Amsoil AMO 10-40w, 13k miles, 08 Acadia 3.6L

[jetman]

Code:


Date of UOA 12/10 5/11 2/12 9/12 5/13

Miles on oil 9k 14.3K 12.5K 11K 13K

WEAR METALS-PPM (no #s = all zeros)

Iron 20............42...............20................21...............19

Chromium

Copper 7.............7................5..................4................5

Tin

Lead

Chrom

Nickel

Alum 5.............6.................5..................7...............2

Silver

Cadmium

Vanadium 0............0..................0..................0...............2

CONTAMINANT METALS-PPM

Silicon 42...........50..............64.................65.............50

Sodium 15............27..............22................28..............39

Potassium 3............3................4.................4..............6

MULTI SOURCE METALS

Manganese 3............3................1.................1..............0

Titan

Molybdenum 10...........8................4.................3..............3

Antim

Lithium

Boron 9............7................7.................4..............1

ADDITIVE METALS-PPM

Magnesium 12...........12...............13................13............13

Calcium 3115..........2949.............3269..............3976.........3575

Barium

Phosph 542.............554.............588................861.........964

Zinc 627.............642.............613................1039.......1249



V100C 10.1............10.4.............10.1...............12.0........13.0

Oxidation 44...............63...............72................71...........77

Nitra 35...............42...............47................22...........23

TBN 8.01............1.72.............1.67..............3.84.........0.98

Fuel
Soot Vol

This is the wifes car. She does a daily commute of 40 country miles. It gets about 20k miles/yr.

The oil is 6 qts of Amsoil AMO 10-40w with 13k miles(9 mths) on it. The full flow filter is a Fram XG2. Bypass setup is the same TopDog V w/Amsoil EaBP90 filter that was changed at the last oil change.. Air cleaner element was changed to a Fram at the last oil change. The engine doesn't use any oil. No makeup oil was added.

Last November, about 10k miles ago, the check engine light(CEL) came on and the car was hard to start after filling up w/gas. AutoZone pulled the code, P0496. I replaced Canister Purge Valve Solenoid w/AcDelco #214-1685, $31. There haven't been any issues since then. I ocassionally drive the car and have noticed that the gas mileage since then has decreased from 19.9mpg to 18.7mpg. It is obviously running rich. It runs great and no CEL or codes.

IMO, there isn't any abnormal wear ocurring because of the bypass. I sure wish I could find the induction leak. It doesn't use any coolant.

Could the fuel in the oil be left over from when the purge valve solenoid went bad 10k miles ago?
Could the higher viscosity oil be causing the fuel dilution? (Variable Valve Timing?)
Or, could it be a bad MAP or O2 sensor?

Thoughts

 

[Barkleymut]

I really doubt the fuel could be from 10K miles ago, I cannot wait to see what the oil gurus say. Just wanted to comment so I can track this interesting UOA

 

[Turk]

Silicon seems high, change the air filter and/or check for air leaks.

 

[Pablo]

Originally Posted By: jetman


IMO, there isn't any abnormal wear ocurring because of the bypass. I sure wish I could find the induction leak. It doesn't use any coolant.

Could the fuel in the oil be left over from when the purge valve solenoid went bad 10k miles ago?
Could the higher viscosity oil be causing the fuel dilution? (Variable Valve Timing?)
Or, could it be a bad MAP or O2 sensor?

Thoughts


This is one of the longer UOA's seen on this engine. And I agree, the wear is VERY nice.

Fuel at 3.7% is a problem. Oil vis starts at 14.5 and the high fuel just crushed the TBN. It's possible you have a faulty component. Is there no way to reset the fuel map or is there some worry of going lean?

The high Si also is kind of a bugger. I would really check the whole fuel and induction system. Is there an Acadia board?

 

[Clevy]

Looks pretty good for the miles. Had tbn not been affected by the fuel dilution I suspect you could go much longer on the oil.
Looks good on Amsoil for keeping wear rates low even though the fuel dilution kinda killed it.

 

[jetman]

Originally Posted By: Pablo
This is one of the longer UOA's seen on this engine. And I agree, the wear is VERY nice.

Fuel at 3.7% is a problem. Oil vis starts at 14.5 and the high fuel just crushed the TBN. It's possible you have a faulty component. Is there no way to reset the fuel map or is there some worry of going lean?
I need to change the oil,filter, and spark plugs, so while I'm at it, I'll disconnect the battery which should reset the ecm, and look for any abnormalities.

