WATCH: GM Duramax Diesel Engine Teardown Shows What Can Kill Trusty Oil Burners

The engine was then turned over on the stand to remove the oil pan. The parts underneath appeared in good condition, including the balance shaft cassette, saps, bearings, and crankshaft. However, the walls in cylinder four had sizable damage.

With the engine torn down, Eric concluded the mill ran with bad injectors, which might’ve led to failures such as detonation that cracked the pistons. Several factors could damage the injectors, including fuel contamination. Considering the history is unknown, we couldn’t be so sure about this particular engine.

New Colorado and Canyon buyers won’t need to worry about dealing with diesel engines. They won’t even miss its torquey power delivery, too, as the current turbo 2.7-liter inline-four gasoline replacement for the 2023 model year is claimed to be “so good” that a diesel option is no longer required.