2009 Silverado, 3772mi, PP 5w30 SM, OLM 55%

[dave2009]

I stitched to PP this run and did not use the remote start but the lead continues to increase and now Tin is up as well. I had wanted to stretch the OCI out to 6K and based the many posts on BITOG, both PP and PYB are very good oils. I'm thinking about switching back to Castrol GTX or possibly something else because the UOA was much better on GTX, even on a new engine. Vehicle is 2009 Silverado Crew Cab 5.3L with AFM. 75% Highway driving. Please help! Thanks

Blackstone Comments: Unfortunately, we still can’t recommend 6,000 miles on the oil. Most of the wear metals look good but lead and tin are considerably higher than average. Than means that this 5.3L is seeing some excessive bearing wear. This level might be normal for this engine and the use that it sees, but until we know that for sure, stick with 3,000-4,000 miles on the oil. Fuel at 1.0% isn’t cautionary and the viscosity was normal for 5W/30. The TBN was strong at 4.6 showing lots of active additive remaining. Hopefully the bearings look better the next time.

/PP / /PYB /GTX
MI/HR on Oil /3,772 /Unit Avg /2956 /3135
MI/UR on Unit /23,771 / /19,999 /4843
Sample Date /05-04-2011 / /02-20-2011 /05-07-2010
Make Up Oil Added /0 /0 /0

Aluminum /2 /3 /3 /3
Chromium /1 /1 /1 /1
Iron /10 /13 /9 /19
Copper /49 /93 /40 /190
Lead /27 /20 /24 /10
Tin /8 /5 /3 /3
Molybdenum /74 /108 /246 /5
Nickel /1 /1 /1 /1
Manganese /1 /3 /1 /6
Silver /0 /0 /0 /0
Titanium /0 /0 /0 /0
Potassium /0 /1 /0 /3
Boron /14 /29 /69 /4
Silicon /13 /16 /12 /23
Sodium /4 /93 /5 /269
Calcium /2411 /2272 /2267 /2139
Magnesium /10 /8 /7 /7
Phosphorus /693 /695 /717 /675
Zinc /705 /782 /779 /863
Barium /0 /0 /0 /0
Values
should be
SUS Viscosity @210F /56.3 /56-63 /54.3 /55.8
cSt Viscosity @100C /9.15 /9.1-11.3 /8.58 /9.00
Flashpoint in F /345 />365 /375 /400
Fuel % /1.0 / Water % /0.0 /0.0 /0.0
Insolubles % /0.4 /0.2 /0.3
TBN /4.6 /4.3

 

[genynnc]

I'm not great at reading these. From my amateur observations, GM V8's are certainly 'weird' or *appear* to be with regards to their UOA signatures.

Some shed iron at higher levels than your for many miles/ years. Some don't. Some appear to break in rapidly, some don't and show some elevated levels of wear to 30-40K.

I don't think the report looks bad but it doen't look great.

Your insolubles seem to be a little bit elevated, I think .3 is about average(?). Fuel also seems relatively high.

I raise the question of the AFM here. Does the dropping of cylinders cause excess bearing loads here (somewhat lugging at lower rpm which would be highway speeds just over X mph where the AFM kicks in?) You run a lot of highway so I guess you are in AFM quite a bit?

I'm sure someone else here knows the GM LSx series better and understands the AFM better and therefore can address your UOA plus my question accurately.

 

[WANG]

Hmmm. My PP UOA in my G8 GT (6.0L L76 AFM engine) had a lead value that was a little higher than you usually see, too. I'll send in a sample again when I wear this load of PU out. Is this just a characteristic of gen IV v8s?

 

[dparm]

What is this car spec'd for at the factory? (OCI and type of oil)

 

[dave2009]

GM specifies 5w/30 and change per OLM or at least yearly.

In regards to when the AFM is in 4-cyl mode the engine is under a light load, level grade and light pedal. It almost never sees 4-cyl on the hwy when driving @75.

 

[ChiTDI]

The Sodium history shows when you used the Castrol GTX, but the wear metals are tough to trend.
Do you periodically tow?
The insolubles and fuel dilution raise an eyebrow.

