Oil Analysis

[BozDMAX]

At about 120K I started noticing smoke in the exhaust and some of the other signs of injectors needing replacement. I took a quick oil sample and sent it off for an analysis. I dropped the truck off at the dealer a couple days later and they started replacing injectors and I had them check and replace the glowplugs at the same time.

I kept pestering the company doing the analysis (I sent the sample priority mail) but they were slow in getting the sample posted to the internet and even though the turnaround on the truck was 8 days (!) the oil sample results did not get back to me for over three weeks. They didn't seem to be able to tell me over the phone, but kept assuring me it would be posted "tomorrow". The truck was still apart when they actually performed the analysis, and a quick report would have allowed the dealer to take a better look while things were apart for injectors. At that point, pulling the heads would have probably added only a couple hours of labor.

Truck got buttoned back up, runs like a dream, mpg up about 1-2 on the first tank and the analysis FINALLY gets posted and shows no fuel in oil but Potassium at 42 (previous readings were 0/3/5/2 on successive samples) with an evaluator comment to check for source of coolant leak.

While the coolant looks a bit low in the overflow tank, I have to admit that I hadn't added a drop or changed it in the four years I have had the truck and it was not something I looked at very often to begin with.

When the injectors were done, I provided the new oil and filters for the changeout. Tech added 12 quarts (I had provided 12, but told him to only add 11 on the changeout (it was in two and a half, 5-qt containers) so I drained the excess. I did notice in the drain container a few very-small (pin head size) bubbles in the oil. Today the DIC low-coolant warning came up on a start and I pulled about a 5-oz sample from the drain pan and put it in a glass jar so I could let it sit and see if there was any sign of separation in the AM.

It is not really apparent to me if I am making any oil. As I say, the truck is running great, so it is not like I suspect a cracked head or blown head gasket. I had thought I would get 1000 miles on the new injectors and send in another sample to see if it would still show a high potassium reading. Wondering now if I should even wait that long or just get it into the dealer.

Worst part is, we plan to head south for the winter in a couple weeks or so, and I am starting to wonder if I should be towing a 14K lb RV down to the DC area or delay the trip a bit while getting things fixed.

I am glad I am sampling, otherwise I probably would have not known for a long time about what may be a coolant leak.

Advice?

[Mark Rinker]

Whats to say that the oil sample is an insignificant trace and your low coolant indicator is simply consumption elsewhere?

I just replaced a waterpump on my 2001 at 150K. It only leaked occasionally, and then only briefly after a hard pull.

Me? I'd carefully examine the waterpump for any signs of leakage. Same for all the coolant hoses, heater hoses, etc. and rule out any possible coolant leaks before worrying myself sick about engine internals.

In the meantime, I'd monitor the coolant level weekly and pay close attenion to how much coolant was used, and under what conditions.

How many miles on the engine now?

[More Power]

When I first learned that the Duramax was equipped with a gear driven water pump about 6 years ago, I thought about a potential for coolant in oil.

I have heard of a couple instances of water pump seal failure and coolant in oil. For example, the editor of Diesel World magazine lost the engine in his 2002 Chevy because of this.

I'd do what Mark suggested, then make certain coolant wasn't getting in the oil. I also might be inclined to replace the coolant surge tank cap if you discover a leaky water pump seal. Too much pressure will increase wear on the WP seal.

Jim

[Mark Rinker]

Jim - great idea on the caps. Nobody even mentioned this to me at the dealership, and it seems likely that mine may be the source for the original pump seal failure (stuck closed), and possibly even the phantom coolant smells underhood since the water pump replacement (stuck open?)

Either way, two new caps will be ordered today for my '01 and '02 and both replaced.

[BozDMAX]

Mark - 121K on the clock, about 600 since they replaced the injectors. I will put it on the lift tomorrow and give everything a really good visual. I read up some on ALLDATADIY.com and I can certainly see now the WP seal issue and the cap pressure makes sense as well.

The loss of coolant troubleshooting list gives a good rundown of places to look for coolant loss, but I don't really see anything simple on it that might potentially leak to the block other than the water pump.

With the harmonic balancer removal requiring removal of the starter and special tool to clamp the flywheel, I am not certain I want to break into the thing to do the pump myself if I see it leaking.

Probably a good time to hit thermostats and hoses too. The oil I pulled yesterday shows no sign of coolant separating. I did notice while I was under there that the lowest part of the oil pan looks lower than the drain plug - meaning that there would always be several ounces at least that would never drain. Unless you drain your oil parked uphill at a 30 degree angle. Anyone else ever notice that?

[WILLYD-MAX]

Her are some oil analysis results. I switched to Amsoil 15w40 synthetic from Mobile 5w40 synthetic and sampled both just to see if thier was much difference.

