2011-2015 GM 6.6L LML DURAMAX
The LML debuted in 2011 and continued through 2016. To easily identify the 11-16 LML motor the eighth digit in the vin number will be an “8”. The LML would end up being the last generation for the well-known 6.6L motor along with the most changes that we have seen to date. The LML is the first generation to use Diesel Exhaust Fluid (DEF), went from a standard Bosch injector to a new even higher pressure piezo style injector, which lead to changing the injection pump from a CP3 to a CP4, plus many other motor and emission changes. The LML came out of the box with great efficient power and it towed well while keeping temperatures in check. The Allison transmission backing this motor up was the strongest yet. It came with a stronger torque converter and Allison equipped the valve body with their version of a shift kit which helped line pressure.
A few common issues arose with the big changes. The exhaust and DPF filter seems to work a bit more efficiently with the newly introduced DEF system, but it still has restriction and clogging issues. The high pressure CP4 injection pump does well until they fail, and when they do fail they take more out than just the pump. The LML has the same desires the earlier models needed for fuel filtration and pressure, simply adding an aftermarket lift pump/filtration system will increase injector performance and longevity.