Originally Posted By: Pablo
The high Si also is kind of a bugger. I would really check the whole fuel and induction system.
I've looked and tried various things for 3+ yrs without success.

Originally Posted By: Pablo
Is there an Acadia board?
Yes, I post there, but their not a bunch of rocket scientist (like we have here), if you know what I mean.

 

[Rat407]

Isn't sodium a little high or am I missing something? This looks like what mine might be like if I let it in for that long and I change out at 5k miles. Only difference is mine is a DI engine. I posted my latest UOA but no comments so it must not be anything out of the norm.

 

[jetman]

Originally Posted By: Rat407
Isn't sodium a little high or am I missing something?

The lab didn't think so. The lab flagged my: Silicon,fuel dilution,TBN, and oxidation.

Originally Posted By: Rat407
This looks like what mine might be like if I let it in for that long and I change out at 5k miles. Only difference is mine is a DI engine. I posted my latest UOA but no comments so it must not be anything out of the norm.

My oil had 2.6 times the miles of yours(13k vs 5k). Multiple your wear metal #s(alum,iron,copper) times 2.6 and your #s are twice as high as my #s.

 

[jetman]

Originally Posted By: Pablo
Is there an Acadia board?
Yes, I post there, but their not a bunch of rocket scientist (like we have here), if you know what I mean. [/quote]

I mis-spoke. Sorry! The Acadia forum folks probably ARE a bunch of rocket scientists, but they don't think outside the box much. They are the type that refers to the owners manual for all decisions .

 

[jetman]

Originally Posted By: Barkleymut
I really doubt the fuel could be from 10K miles ago, I cannot wait to see what the oil gurus say. Just wanted to comment so I can track this interesting UOA

I think it is from when the cannister fuel solenoid went bad and fuel ended up in the crankcase.

 

[jetman]

Originally Posted By: Turk
Silicon seems high, change the air filter and/or check for air leaks.

I've done both, and more, a few times.

 

[jetman]

I changed spark plugs. They looked good for 94.5k miles(see pics below). I also pulled the induction system apart again and looked for a leak again. I didn't find anything definitive. The wx strip I installed in the air filter box 9 mths ago, at the last oil/filter change, is doing what I hope. There is NO sign of any air getting by it now. I cleaned the MAF sensor. Next, I got some black silicone sealant and sealed 2 areas where GM bonded two different materials together(see pics below). I also replaced an o-ring with a silicone gasket where the MAF sensor tube joins the air filter box.

I think the decrease in gas mileage was caused by the use of 10-40w oil, GM recommends 5-30w. 10-40w too thick for the Variable Valve Timing system that this engine utilizes. I'm gonna change to Amsoil ACD 10-30w and retest in 9 mths.

Time will tell?

 

[Ibrahim]

You need to address your Fuel Dilution issue asap, no doubt about that. Well, you have changed the Spark Plugs, let see if that helps. You car is running rich, does it need to be re-programmed? Also taking out on a long hwy drive once a while helps!

Keep a close eye on Silicon as well.

 

[Brons2]

3.7% fuel, but viscosity is still 13.0, in the 40 wt range. The engine is spec'd for 5w30. Obviously the amount of fuel is non-optimal but it didn't hurt wear numbers.

 

[jetman]

I'm also starting to think that there is, and always has been, a little bit of coolant finding its way into the oil causing the somewhat elevated Si #s. So I'm putting some Bar's Leak in the cooling system. I'm gonna put a load of dino 5-30w and a OCOD for a few tanks of gas to flush the gunk out.

If my avg mpg returns to nornal(19.5 mpg), then I'll put a load of Amsoil ACD 10-30w w/an XG2 filter and do another analysis in about 13k miles.

 

[WINO]

Why the use of an oil not called for? 10w-40 vs 5w-30? courious

 

[2James1]

Originally Posted By: WINO
Why the use of an oil not called for? 10w-40 vs 5w-30? courious


I'm thinking it's because of the fuel dilution issues with direct injection.

 

[Clevy]

Originally Posted By: Brons2
3.7% fuel, but viscosity is still 13.0, in the 40 wt range. The engine is spec'd for 5w30. Obviously the amount of fuel is non-optimal but it didn't hurt wear numbers.


It seems that way doesn't it.
I wonder if the OP ran the specified 30 grade would the fuel dilution have led to higher wear numbers.
It is certainly difficult to speculate considering we would be just guessing however perhaps using the 40 grade adds a bit of headroom in that department.
Just spitballing