This is the second oil change since a fuel filled crankcase and a injector change. ~4500 miles on this oil.


IRON - 12
MOLYBDENUM - 39
ZINC - 1536
PHOSPHORUS - 1391
CALCIUM - 1977 (DOWN FROM 2332)?
MAGNESIUM - 417

POTASSIUM - 33 (DOWN FROM 167)? Possible coolant leak or just leftover from the crappy job the stealer did when injector tube installed improperly?

SODIUM - 12 (DOWN FROM 27)
BORON - 35
SILICONE - 15 (DOWN FROM 32)
SILVER - 0
NICKEL - 0
ALUMINUM - 0 (DOWN FROM 3)
TIN - 0

COPPER - 37 (DOWN FROM 139) I know the is very bad! but much better... I hope this is a trend..

LEAD - 6 (DOWN FROM 28)
CHROMIUM - 0
IRON - 12
FUEL - A
WATER % vol <0.1
GLYCOL - N

SOOT - <0.1
OXIDATION - 11.00
NITRATION - 6.00

MOTOR HAS 155000 miles on it now, injectors changed at 148,000, runs great - plenty of power

All your wear metal #s are low except copper, which is trending down, so I think it looks pretty good. Chromium, tin, & aluminum are 0 which is great. Hopefully the potassium & sodium keep dropping. Things like calcium, phosphorus, & zinc are just oil additives that change with different brands of oil. What oil did you use in each analysis?

Dealer changed the oil, the service writer could not tell me what kind... :mad:
I am now running Rotella T synthetic, I agree about the trend, I hoped someone would see it that way as well.

Several have posted since this forum started that the Duramax runs a little higher copper numbers than other engines. Since the metals that make up babbitt (lead, tin etc.) are good it looks like you might have dodged a bullet. One of these days I might get to see a Duramax completely disassembled. I will find what is giving up the copper. Possible the crank thrust bearing or brass pump bushings et. Later! Frank

My analysis was low on everything except Copper. I am using Amsoil. The lab indicated it could be an oil attitive or bearings wearing. I called Amsoil to find out if they had copper in their oil.

Their Analysis specialist indicated that on a Duramax, it copper comes fron Oxidation from the internal oil cooler. He indicated that this is not a problem.