02 GMC Yukon Denali Amsoil 0W-30 8000K HIGH COPPER

[srl1104]

This sample is from my Mom's 2002 GMC Yukon Denali. It sees quite a bit of short trips and a few highway miles. The oil was in service for about 8 months and 8000 miles. The oil was Amsoil Series 2000 0W-30. It is the older formula, two reformulations back. I am very worried about the high copper number that has shown up in this oil. Before the change to Amsoil, the engine was very quite and milage was above average. Since the change it has developed piston slap on startup which I originally thought was lifter noise, and the milage has dropped considerably from what it used to be(average of 5 mpg decrease). Any help would be appreciated.

Thanks,

Shane
EQUIPMENT MAKE: GM
EQUIPMENT MODEL: 6.0L 364 CI V-8
FUEL TYPE: Gasoline (Unleaded)
OIL USE INTERVAL: 8000 miles
OIL TYPE & GRADE: Amsoil Series 2000 0W/30
MAKE-UP OIL ADDED: 1.5 qts

SHANE: You mentioned lifter noise, which we would associate with upper-end wear (aluminum). But
copper stuck out like a sore thumb, so maybe that is related to the noise you're hearing. Copper tends
to show wear at a bronze or brass part, like a bushing. All the other metals are okay, but copper
probably shows a problem in your Yukon. No moisture, fuel, or coolant found. The air and oil filters are
working well. The TBN read 2.6, still some active additive remaining. 1.0 is low. We don't know how
long this oil was run but we'd suggest fewer miles on the next fill.

MI/HR ON OIL - 8000
MI/HR ON UNIT - 42000
SAMPLE DATE - 9-28-07

ALUMINUM - 4
CHROMIUM - 1
IRON - 27
COPPER - 184 (NOT A MISPRINT)
LEAD - 7
TIN - 0
MOLYBDENUM - 20
NICKEL - 2
MANGANESE - 1
SILVER - 0
TITANIUM - 0
POTASSIUM - 1
BORON - 23
SILICON - 12
SODIUM - 7
CALCIUM - 3141
MAGNESIUM - 15
PHOSPHORUS - 634
ZINC - 741
BARIUM - 0

TBN - 2.6

SUS
VISCOSITY @ 210 ºF - 60.1

FLASHPOINT IN ºF - 410

FUEL % -
ANTIFREEZE % - 0.0

WATER % - 0.0

INSOLUBLES % - 0.0

 

[Pablo]

I have a hard time believing any oil would cause a 5 mpg drop in gas mileage.

Cu can be very high in GM engines. What was the oil used before? What was the Cu level?

The oil didn't thicken - 60.1 is about 10.2 cSt, a little lower than starting, but no solids, high flash.

You probably need a bit higher viscosity oil in this engine. Try Amsoil DEO. DEO 5W-40
Or possibly ACD 10W-30

Consult with Terry Dyson and get the rig checked professionally.

 

[srl1104]

Quote:

---

I have a hard time believing any oil would cause a 5 mpg drop in gas mileage.

Cu can be very high in GM engines. What was the oil used before? What was the Cu level?

The oil didn't thicken - 60.1 is about 10.2 cSt, a little lower than starting, but no solids, high flash.

You probably need a bit higher viscosity oil in this engine. Try Amsoil DEO. DEO 5W-40
Or possibly ACD 10W-30

Consult with Terry Dyson and get the rig checked professionally.

---

Thanks Pablo,

I kind of worded it wrong in saying that the oil caused it. I am thinking that maybe the high copper and the milage drop may be connected

 

[benjamming]

absolutely 0 insolubles for 8k mile OCI? Unbelievable.

 

[Pablo]

Yeah - there is something going "GM" with this engine. I'm no SBC expert but it sounds like a cam retainer/pressure bushing - with Cu and Fe up.

What kind of oil filter?

 

[srl1104]

Quote:

---

Yeah - there is something going "GM" with this engine. I'm no SBC expert but it sounds like a cam retainer/pressure bushing - with Cu and Fe up.

What kind of oil filter?

---

Amsoil EAO

 

[Loobed]

Quote:

---

Yeah - there is something going "GM" with this engine. I'm no SBC expert but it sounds like a cam retainer/pressure bushing - with Cu and Fe up.

