Some 2024-2026 Silverado 2500HD/3500HD and Sierra 2500HD/3500HD trucks equipped with the 6.6L Duramax diesel engine (RPO L5P) may have an engine oil leak. In many cases, the oil leak may be caused by damaged engine oil cooler seals (Fig. 3) and not the oil cooler.
Fig. 3
Inspect the oil cooler area for oil seepage. (Fig. 4) If a leak is found, remove the oil cooler and check the seals.
Fig. 4
If the engine oil cooler seal is visually damaged or has debris on it that may cause a leak, replace the oil cooler seal. (Fig. 5)
Fig. 5
If the engine oil cooler seals do not have any damage or debris, replace the oil cooler. Refer to Engine Oil Cooler Replacement in the appropriate Service Information.
Check Bulletin #25-NA-150 for more details, including part numbers.
– Thanks to Larry Yaw
