Amsoil SS 5w30, 10K, 04 Chevy Tahoe, 206K

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The lead trend is starting to make me worry that this engine isn't long for this world. We bought this one in 2011 with 129K miles on it and silicon has never read low, although Blackstone down plays it because metals are usually looking good. We did some towing on the 6.29.15 sample which helped explain/excuse why the lead spiked higher, but did no towing at all on this last interval.

I've replaced the air intake box on this one as it tends to trip the MAF, so I was assuming some dirt really WAS getting into the intake system. The MAF tripped twice on this last oil interval. I even had the rest of the air intake tubing off and hit it with some silicon spray in case there was some pinhole that I couldn't see, but silicon wasn't down very much on this sample. With the engine wear and mileage on the oil, would it be worth replacing the factory air system all together in favor of something like an after market system from SLP/K&N/etc? We were planning on trying to keep this one for maybe a couple more years, wife really wants a new Jeep...

Make/Model: GM 5.3L V-8
Vehicle: 2004 Chevy Tahoe

Code:


OIL Ams SS Ams SS Ams SS Ams SS Ams SS Ams OE

MILES IN USE 10,045 9,037 9,246 8,124 6,069 3,165

MILES ON UNIT 205,764 195,719 186,682 177,436 175,381 169,312

SAMPLE TAKEN 7/15/16 12/14/15 6/29/15 11/30/14 10/23/14 6/23/14

MAKE UP OIL 0 0 0 0 0 0



ALUMINUM 4 3 4 3 2 2

CHROMIUM 1 0 0 0 0 0

IRON 15 11 12 9 7 3

COPPER 11 12 10 12 10 6

LEAD 22 13 30 7 6 2

TIN 0 0 5 0 0 0

MOLYBDENUM 130 143 160 144 139 68

NICKEL 1 2 1 0 1 0

MANGANESE 0 1 0 0 0 0

SILVER 0 0 0 0 0 0

TITANIUM 0 0 0 0 0 0

POTASSIUM 2 4 4 0 0 0

BORON 42 36 61 45 53 105

SILICON 30 35 28 31 25 14

SODIUM 11 10 9 9 8 3

CALCIUM 2928 3570 3461 3247 3475 1944

MAGNESIUM 13 17 14 12 15 8

PHOSPHORUS 558 655 627 702 658 658

ZINC 628 773 800 801 767 747

BARIUM 0 0 0 0 0 0



SUS @ 210F 68.8 66.0 62.6 64.6 63.8 58.7

Visc @ 100C 12.64 11.88 10.94 11.51 11.29 9.86

Flashpoint 400 410 420 430 435 410

Fuel %
Antifreeze % 0.0 0.0 0.0 0.0 0.0 0.0

Water % 0.0 0.0 0.0 0.0 0.0 0.0

Insolubles % 0.5 0.3 0.2 0.4 0.3 0.1

TBN 2.2 3.3 3.3 3.1 3.4 2.4


Blackstone Inc Comments:
Lead is back up in this report. It's possible that this is another harmless event like a particle streak, or maybe we are actually seeing some excess bearing wear. It's hard to be sure because the rest of the wear metals are in great shape for the interval, and lead dropped back down in the last report. That's not typically the trend we see when there's excess bearing wear, so for now, as long as oil pressure is okay and you aren't hearing any unusual noises, we wouldn't worry too much. The thick viscosity is okay and the TBN was strong as 2.2, but use 10K miles or less.
 
Currently I would not worry too much about lead. I suspect that it is related to a season. Take a look: last sample was in use during a winter, same as third (6/29/15). Both of them has high lead, whereas 2nd and 4th (from the left, summer) are OK. May be it is worth to idle at winter a little bit longer before driving. But again, lead level is still OK.
Ha, I just paid attention that you are from TX. I don't know you climate, but still could be related.
And one more thing: I would not exceed 9k miles OCI, when TBN is still 3.3. I am a stong believer that oil should be changed when TBN a little bit lower than TAN. If TBN is 3 or less, TAN is usually above 4.
 
Could there be another element that appears to be lead in a UOA? Something that's part of the oil maybe?

There was someone using redline lately who also got high lead readings, but I'm not convinced that's what we're actually seeing. Anyway, switching to Mobil 1 solved his high lead problem which makes me think even more it's something from the oil.
 
Be careful shooting silicon spray near intake!! You can kill oxygen sensor, even catalytic convector, very quickly. Do a search with "silicon" and "O2 sensor" and you will understand what I mean.
 