What kind of oil filter?

---

I think the 6.0 is a Big Block not small block.

I got my best milage in my 5.3 with Castrol 0W-30. I didn't do a UOA, so I dont know if there was any more wear then normal. Your (his) mailage could drop for several reasons. One is having the truck site for a long time so octane can evaporate through the plastic fuel tank. The lower octane will cause the engine to retard it's timing and give you poor milage. You may need to blow out the carbon from the cylinders. Women tend to be too easy on the motors, which isn't good.

Put some Techron or seafoam in the fuel tank, fill it up with premium fuel, then take it for a long ride on the highway at night with the cruise contrl set @ 65 mph. You need to keep the engine running at operating temps and RPM's for about an hour. A 100 mile stright run would be a good way to check the milage and clean the chambers.

 

[Hammer]

Quote:

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I think the 6.0 is a Big Block not small block.

---

It's a Gen-III Small block. Even the LS7 427 is a small block.

Hammer

 

[Pablo]

Quote:

---

Quote:

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Yeah - there is something going "GM" with this engine. I'm no SBC expert but it sounds like a cam retainer/pressure bushing - with Cu and Fe up.

What kind of oil filter?

---

Amsoil EAO

---

That would maybe explain the low solids. Perhaps a good combustion chamber cleaning will help with the MPG. Try a run with ACD 10W-30 and see how the wear metals do.

 

[Jim 5]

For my money, I would pay Terry Dyson to have a look at this UOA and pay his modest fee for his advice. Many of us pay for this service with wear numbers at 1/10th these levels and still feel we got good value.

 

[Steve S]

In all honesty with the uoa in hand go to a trusted repair shop or a good dealer ,loosing 5 mpg is serious keep us informed so we can learn.

 

[SargeGTO]

It is a short block guys....I run a few of them....the Amsoil 0-30 gave me really high copper readings also.....I got off that stuff quick.....I recommend either Amsoil 10-30 or PP 10-30....

 

[srl1104]

Before I received the UOA back We already had filled it with the Amsoil 5W-30. I hope this was a step in the right direction because a couple of you have mentioned trying the 10W-30. What is it about the 10W-30 over the 0W-30 or 5W-30 that you guys feel would reduce the wear numbers?

 

[Steve S]

Quote:

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It is a short block guys....I run a few of them....the Amsoil 0-30 gave me really high copper readings also.....I got off that stuff quick.....I recommend either Amsoil 10-30 or PP 10-30....

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I dialed in on the 5 mpg loss and the noise.

 

[Steve S]

Try a different oil first .

 

[Pablo]

Quote:

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Before I received the UOA back We already had filled it with the Amsoil 5W-30. I hope this was a step in the right direction because a couple of you have mentioned trying the 10W-30. What is it about the 10W-30 over the 0W-30 or 5W-30 that you guys feel would reduce the wear numbers?

---

Nothing scientific really other than saving you some money until you get your engine sorted out. However, I don't see that engine needing a 0W-30, PLUS an SAE 30, such as Amsoil ACD (10W)-30 will produce lower wear in a well running engine.

BUT - 5 MPG loss has nothing to do with which 30 oil you choose!

 

[cfromc]

I posted a UOA on this stuff 4/28/07 and only had 9 Cu, but at almost 10K miles, the TBN was 1.0. I did not notice a 5MPG loss but I did seem to have a little less MPG with this oil, instead of the (slight) gain in MPG I was expecting. I also noticed more noise from the engine. I still have 10 quarts of it that I have to figure out what to do with since I've now switched to a 10W-30 with good results. Perhaps the copper is coming from an oil cooler? Or maybe it was a fluke. Or possibly the TSO was doing some cleaning? I would definitely get another UOA at the next OCI.

 

[Mike_dup1]

If only the copper is high, but no other metals such as lead, tin, or aluminum are elevated, it is mostly an oxide of copper from the oil cooler. As the oil cooler is exposed to the heat from the engine oil, it can sometimes oxidize the copper, which will show up in the analysis report. This is considered a normal condition and no corrective action is required. This process usually will taper off or stop occurring over time.