Amsoil SSO/AMO, 11.2k miles, 08 GMC Acadia 3.6L

[jetman]

This is the wifes car. She changed jobs 3 mths ago. It now does a daily commute of 40 country miles. It will get approx 20k miles/yr. In the future, I expect the oil and ff filter to go 15-20k between changes.

This run was a blend of 2 qts Amsoil SS0 0-30w and 4 qts AMO 10-40w. The full flow filter was a Fram XG2. Bypass setup was the same, a TopDog V w/Amsoil EaBP90. Air cleaner element was the same a STP brand w/29k miles on it now.

I've looked for induction system leaks, I can't find any? The silicon doesn't appear to be hurting anything. I'm gonna change the air filter element to a Fram now.

I'm not going to change the oil until the end of Oct because of the life left in it. At that time I'll install 6 qts of Amsoil AMO 10-40w, a Fram XG2 full flow filter, and a new EaBP90 bypass filter. The bypass filter has been in place since 1/11 and has 27k miles on it.

The engine doesn't use any oil, so no makeup oil was added.

The first #s the oil had 9k on it and wasn't changed.
The second #s the oil had 14.3k on it and it was changed.
The 3rd #s the oil had 12.5k on it and the oil was changed.
The last(most recent) #s the oil had 11k on it and like I said, the oil won't be changed until late Oct. Until this latest run, the oil has always been 100% SSO 0-30w. Total miles on vehicle now is 80k miles. Except for a water pump, it's been a trouble free vehicle.

Code:


WEAR METALS-PPM

Iron 20....42....25....21

Chromium 0......0....0......0

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

Tin 0......0....0......0

Lead 0......0....0......0

Chrom 0......0....0......0

Nickel 0......0....0......0

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

Silver 0......0....0......0

Cadmium 0......0....0......0

Vanadium 0......0....0......0

CONTAMINANT METALS-PPM

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

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

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

MULTI SOURCE METALS

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

Titan 0......0.....0....0

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

Antim 0......0.....0....0

Lithium 0......0.....0....0

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

ADDITIVE METALS-PPM

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

Calcium 3115..2949..3269..3976

Barium 0......0.....0....0

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

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



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

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

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

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

Fuel
Soot Vol

 

[barlowc]

Iron seems high. Especially that one sample where it was 42. But I guess if you're running the oil twice as long as many others, (roughly) twice the iron probably isn't indicative of any problems or all the surprising.

 

[chubbs1]

Looks like a fine report. Silicon is the only thing a little high but as you said it doesn't appear to be hurting anything. Iron is consistent so I would not worry about that, sodium is not an additive in the oils you are using so that coolant would be the only thing I would watch for.

Great stuff! thanks for the post!

 

[buster]

Looks really good to me.

 

[webfors]

Good report. What's the with high Si? Are these engines known for high'ish silicone?

Is that TBN right @ 8.01 after 11k+ miles?

 

[Brons2]

Sodium and potassium are worrisome. Coolant ingestion?

Wear metals look great though, so if there is a coolant leak of some sort, it's not causing any trouble. Yet.

Keep an eye on your coolant level!

 

[jetman]

Originally Posted By: webfors
Is that TBN right @ 8.01 after 11k+ miles?

No, 9k miles, and this was before the bypass system was installed and I was installing a new full flow filter and the make-up oil thats lost when changing it. The plan pre-bypass system was to go 25k miles between oil changes w/2 filter changes in between.

 

[jetman]

Originally Posted By: Brons2
Sodium and potassium are worrisome. Coolant ingestion?

Wear metals look great though, so if there is a coolant leak of some sort, it's not causing any trouble. Yet.

Keep an eye on your coolant level!

The lab isn't worried?

 

[jetman]

Originally Posted By: chubbs1
Silicon is the only thing a little high but as you said it doesn't appear to be hurting anything. Great stuff! thanks for the post!

I went to change the air filter element today, and low and behold, what did I find? The induction leak and the source of the Silicon. For some reason? the air box doesn't clamp down on the perimeter of the air filter element enough to create a good seal. Unfilter air has been getting around it. Can you see all the dust on the wall of the air box near the perimeter in the pic below?

So I installed some wx stripping to the perimeter of the air box so as to make a good seal(see pic below).

I should know in about a yr when we do the next UOA if this did the trick.

 

[Pablo]

That's really quite an engineering flaw. Have you checked other Acadias/online to see if it's supposed to have a seal? Nice fix on your end.

 

[webfors]

Nice catch! That's a lot of dirty air getting in, so that makes this report even hotter. I bet your bypass helped with that.

What air filter was used that didn't have the thickness to get a good seal? Or is it really the box itself with a poor design?

 

[OVERKILL]

I'm interested to hear what brand of filter was being run and if that is a contributor here.

 

[jetman]

Originally Posted By: OVERK1LL
I'm interested to hear what brand of filter was being run and if that is a contributor here.

Reference the Si data in my OP. I have no idea what brand air filter was in place for the 1st UOA, but it was in place for 9k miles, maybe more, don't know. The last three UOAs and 29k miles an STP brand was in place. I know I have loosen and retightened the top of the air box since putting in the STP filter, looking for an air leak. But I've never had the top of the air box completely out because I would never expect a problem at the perimeter seal on any brand of air filter. Somebody here on the forum once warned that there are wires and vacuum lines that could accidently get between the 2 halfs of the air box when changing the air filter element causing an air leak, so I've been careful and watched out for this. Anyway, I'm not taking any chances with any brand filter, so I installed the wx strip. I've posted all this info on the Acadia forum, and nobody has said anything(yet) about a missing factory seal?

 

[LargeCarManX2]

Just a late thought, but the airfilter element or panels rubber edge should have sealed the edges. Will the new wx strip prop the filter up too high? I often coat the rubber edge of the filter with grease to help with the seal on this type of air box.

 

[jetman]

Originally Posted By: LargeCarManX2
Just a late thought, but the airfilter element or panels rubber edge should have sealed the edges. Will the new wx strip prop the filter up too high?

I dom't believe so, it crushes completely and the air box went back together perfectly.

 

[jetman]

Both the old STP and the new Fram have perimeter seals on both sides? Maybe the seal was/is too flimsy for the amount of vacuum it must control?

It has to be something I did incorrectly. Maybe I didn't have the screws tightened all the way, or didn't have the top aligned perfectly with the bottom? I can't imagine this being a factory flaw on GMs or the filter makers part.

Oh well, mystery solved and fixed I hope. Here a pic of the edge of the old STP filter

 

[aussiek2000]

FWIW as a GM tech I have seen a few different filters in these vehicles. I have noticed that the STPs have a thinner,harder rubber seal than the ACDelcos.