Diesel Tuner's Blog

The 3.0L Duramax is a wildly capable inline 6-cylinder diesel engine designed for full-size half-ton pickup trucks and SUVs. Due to its amazing power-to-weight ratio and towing performance, GM has chosen to offer this engine in everything from Chevy Silverado 1500 to the Chevy Suburban and even the Cadillac Escalade. Clearly, GM is confident in its new design. 

The new 3.0L Duramax shares very little in common with its predecessor the 4-cylinder 2.8L Duramax. It's been completely redesigned from the ground up and features many improvements such as a forged crankshaft, forged steel connecting rods, and a much stronger block design. The result is an engine that can produce 277 hp and 460 ft-lbs. of torque. Which is comparable torque to that of the more expensive 6.2L gas engine that is offered in most of the same vehicles that the 3.0L is offered in. 

Stock Duramax Turbo Upgrades!

Duramax owners are generally proud of how their stock turbos perform.  They spool quickly, run hard and are capable of over 500 RWHP (once you tune it and make a few supporting modifications to handle the power).  However, after driving your truck around 520 RWHP for a while, the addiction will creep in and you may find yourself shopping for more power.  We all do it!  For some, it may not even be about more power, it may be about EGT control under load, or it may just be the factory turbo had an issue and needs to be replaced.  If you are anything like me, you will not want to replace it with the factory components if there is an upgraded, after market, charger available. 

So many truck come into our shop with high EGT's, turbo lag, excessive smoke output, and bad fuel mileage which are all symptoms of a boost leak. It is so common to devlop boost leak that we now require all trucks to have a boost test done prior to strapping them down on the dyno. What's funny, is that no one shows up knowing they had a boost leak. The reality is that even if you can hit peak boost, you may have a leak, especially if you have a variable vane turbo. Variable vane turbos will change vane position and other operations to try and achieve a desired boost number which may cover up a leak in the charged air system. 

3 SIMPLE THINGS YOU CAN DO TO HELP KEEP YOUR LML DURAMAX RELIABLE:

Your truck is generally one of the largest investments you will make, so keeping it on the road is priority number 1!

The LML Duramax is one of the best trucks GM has ever produced. With 397 Horse Power and 796 ft/lbs of torque from the factory, the truck has the power plant necessary to do just about any job you can throw at it. However, despite the massive improvements the LML has brought to the table, there are some all too common pitfalls that can make this beast a burden. 

Here are some other places you can read more about the LML Duramax:

• LML Duramax SPADE
• Truck Trend Review of LML Duramax

• The LLY Duramax  is a great truck from the factory for there are 3 modifications every owner should make! The LLY was manufactured 2004.5 and 2005. There are a few 2006 models that are labeled as an LLY, however they have all of the LBZ upgrades from the factory, so for performance applications consider those an LBZ. An LLY was the first Duramax with the injectors outside of the heads, a variable vane turbo and a 50 state EGR.