2024 Chevy Tahoe LM2 Duramax 12,196 miles/252 hours on oil - 27,296 total miles/569 total hours - copper and tin in oil
This is the last UOA from my 2024 Chevy Tahoe 3.0L Duramax diesel engine. This engine had a faint lower end knock that I would listen to when I pulled it into the garage. At first I wrote it off to the fact that it's a diesel and diesels make knocking noises. When I got the last UOA back I about fell out of my chair. When I cut the oil filter I did fall out of my chair.
The UOA shows a rapid increase of copper and tin. The copper isn't coming from the oil cooler because it is all aluminum. The turbo has ball bearings, so no copper or tin there. After doing a lot of homework on where the copper and tin are coming from the only place in this engine that could be the source is main or big-end rod bearings.
I dumped the oil and cut the filter. Folks that is the second most metal I've ever seen in an oil filter. Not big chunks, but tons and tons of copper looking flakes and some slivered iron. The copper looking flakes are from the tri-metal bearings and the iron slivers are from the crank. There isn't any place else they could be coming from. The pictures of the metal in the filter element do it no justice. Digital cameras can't capture the sparkies like the human eye can. I'm going to keep the element in a zip-lock bag as a trophy. I never thought this would happen to me.
This engine has been making copper and tin from the moment it was first stated. The UOAs clearly show what's been happening.
Had I kept driving this motor, it certainly would have suffered a catastrophic failure. This was a manufacturer's defect and I wasn't willing to chance GM not honoring the warranty. I traded it for a 2025 Tahoe exactly equipped, except with a 6.2L gas motor.
Previous UOA here
I played with the exposure triangle to attempt to capture the sparkly flakes, but it's very hard to see them. I assure you they are there. You can see the piece of gasket material and some iron slivers.
Multiply the number of copper colored flakes you see here by 1000x.
This is the last UOA from my 2024 Chevy Tahoe 3.0L Duramax diesel engine. This engine had a faint lower end knock that I would listen to when I pulled it into the garage. At first I wrote it off to the fact that it's a diesel and diesels make knocking noises. When I got the last UOA back I about fell out of my chair. When I cut the oil filter I did fall out of my chair.
The UOA shows a rapid increase of copper and tin. The copper isn't coming from the oil cooler because it is all aluminum. The turbo has ball bearings, so no copper or tin there. After doing a lot of homework on where the copper and tin are coming from the only place in this engine that could be the source is main or big-end rod bearings.
I dumped the oil and cut the filter. Folks that is the second most metal I've ever seen in an oil filter. Not big chunks, but tons and tons of copper looking flakes and some slivered iron. The copper looking flakes are from the tri-metal bearings and the iron slivers are from the crank. There isn't any place else they could be coming from. The pictures of the metal in the filter element do it no justice. Digital cameras can't capture the sparkies like the human eye can. I'm going to keep the element in a zip-lock bag as a trophy. I never thought this would happen to me.
This engine has been making copper and tin from the moment it was first stated. The UOAs clearly show what's been happening.
Had I kept driving this motor, it certainly would have suffered a catastrophic failure. This was a manufacturer's defect and I wasn't willing to chance GM not honoring the warranty. I traded it for a 2025 Tahoe exactly equipped, except with a 6.2L gas motor.
Previous UOA here
| Sample Information | ||||||
| Sample Date | 5/4/2024 | 5/5/2024 | 9/22/2024 | 10/13/2024 | 01/06/2025 | 04/29/2025 |
| Machine Age miles | 3,000 | 3,050 | 13,690 | 15,125 | 20,650 | 27,296 |
| Oil Age miles | 3,000 | 50 | 10,640 | 25 | 5,550 | 12,196 |
| Makeup oil quarts total | 0 | 0 | 1 | 0 | 0.25 | 1 |
| Filter Age miles | 3,000 | 50 | 10,640 | 25 | 5,550 | 12,196 |
| Oil Changed | yes | no | no | yes | no | no |
| Filter Changed | yes | no | no | yes | no | no |
| Brand | OEM | HPL | HPL | HPL | HPL | HPL |
| Viscosity | 0w-20 Dexos D | HPL 0w-20 Dexos D | HPL 0w-20 Dexos D | HPL 5w-30 Dexos D | HPL 5w-30 Dexos D | HPL 5w-30 Dexos D |
| Wear Metals | (ppm/1k miles) | |||||
| Iron | 38(12.7) | 7(0) | 69(5.9) | 9(0) | 29(3.6) | 52(4.6) |
| Chromium | <1 | <1 | 1 | <1 | <1 | <1 |
| Nickel | <1 | <1 | <1 | 0 | 0 | 0 |
| Titanium | <1 | <1 | 0 | 0 | 0 | 0 |
| Silver | 6 | <1 | 5 | 1 | 2 | 1 |
| Aluminum | 4 | 3 | 11 | 7 | 12 | 16 |
| Lead | <1 | <1 | 0 | <1 | 0 | 0 |
| Copper | 10 | 2 | 93 | 12 | 154 | 289 |
| Tin | 2 | <1 | 4 | <1 | 7 | 21 |
| Vanandium | <1 | <1 | 0 | 0 | 0 | 0 |
| Cadmium | <1 | <1 | 0 | <1 | 0 | 0 |
| Additives | ||||||
| Boron | 40 | 106 | 70 | 89 | 74 | 61 |
| Barium | 3 | 2 | 1 | 0 | 0 | 4 |
| Molybdenum | 27 | 71 | 74 | 63 | 80 | 71 |
| Manganese | 2 | <1 | 2 | <1 | 1 | <1 |
| Magnesium | 15 | 876 | 1065 | 847 | 1018 | 964 |
| Calcium | 1781 | 1167 | 1387 | 968 | 1152 | 1017 |
| Phosphorus | 879 | 798 | 769 | 664 | 696 | 605 |
| Zinc | 927 | 821 | 907 | 762 | 832 | 735 |
| Contaminants | (ppm/1k miles) | |||||
| Silicon | 104(35) | 23(0) | 44(2) | 14 | 18(0.7) | 17 |
| Sodium | 2 | 0 | 2 | 2 | 2 | 1 |
| Potassium | 5 | 3 | 2 | 0 | 2 | 2 |
| Fuel % | <1 | <1.0 | <1.0 | <1.0 | <1.0 | <1.0 |
| Glycol | NEG | NEG | NEG | NEG | NEG | NEG |
| Soot% | 0.2 | 0.1 | 0.6 | 0.1 | 0.4 | 0.6 |
| Fluid Condition | ||||||
| TBN | 7.9 | 12.54 | 11.21 | 13.15 | 14.03 | 9.93 |
| Viscosity | 8.2 | 8.9 | 9.1 | 9.9 | 10.1 | 10.3 |
| Oxidation | 11.2 | 0(30) | 5.7(35.7) | 0(32.1) | 2.1(34.2) | 3.9(38.1) |
I played with the exposure triangle to attempt to capture the sparkly flakes, but it's very hard to see them. I assure you they are there. You can see the piece of gasket material and some iron slivers.
Multiply the number of copper colored flakes you see here by 1000x.
Last edited by a moderator:
