparm]

There was a revised oil cap IIRC, but they all sorta weep. Hope you're still hooning it on a daily basis!

 

[d00df00d]

Originally Posted by dparm
Hope you're still hooning it on a daily basis!

 

[BMWTurboDzl]

Low tension rings my friend. Fuel dilution is always going to be there.