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Hadn't thought of it not really being lead, guess that could be an option. I've used the same oil for a while, if the last 2 or 3 were consistent I would think it would be more likely. The fact that I've gone one OCI in between and lead improved, I'm not so sure.
 
You can trip the MAF sensor code when it thinks it's dirty even just a little. Spraying anything in the air ducts can add to a coating on the MAF.

Some MAF can be cleaned with a spray only, never touch any elements inside with fingers or tools. Then let dry real good, if the MAF is turned on when wet, the hot wire element can blow as it overdrives to vaporize the cleaner then it over- temps and is damaged.
 
I can't tell you whether that engine is about to let go. I can tell you that the 5.3 in a former work Tahoe seized while running down I-15 at a roughly similar number of miles as yours. It was maintained properly through its life up to that point.
 
Originally Posted By: bulwnkl
I can't tell you whether that engine is about to let go. I can tell you that the 5.3 in a former work Tahoe seized while running down I-15 at a roughly similar number of miles as yours. It was maintained properly through its life up to that point.

Why? Did you find the reason? It could not be "just because".
 
I'd back off your intervals considerably. Silicon is elevated, Insoluables are elevated, and viscosity is up a LOT on an oil that doesn't usually thicken in under 15k.

You are 'stressing' this oil a lot; and wear is suffering...the engine is full of dirt.

I'd move to OE 5W-30, and do a few 3-4k changes to see if you can flush the dirt out. The current regime is not doing the engine ANY favours.
 
addguy, overall the metals actually look really good. Lead is the one exception. I tend to agree with Blackstone that if the silicon was really abrasive dirt, the wear metals would be higher. I'm not 100% sold on that theory though, thus the reason I was asking thoughts regarding switching out the air intake system entirely in favor of an after market unit to ensure there is no dirt seeping in from somewhere.

I also reached out to Amsoil regarding the thickening of the oil and concern over the two flagged lead readings by Blackstone. They seem to believe the lead readings are still relatively low for this engine type and should be no cause for alarm. Below is their response:


Thank you for sending your oil analysis report. I have reviewed many Blackstone Lab reports and have found that their test results are very comparable to ours, but their interpretations can vary.

For example, while they highlight Lead levels of 22 and 30, they are vague about what that means and only give you a “universal average” of 6 ppm to compare your results to. Because a “universal average” is of dubious value, we construct a template for wear metal levels found for each specific type of engine once we receive 75 samples of oil for that unit. These templates are reviewed and updated yearly.

For the GM 5.3L engine, we would flag Lead as Severity 1 (upper half of the normal range) at 29 ppm. We would not flag Lead at Severity 2 (start of abnormal range) until 44 ppm. Accordingly, only your worst test result for Lead at 30 ppm would even be flagged for the upper half of the normal range.

Oil will also thicken with use unless it is being diluted with fuel. Most labs do not become concerned with a change of one viscosity grade (and yours is barely above the 12.5 cSt lower limit for 40 weight oil) unless contamination is suspected, such as from soot or coolant. Blackstone confirms this with their Comments.

Typically we find that in a properly running engine, the oils TBN will be the limiting factor in how long the oil can be used. After reviewing your test results, I believe that unless something unusual takes place, this will be the case for you as well.
 
Originally Posted By: timeau

Why? Did you find the reason? It could not be "just because".


Well, actually, it can and it was. The engine just gave up. We only did a partial tear down, but it was just all done. Reasonably clean, just all done.
 
Originally Posted By: dhellman12
addguy, overall the metals actually look really good. Lead is the one exception. I tend to agree with Blackstone that if the silicon was really abrasive dirt, the wear metals would be higher. I'm not 100% sold on that theory though, thus the reason I was asking thoughts regarding switching out the air intake system entirely in favor of an after market unit to ensure there is no dirt seeping in from somewhere.

I would not even consider switching out OEM air intake system..... due to 'poor' conditions of oils in use.

Quote:
I also reached out to Amsoil regarding the thickening of the oil and concern over the two flagged lead readings by Blackstone. They seem to believe the lead readings are still relatively low for this engine type and should be no cause for alarm.
Below is their response:
Thank you for sending your oil analysis report.
Oil will also thicken with use unless it is being diluted with fuel. Most labs do not become concerned with a change of one viscosity grade (and yours is barely above the 12.5 cSt lower limit for 40 weight oil) unless contamination is suspected, such as from soot or coolant. Blackstone confirms this with their Comments.

