M1 10-30,'01 8.1L (496) Chevy Silverado, 6,600 miles, High lead help!?!

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EQUIPMENT MAKE: GM
EQUIPMENT MODEL: 8.1L 496 CI V-8
FUEL TYPE: Gasoline (Unleaded)
OIL USE INTERVAL: 6,692 Miles
OIL TYPE & GRADE: Mobil 1 10W/30 (Gas)
MAKE-UP OIL ADDED: 1 qt
REPORT DATE: 10/16/03
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COMMENTS:

RAVEN: Since you're not using any additives & the engine hasn't been opened since it was new, the
high lead we found must be coming from your bearings. Is the engine running okay? We would not
normally talk about 8 ppm sodium, but perhaps it shows a slight coolant seep. The lead is coming from
your bearings -- we just can't say for sure why. The TBN read 5.3, strong, but we don't suggest
running the oil any longer than this until we know why lead is high. Check back @ 3000 miles
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MI/HR ON OIL       6,692 7/7/03 to 10/2/03)
MI/HR ON UNIT     45,904 MI/1229HR
SAMPLE DATE       9/2/03

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               this sample      fresh oil  
TBN            5.3              10-12.5
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ALUMINUM       4                 0
CHROMIUM       1                 0
IRON          26                 1
COPPER         5                 0
LEAD          51                 0
TIN            4                 0
MOLYBDENUM    93                69
NICKEL         1                 0
MANGANESE      0                 0
SILVER         0                 0
TITANIUM       0                 0
POTASSIUM      2                 0
BORON        159               190
SILICON        8                 3
SODIUM         8                 9
CALCIUM     3609              2976
MAGNESIUM     31                16
PHOSPHORUS   920               749
ZINC        1155               827
BARIUM         0                 0
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sus [email protected]
210˚f         65.4              58.3
flash point  365f              390f
fuel%          0.5            No Data
antifreze%     0              No Data
water%         0.0            No Data
insoluables%   0.3            No Data

fresh oil reference values taken from http://theoildrop.server101.com/ubb/ultimatebb.php?ubb=get_topic;f=11;t=000095 a VOA of all the M1's sent to the same lab as my sample (Blackstone Labs) TBN is a guesstimate from other M1 VOA's of different weights I could only find one 1 M1 10-30 voa and is was kinda old (feb of 03) not sure if has changed since then? http://theoildrop.server101.com/ubb/ultimatebb.php?ubb=get_topic;f=11;t=000068#000000 realy I guess what it started with not important as long as there is some left when I chenge the oil oil capacity is 7QT +1 makeup so we are talking about 2gallons of oil total. that is a lot of oil to dilute that wear metal into but then again it is a large engine with a lot of metal to wear not sure how to look at that, unfortunately there are not other UOA's on this Engine that I can find, its closest sibling is the 454 (7.4L) but it is a complete redesign not sure if the bearings are similar I did find one 454 report http://theoildrop.server101.com/cgi/ultimatebb.cgi?ubb=get_topic;f=3;t=000164 it's lead was low at 11PPM and it even had an internal coolant leak and it has less bearing wear than mine I use ACdelco “duraguard gold” filters witch are suppose to be excellent in both flow and filtration thanks to synthetic media, but unfortunately no longer made in my size. My stock of them is running low. this was only suppose to be a baseline for experiments with other filters. air filter was changed in the middle of the OCI insolubles and silicon look ok so that is not a source of the problem Like a lot of other Chevy “vortec” engines this one has cold start knock and has since 250 miles (a few mornings after I bought it) hut that was suppose to be a piston and piston bore problem the piston is aluminum the block head and rings are steel/, iron and aluminum in the report are acceptable, I have been on a lot of chevy/chevy truck forums this is the first I have heard of bearing problems the tuck is used mainly for a commuter I live 35miles from work almost all of it freeway and highway, it is 15 miles into town so no short trips here, it sees occasionally sees heavy towing, and did once on this OCI, I hauled a Toyota truck on a tailer to east Tennessee and back again almost all highway, this is suppose to be a heavy duty truck should have taken that trip with no complaints Never though I would have bearing problems @ less than 50K, truck is not even payed for yet but out of warranty [Mad] I am a mechanic by trade but not automotive, this is the first time I have dealt with oil analysis and I an not sure what to do about the bearing wear? Is this bearing going to fail immediately? Can you even tell that from a reort? Should I drop the pan and have a look or watch it for the next 2,000 miles and take another sample? [ October 16, 2003, 06:20 PM: Message edited by: RavenTai ]
 

