Bought this 97 GMC Sierra used back in March 2011 with 76,000 miles on it. It is in like new condition and runs well and I plan on keeping it for the rest of my life. I only drive it when I need a truck and only put about 125 miles a month on it but I always get it up to full temp before garaging it till next time.
Blackstone is the lab and they warned me about coolant contamination the has been in all 3 oil samples. When I bought the truck the intake manifold was leaking badly and had the repair done. Potassium keeps dropping it seems and my question is do you think the coolant seen is still left over from the repair? Maybe since I don't drive this truck much I have not done enough oil changes and miles to fully flush the coolant. Of maybe the repair was not done properly and still leaking coolant into the oil?
The coolant overflow tank is very stable and I only have to top it off once a year with a few oz. to keep it right on the full hot line. I was thinking this amount was from evaporation rather then internal leaking in the manifold?
What do you guys think? Also look at copper, silicon, lead all still dropping and Iron leveled out. And why is boron up? TBN is 5.1 even after 17 months in use and insoluble are low at 0.2 so this is a clean engine I think! Here is some details on the truck and sample:
*84,271 miles on engine/truck
*2,086 miles on oil and 17 months.
*Oil in use from 82,185 to 84,271 miles and from 4/11/2012 to 9/11/2014(17 months)
*Castrol GTX 5w30
*Napa Gold oil filter.
*Napa Gold air filter has 2,000 miles on it now.
*1st UOA was a auto RX cleaning cycle and the 2nd UOA was the rinse cycle and the 3nd UOA is this sample with just 2,086 miles and 17 months in service.
1st number is 1st UOA with the 3rd column being this sample is this UOA. Both UOA's have 3,000 miles on them:
ALUMINUM 3/4/3
CHROMIUM 1/1/1
IRON 22/10/8
COPPER 104/51/27
LEAD 24/13/8
TIN 0/5/4
MOLYBDENUM 2/3/2
NICKEL 2/1/0
MANGANESE 1/1/0
SILVER 0/0/0
TITANIUM 1/0/0
POTASSIUM 44/34/24
BORON 8/7/35
SILICON 79/61/38
SODIUM 274/342/117
CALCIUM 1515/1784/1873
MAGNESIUM 10/9/9
PHOSPHORUS 640/703/653
ZINC 686/843/746
BARIUM 0/0/0
SUS Viscosity @ 210 F 56.3/56.1/55.8
cSt viscosity @ 100 C 9.16/9.10/9.02
Flashpoint 415 F 415/420/435
Fuel 0.5/0.5
Antifreeze POS/POS/POS
Water 0/0/0
Insolubles 0.3/0.3/0.2
TBN 4.2/2.9/5.1
Any advice or comments is appreciated! Here she is:
Blackstone is the lab and they warned me about coolant contamination the has been in all 3 oil samples. When I bought the truck the intake manifold was leaking badly and had the repair done. Potassium keeps dropping it seems and my question is do you think the coolant seen is still left over from the repair? Maybe since I don't drive this truck much I have not done enough oil changes and miles to fully flush the coolant. Of maybe the repair was not done properly and still leaking coolant into the oil?
The coolant overflow tank is very stable and I only have to top it off once a year with a few oz. to keep it right on the full hot line. I was thinking this amount was from evaporation rather then internal leaking in the manifold?
What do you guys think? Also look at copper, silicon, lead all still dropping and Iron leveled out. And why is boron up? TBN is 5.1 even after 17 months in use and insoluble are low at 0.2 so this is a clean engine I think! Here is some details on the truck and sample:
*84,271 miles on engine/truck
*2,086 miles on oil and 17 months.
*Oil in use from 82,185 to 84,271 miles and from 4/11/2012 to 9/11/2014(17 months)
*Castrol GTX 5w30
*Napa Gold oil filter.
*Napa Gold air filter has 2,000 miles on it now.
*1st UOA was a auto RX cleaning cycle and the 2nd UOA was the rinse cycle and the 3nd UOA is this sample with just 2,086 miles and 17 months in service.
1st number is 1st UOA with the 3rd column being this sample is this UOA. Both UOA's have 3,000 miles on them:
ALUMINUM 3/4/3
CHROMIUM 1/1/1
IRON 22/10/8
COPPER 104/51/27
LEAD 24/13/8
TIN 0/5/4
MOLYBDENUM 2/3/2
NICKEL 2/1/0
MANGANESE 1/1/0
SILVER 0/0/0
TITANIUM 1/0/0
POTASSIUM 44/34/24
BORON 8/7/35
SILICON 79/61/38
SODIUM 274/342/117
CALCIUM 1515/1784/1873
MAGNESIUM 10/9/9
PHOSPHORUS 640/703/653
ZINC 686/843/746
BARIUM 0/0/0
SUS Viscosity @ 210 F 56.3/56.1/55.8
cSt viscosity @ 100 C 9.16/9.10/9.02
Flashpoint 415 F 415/420/435
Fuel 0.5/0.5
Antifreeze POS/POS/POS
Water 0/0/0
Insolubles 0.3/0.3/0.2
TBN 4.2/2.9/5.1
Any advice or comments is appreciated! Here she is:
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