I beg to differ from Amsoil's expert interpretation in this particular case ....... never mind the fact that Amsoil (should) knows best about oils blended by them.
Assuming virgin KV@100*C of 10.4 cSt,the used oil viscosity of 12.64 cSt has thickened by upto 22%,clearly indicating an advanced/severe state of oil oxidation phenomenom.
I would reduce OCI, or consider switching oils, not OEM air intake syatem.
JMHO
blush.gif
 
Originally Posted By: zeng
Originally Posted By: dhellman12
addguy, overall the metals actually look really good. Lead is the one exception. I tend to agree with Blackstone that if the silicon was really abrasive dirt, the wear metals would be higher. I'm not 100% sold on that theory though, thus the reason I was asking thoughts regarding switching out the air intake system entirely in favor of an after market unit to ensure there is no dirt seeping in from somewhere.

I would not even consider switching out OEM air intake system..... due to 'poor' conditions of oils in use.

Quote:
I also reached out to Amsoil regarding the thickening of the oil and concern over the two flagged lead readings by Blackstone. They seem to believe the lead readings are still relatively low for this engine type and should be no cause for alarm.
Below is their response:
Thank you for sending your oil analysis report.
Oil will also thicken with use unless it is being diluted with fuel. Most labs do not become concerned with a change of one viscosity grade (and yours is barely above the 12.5 cSt lower limit for 40 weight oil) unless contamination is suspected, such as from soot or coolant. Blackstone confirms this with their Comments.

I beg to differ from Amsoil's expert interpretation in this particular case ....... never mind the fact that Amsoil (should) knows best about oils blended by them.
Assuming virgin KV@100*C of 10.4 cSt,the used oil viscosity of 12.64 cSt has thickened by upto 22%,clearly indicating an advanced/severe state of oil oxidation phenomenom.
I would reduce OCI, or consider switching oils, not OEM air intake syatem.
JMHO
blush.gif



Nothing to worry about. Amsoil's 0/5W-30 grades tend to thin then thicken rather then thin stay thin over extended OCI's. 2 PPM of lead for 1K miles is not a indication of impending doom.

http://www.bobistheoilguy.com/forums/ubbthreads.php?ubb=showflat&Number=3199010
http://www.bobistheoilguy.com/forums/ubbthreads.php?ubb=showflat&Number=2921239
http://www.bobistheoilguy.com/forums/ubbthreads.php/topics/1248818/1
 
Am I missing something here?

Amsoil's Signature Series, which starts with a TBN of 12.2, ends up around 3.0 on 10k mile OCIs?

Why would one then believe the SSO series can actually endure 1 year or 25k without the TBN dropping out completely?
 
I totally agree, used to run the Signature Series when children were in college, once a year changes etc maybe 10-15,000 mile OCI, did a lot of UOA back then and none of them ever came back with good enough results that said I could go to 25,000. Of course, Amsoil says 1 year or 25,000 unless you have UOA to back up going beyond a year. So, in effect they are saying it is good for one year or 25,000 whichever comes first. perhaps a ton of highway driving could get one to have 25,000 in one year and the oil still be okay. Persoanlly, I doubt it!
 
Originally Posted By: Doublehaul
Agree with the above two posts....was considering ss for my wife's car but the above comments and uoa have eliminated this oil from consideration


Why would a singular UOA cause you to not consider an oil? Completely different engine and application. I would be very hesitant to use an engine example with MAF issues and work being performed. Just to be fair - how would M1 perform here? We don't really know. But look at the first oil he used. Maybe not as good as M1, but gives you an idea.

Also - oil TBN depletion is not linear. It drops off rapidly, then levels of for an extended period of time. In this case (above) this certainly would NOT be a vehicle example for a 25K run, but a 15K would be doable.

I don't think the guys above are being all that fair, just jumping to conclusions. Thanks.

Originally Posted By: dkryan
Am I missing something here?

Amsoil's Signature Series, which starts with a TBN of 12.2, ends up around 3.0 on 10k mile OCIs?

Why would one then believe the SSO series can actually endure 1 year or 25k without the TBN dropping out completely?


I think you are missing the work that is being done to the engine, TBN depletion isn't linear and this is a case for 15K interval, not 25K.
 
It might be a good idea to use an OEM air intake and filter, as the Silicon figures are a bit high. The Lead figures indicate the main bearings seem to have an issue of some type and I would be inclined to cut the OCI to 5K and if that does not resolve the issue it might even be worth moving up a grade to an Xw40. If you do have an issue with the main bearings, thicker oil often helps.
Oddly enough the insolubles figure also seems a bit high, which is another reason to reduce the OCI.
 
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