RavenTai

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wanted to add oil filter is over sized, the original was very small I use the 454 filter (upf1218) with is identical except for height that should only be a positive thing as far as I know I did its first oil change a 500 miles with castrol gtx 10-30 and then at 1200 with M1 10-30 (M1 from then on) and again every 3K until 22,000 when I started using the oil change light witch is suppose to come on between 3 and 10k depending on driving conditions and temperature for me it comes between 5 and 7k truck was manufactured May of 01 and purchased October of 01, the long sit and appearance of the cold start knock so early was the reason for the early first oil change [ October 16, 2003, 06:13 PM: Message edited by: RavenTai ]
 

Al

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Well-the oil held up well. I certainly would be concerned with the lead (not so much with iron). The oil did thicken more than Mobil 1 usually thickens-which can be a sign of antifreeze. I would defenitely pay Terry Dyson the $10 or so to interpret your results and provide some guidance. Terry is a top shelf guy and it will be money well spent. [Smile] And he is a Site Sponsor [Smile] [ October 16, 2003, 06:22 PM: Message edited by: Al ]
 

RavenTai

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the water (would have boiled off anyway) and antifreeze come up 0 in the report and up until I changed it out about a month ago the level never dropped I think i am going to go mark the surge tanks level with a sharpie and keep an eye on it this truck uses that newish dexcool will the analysis still read it? It may be a good idea to get somebody to take a look at it
 

wtd

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Raven Tai, Did you use any kind of fuel injector treatment anytime during this oil run? On my first oil analysis on my 98 5.7L vortec using 5W-30 Mobil 1 and going 5,000 miles, I had 55ppm of lead. During this oil run, I had used Chevron Techron. My next analysis with 3,000 miles on the oil, showed 18ppm of lead without using any Techron. My next one using techron with 3,000 miles on oil, went up to 43ppm of lead. I would do another couple of analysis to see what your trend looks like. Wayne
 
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The water would have mostly burned off, but if you had the internal intake gasket leak, you'd probably still see condensation and goo on the underside of your oil fill cap and at your PCV valve. Potassium and sodium seem to be acceptable in your sample. [I dont know] I'd try using another brand of oil and resample at 3,000 miles and keep a constant eye on your coolent level and also oil fill cap and PCV valve. Does the truck run good? I ask because 3 of our GM vehicles have had the intake gasket failure. All of them had only slight traces of coolent in the oil, but the big thing was that for some reason, the gasket also failed between some of the intake runners and produced noticeable vacuum leaks that created major part throttle hesitation. Once floored and in open loop, they ran fine though.
 

RavenTai

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WTD: I did not use any during the period tested but I use almost exclusively Chevron 97 octane gas with Techron last weekend I put in 2 bottles of the cleaner so the next sample will have it Drew99: your GM's may have had dexcool (the red stuff), did the analysis catch the coolant contamination? the water would have burned off but the glycol (or whatever it is now) would be left behind the truck runs strong but I have suspected an intake leak on this truck for a wile to be the source of my oil usage, there is a TBS to replace and re-torque the intake bolts for oil usage fortunately the 8.1 has no coolant passages in the intake, it has a cast iron crossover pipe in front of the block for the outlet instead of using the intake, only place it can get into the crankcase is head gasket leak or crack in the block or head I have seen the milk on the bottom of an oil cap when water gets in the crankcase on other cars like you describe, none here, it has no pcv valve either it has some kind of baffle and a hole arrangement on the bottom of the intake drawing excess gases from the valley area [ October 16, 2003, 08:58 PM: Message edited by: RavenTai ]
 
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We never had oil anaylsis done on those vehicles. I did not know the 8.1 had a dry intake manidold design. That 's good to hear, considering all of GM's problems with intake gaskets.
 

