This category is dedicated to the GM Duramax LLY 6.6L diesel engine in Silverado and Sierra 2500/3500 trucks. Our Duramax LLY content includes articles such as the best LLY performance upgrades and the most common engine problems. Duramax diesels are a big focus for the ChevyTrucks team, so check back for more unique, insightful LLY guides.
While the Duramax LLY was an unquestionable improvement over the LB7, it still had a few kinks. One of the main complaints among owners is overheating, which is caused by both a restrictive intake horn and also downpipe. Upgrading the downpipe is one of the best options for preventing overheating and is also one of…
The factory intake on the Duramax LLY is really restrictive. As such, a cold air intake upgrade will add up to 15 horsepower and 25 torque while also providing benefits like lower EGTs, faster turbo spool and throttle response, and even 1-2mpg increases in fuel economy. The performance benefits and overall efficiency improvements make a…
With the capability of the stock turbocharger, the LLY Duramax left tons of power on the table. These engines are capable of pushing beyond 500rwhp with just a few bolt-on mods, and an upgraded transmission. In this guide we are going to cover the LLY’s power limits and discuss the 7 best performance upgrades to…
In order to meet stricter emissions regulations, the LLY replaced the LB7 engine and was the first Duramax to use EGR emissions technology. Unfortunately, the new EGR system was problematic leading to common valve failure. Aside from this addition the new engine received a variable vane turbo and eventually got some block and internal upgrades…
