Where are the engine drain plugs on duramax diesel 6.6L?

The location of the engine oil drain plug on a Duramax 6.6L diesel engine depends slightly on the year and specific model of the vehicle it's in, but it's generally found in the bottom of the oil pan, towards the front of the engine.

To be precise, you'll need to consult a repair manual specific to your year and model. Looking at diagrams in a repair manual will show the exact location and also give you crucial information about the correct type of drain plug and the proper torque specification when reinstalling it.

Do not attempt this repair without the proper tools and knowledge. Incorrectly tightening the drain plug can cause damage. If you're not comfortable with this repair, take your vehicle to a qualified mechanic.