RavenTai

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quote:
Originally posted by Chris142: Where do you get 97 octain gas? [Confused]
errr oops [Duh!] the good stuff, 93?
 
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I had a 97 F150 with the notorious 4.2L that seized due to antifreeze. Never saw any in the oil, nothing on the cap, never saw the coolant level go down either. Well it did once the motor started knocking, but it was at the end. I would suspect something in the coolant system. Have it pressure tested. Ford dealership put dye into the coolant, pressure tested itor ran it, then drain the oil to look for the dye. Maybe try a new gas station. [Confused]
 

RavenTai

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OK I found out Dexcool is still ethylene glycol it just has a different set of inhibitors from the normal green stuff so it would show in the analysis if it were present in the oil in a high enough concentration the sodium Blackstone observed is very similar to the VOA of M1 so it came in with the fresh oil, that only leaves the thickened oil as in indicator of a coolant leak but I understand many things including heat can thicken oil? I marked a cold and hot mark on my surge tank, this is a closed system (no low pressure "puke tank") so any drop has to be a leak, I opened the surge tank and it still had pressure after almost 20 hours since the last drive if the head gasket is leaking it is very very slow there was no oil sheen on top of the coolant or any other evidence it looked clean when I get some time next week I am going to do a compression test see if there is a low cylinder somewhere dickwells, after your post I searched and did not find a direct reference for the automotive 8.1l but the bearings in a 8.1l modified with a turbocharger in a generator has them listed: "Main Bearings Style...........Aluminum/Lead Silicon Alloy" no coper listed not sure if they replace the bearings the motor comes with from GM? the al and SI levels were low in the analysis but the bearing alloy may be a lot more lead than the other two elements http://www.gillettegenerators.com/download/SINGLE-MODEL-SPEC-4PG-SHEETS/SPC4-SP1250-20030309.pdf so it looks to me either there is no coolant leak or it is extremely small, would such a small amount of glycol in the oil (less than Blackstone can read) cause bearing wear like that? Or the lead came in with the gas in some way? Either as techron as WTD suggests or some other source Or the bearing is just junk out of round/damaged/burr Or just a fluke? If the next report comes back with lead again would it be advisable to go to a thicker oil to increase bearing film strength? I had been thinking of moving to Mobil Delvac 5-40, It has a better cold flow start (5w) so it will get to the bearign quicker and better film strength at temperature, then the 10-30 I am curently using, both should be better for the bearign as far as I can see, I live in the south so there are no extreme cold starts here no need for a 0w GM recommends 5-30 in their vehicles with 10-30 being acceptable but not recommended, I think GM is more worried about CAFE fuel economy averages than bearing wear (99% will make it past the 36k warranty no mater what oil you use, what do they care) [ October 18, 2003, 08:18 AM: Message edited by: RavenTai ]
 
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Assuming that your coolant level has not changed there appears to be no other signs of coolant usage to account for high lead wear. Personally, as there is no trend on this engine we just don't know if this is normal, severely abnormal etc. I have seen my lead numbers spike like this for no apparent reason and then drop down etc. To assume that your bearings are going to fail soon is wild speculation. they could go another 200,000 miles, no one knows. So, if my engine I would not lose sleep over it and sample around 3000 on the next batch of oil and see what it looks like. Never jump to conclusions on one sample IMO!
 
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I'd assume the metallurgy of this 8.1L engine is similar to other Vortex V-8's. Normal lead wear would be more along the lines of maybe 15-20 ppm after 7000 miles. So this is a bit high, but nothing to panic about. It could well be fuel related as some have mentioned. I'd do another run of Mobil 1, 10w-30 and test it again in 3000 miles. I'd also switch to another brand of fuel and not use any fuel additives. I don't think you need to run a 5w-40 in this motor, but you could try some Delvac 1 just to rule that out. All the other wear metals looks normal, so this could just be a fluke thing. I see no evidence of coolant or dirt contamination. The total solids level is fine and silicon is low. Tooslick
 
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