GM has released official exterior images of the upcoming 2017 Chevy Silverado HD and 2017 GMC Sierra HD trucks. However, most other details and specifications remain unknown. GM has recently published an order guide for its 2017 HD truck lineup, and the engine code for the 2017 6.6L Duramax turbo-diesel engine is L5P. It replaces the LML version of the 6.6L Duramax engine.
TFLtruck received these images from under the hood of a 2017 GMC Sierra HD Denali from an anonymous source. While the low resolution of these images hides some components, several details come to light. The air intake is still on the passenger side of the engine bay, but it has a grommet that points up to meet with the hood. While there are no images of the underside of the hood itself, GM announced that the center hood scoop of the 2017 HD trucks is functional. It is possible that there is ducting in the hood that delivers air directly into the intake.
Disclaimer: TFLtruck has not confirmed whether these images represent the final production appearance of the 2017 HD Duramax engine bay.
The DEF (Diesel Exhaust Fluid) filler cap is still on the passenger side of the engine bay. You still get the dual batteries, but many components, hoses, and wiring have been moved around. Refer to the image below of the LML version of the Duramax.
The new diesel specifications have not been announced yet, but there are rumors that the latest Duramax V8 will produce around 445 horsepower and 850 lb-ft of torque.
The other important news about the 2017 HD trucks from Chevrolet and GMC is the base engine. The previous 6.0L Vortec gasoline V8 continues duty for the 2017 model year with the same power output as before: 360 horsepower @ 5,400 rpm and 380 lb-ft of torque @ 4,200 rpm.
Here is a TFLtruck spy video of a 2017 GMC Sierra HD prototype testing at high elevation of the Rocky Mountains.