Turbocharger

To help meet more demanding emissions regulations, GM introduced the LML Duramax diesel engine for the 2011 model year. This generation of the turbo-diesel saw horsepower increase to 397 and torque bumped up to a respectable 765 pounds-feet.

But even with its improved performance specs and the ability to support up to 550 rear wheel horsepower, the LML’s Garrett GT3788VA turbocharger was the smallest of any of the variable geometry turbos previously offered in the Duramax. The turbo had a 60.6-mm inducer on its compressor wheel and exhaust housing vanes measuring a little over 11 mm thick.

While these specifications helped with throttle response and turbine braking, they restricted flow within the turbocharger, allowing temperature and exhaust drive pressure to increase dramatically and leading to premature wear on engine parts.

Restore your 6.6-liter GM Duramax’s boost with a new turbocharger, an LML turbo rebuild kit, or gaskets from ProSource Diesel.