 

[Brian Barnhart]

As I said in comments to your previous UOA, I believe much of your wear is due to fuel dilution. And I don't trust the accuracy of this particular lab's fuel dilution numbers.

The best way to combat fuel dilution is by keeping the engine in top running condition. By that I mean periodic use of good fuel cleaners (at least 2 or 3 times a year), the use of top tier fuels (which you apparently have been doing), and keeping a clean element in the air cleaner (change once a year). Avoiding long idling periods will also reduce fuel dilution (if applicable).

I have a 2006 5.3 in my truck. I have had two UOAs performed on it and they both came back fairly good. But I believe the later 5.3s like yours have a greater tendency toward fuel dilution.

If you want to change the oil brand/type, I would go back to GTX or consider Valvoline (which is what was in my UOAs). But IMHO, the root of the problem is fuel dilution and changing to another OTC oil isn't likely to make much difference.

 

[dave2009]

No I don't tow. However, this truck drives like I'm pulling something all the time. It downshifts quite a bit on the hwy driving @75 when there is a slight hill. Could be all the wind I always seem to be fighting when driving. I can't wait for my custom tune from Blackbear. From everything I've read the tune will help tremendously.

 

[dave2009]

I do tend to agree about fuel dilution, even though I can't prove it, is causing problems. This theory is just based on how it drives and the relative poor hwy mileage. I read somewhere that GM runs the engine richer to aid with cooling. Don't know if that is true but maybe the tune would help with that as well

 

[YZF_Eric]

246 of moly in PYB? Did I read that correctly?

 

[dave2009]

Yes, that moly number is correct.

 

[INDYMAC]

I agree that fuel dilution is probably the issue, but difficult to correct. That being said, you might want to switch to a different brand of fuel (Chevron to Shell, or vise versa) to eliminate an additive conflict with the bearings. Blackstone recommended this to me once, and it worked. Also, if you use a concentrated fuel system cleaner. try to complete the cleaning cycle just before an oil change. That way, you will have those additives in the sump only for a short period of time.

Thanks for posting this UOA. I just changed the oil on my daughter's 2008 Avalanche yesterday. I saved a sample of Valvoline WB 5W-30 SN/GF-5 to send to Terry Dyson. It will be the first look at this engine with 55K miles.

 

[addyguy]

Slicon, insoluables, and fuel are all elevated, that is what is causing the high wear.

Check your air filter, and the ducting to the air filter for leaks to start. Use a 'cheap' 5W-30 oil, and change every 3k for a while to flush the dirt out.

Hopefully, it will look better after that.

 

[bigmike]

dave2009,
Just out of my own curiosity - What oil filter are you using?

 

[dave2009]

Purolator PureONE oil filter.

 

[pcfxer]

PP is nothing special...it is another entry-level "synthetic" available over the counter. That said, you are still below average and so if you extend beyond 'average' you will have above 'average' (that isn't a bad thing).

Just because you measure lead and tin also does not concretely mean you DO have bearing wear (you always do actually...) or not, but that you have a particular level of lead and tin in your sample.

If this is your first use of PP, I wouldn't worry about it. Viscosity and TBN are good, expect higher wear simply from increasing intervals.

 

[chubbs1]

Unfortunately there is some fuel getting in the oil. There is the problem, most oils will have a hard time fighting that. It is odd that with as much Highway driving you do there is dilution. The Flashpoints of the oil keep getting lower. 345F is quite low for PP, which is a good oil.

 

[FZ1]

Try M1 EP. Seems more durable in my Honda V6.

 

[genynnc]

Originally Posted By: chubbs1
It is odd that with as much Highway driving you do there is dilution.


Exactly my thoughts. Fuel, given this environment, should be lower or non-existent. Thus my suspicion of the AFM... but OP said AFM is hardly ever active.

 

[Turk]

Originally Posted By: FZ1
Try M1 EP. Seems more durable in my Honda V6.


Careful!! M1 EP was shot in another UOA forum here........