Mobile 5w40 Synthetic 8271 mls. Amsoil 15w40 Synthetic 9589 mls.
Iron 14 Iron 12
Lead 2 Lead 2
Cop. 15 Cop. 16
Alum. 4 Alum. 6
Silv. 0 Silv. 1
Silicon 13 Silicon 12
Boron 35 Boron 8
Magn. 600 Magn. 141
Calcium 2685 Calcium 3431
Phosp. 1221 Phosp. 1238
Zinc 1595 Zinc 1507
Molybe. 0 Molybe. 7

Vis.@100 C 13.58 Vis.@ 100 C 14.13
Soot/Solids %Wt. 0.1 Soot/Solids % Wt. 0.1
TBN 9.01 TBN 9.19
Oxid. N/A Oxid. 6.0
Nitr N/A Nitr 7.0
F-Soot 0.14 F-Soot 0.03

Both samples were good for continued use. Anything look abnormal to anyone? I am planning on going 15k on the next one and posting my analysis. My miles are approx. 75% towing anywhere from 15k to 28k gross wt.

[BozDMAX]

Where do you send your oil for analysis?
Has the service been good?
What kind of turn-around times do you usually see and how do they inform you of results?

[WILLYD-MAX]

I buy the sample kits thru Amsoil, they use Oil Analysers Inc. This is my first time using them and it was kinda slow but I attributed it to getting my account set up and so on. They sent it by mail and they can also send via email. Once your setup and you enter a phone # if you send a sample in and it requires immediate attention a tech will call you directly.

[nlp]

Please comment on results from my 1st oil analysis
Done at a local CAT S.O.S. lab.
Oil is Shell Rotella T-Synthetic 5w-40 with 8450 miles w/ Napa Gold Filter
Truck is 2002 D/A, 100% stock, 91,350 miles, original injectors.
Wear Metals (ppm)
Al = 2 ppm
Ba = 0 ppm
Ca = 3323 ppm
Cr = 0 ppm
Cu = 3 ppm
Fe = 9 ppm
Pb = 4 ppm
Mg = 11 ppm
Mo = 1 ppm
Ni = 0 ppm
P = 1308 ppm
K = 4 ppm
Si = 7 ppm
Na = 4 ppm
Sn = 0 ppm
Zn = 1452 ppm

Oil Condition / Particle Count (ct/ml)
Soot = 0
Oxidation = 16
Nitration = 7
Sulfation = 21
Water = None
Antifreeze = None
Fuel = None
V100= Viscosity@100C = 14.1

[jbplock]

Excellent ! Very low wear metals.. Did they do the TBN test?

[More Power]

Iron (Fe) is the most prevalent wear metal in the engine. Chromium (Cr) and molybdenum (Mo) indicate piston ring wear. Lead (Pb), copper (Cu), and tin (Sn) indicate bearing wear/status. Aluminum (Al) is associated with piston wear. Nickel (Ni) typically doesn't exist as a wear metal.

Silicon (Si) usually represents dirt getting past your air filter. A single digit silicon level (like yours) is good.

Elements like magnesium (Mg), calcium (Ca), phosphorous (P) and zinc (Zn) are usually associated with engine oil additives.

A significant combination level of sodium (Na) & potassium (K) could be an indication of the presence of glycol.

Your numbers look good!

Jim

[phill0072]

Here is my oil analysis for my 06 express van with lly, this is the first oil analysis I have had taken for this unit, miles when taken 49727, miles on oil when sampled 9626 ALL LISTED IN PPM

IRON 12
CHROMIUM 0
LEAD 0
COPPER 14
TIN 0
ALUMINUM 2
NICKEL 0
SILVER 0
SILICON 12
BORON 0
SODIUM 0
MAGNESIUM 74
CALCIUM 3390
BARIUM 0
PHOSPHORUS 1191
ZINC 1359
MOLYBDENUM 0
TITANIUM 0
VANADIUM 0
POTASSIUM 0
FUEL <1%
VIS @ 100c 14.38
WATER 0
SOOT/SOLIDS .2% OF WEIGHT
COOLANT NONE

TBN 8.37 OIL IS 12 WHEN NEW AMSOIL 15-40 PART #AME
OXID 7.0
NITR 10.0
F-SOOT 0.23

I DID CHANGE THE OIL AT THE TIME THE SAMPLE WAS TAKEN PLEASE TELL ME IF I NEED TO WORRY ABOUT ANYTHING GOING ON IN THE ENGINE, I DON'T KNOW IF THIS IS GOOD OR NOT. THANKS FOR YOUR HELP IN ADVANCE!!!!!!!!!!!!!