6.6L Duramax Deisel
Good engine? What's your experience?
Forum Discussion
What Duramax are we talking about? The '01 thru "04.5 LB7 had injector problems. Otherwise, a decent engine. The '04.5 thru '05 LLY is said to have overheating problems. I have owned one since new and it does not overheat even towing big loads up mountains in the summer. In fact, with 178,000 miles on it, all working, towing, hauling something it has been the most reliable vehicle I've ever owned.
The '06 thru '07.5 LBZ is widely regarded as the best Duramax. This model gained HP and torque but did not gain emissions equipment like the following models. The Allison automatic with these engines went from a 5 speed to a 6 speed.
The '07.5 thru 2010 LMM was also a good engine. These had the regen for the DPF which caused poorer fuel mileage. Many trucks with this engine had trans. cooler lines that leaked but this has nothing to do with the Duramax engine.
I had a truck with this engine and except for the trans. cooler lines repaired under warranty it gave me zero problems the entire time I owned it.
The '11 LML engine gained lots of HP and torque. It also began the use of DEF which is probably a better emissions system than the previous one. There are no known widespread problems with this engine.
So, mostly, the Duramx has been a consistent smooth, reliable performer.
The '06 thru '07.5 LBZ is widely regarded as the best Duramax. This model gained HP and torque but did not gain emissions equipment like the following models. The Allison automatic with these engines went from a 5 speed to a 6 speed.
The '07.5 thru 2010 LMM was also a good engine. These had the regen for the DPF which caused poorer fuel mileage. Many trucks with this engine had trans. cooler lines that leaked but this has nothing to do with the Duramax engine.
I had a truck with this engine and except for the trans. cooler lines repaired under warranty it gave me zero problems the entire time I owned it.
The '11 LML engine gained lots of HP and torque. It also began the use of DEF which is probably a better emissions system than the previous one. There are no known widespread problems with this engine.
So, mostly, the Duramx has been a consistent smooth, reliable performer.
