What is the most reliable year Duramax?

Chevy and Isuzu’s Duramax engine is one of the most reliable and effective engines ever produced for a truck, and depending on what you want them for can be worth quite a high price tag.

The best years for the Duramax are 2006 and 2007. These engines are both highly reliable and capable of a fantastic output. The only commonly stated problem with the 2006-2007 Duramax is that the pistons tend to crack when the engine runs higher than 600 horsepower.

But what sets these models apart from the other models of the Duramax engine, and are there other good alternatives within the product line? 

Why The LBZ 2006-2007 Is The Best Duramax Engine

Before we say anything else, it’s important to make it clear that there aren’t really any bad years for the Duramax engine.

All of the Duramax engines since 2001 have been great machines that are both reliable and powerful, the two most important qualities in a truck engine. 

That said, several things make the 2006-2007 Duramax especially desirable. 

First and foremost, it avoids the injector problems suffered by the 2001 model and the overheating problems with the 2004 model. 

Each of these problems was expensive for consumers to resolve. 

These problems impact more than just the engine’s price tag, it also negatively impacts its reliability. 

The 2006-2007 Duramax engine also lacks the emission controls of later models, which have their trade-offs. 

While this does decrease the number of potential failure points on the engine itself, it does make the vehicle a bit worse for the environment. 

If your primary concern is engine reliability, then this is a price worth paying.

The other big problem with the LBZ is that if its output is ever higher than 600 horsepower, the pistons have a tendency to crack, which is bad. 

Or it would be if 600 horsepower wasn’t far beyond the LBZ’s usual range of function. 

The only way to get its output that high is to spend about $20,000 modding the engine. 

In other words, few people will experience this problem.

The biggest downside (for non-drag racers) of the LMZ is easily its price point. 

Since it’s perceived as the best engine of its kind, it sells at a price tag that reflects that.

Many people see its price as higher than the value it provides. 

The 2006-2007 Duramax engine is getting fairly old; however, it is still significantly cheaper than buying a brand new vehicle/engine.

But despite its age, the LMZ is still worth the money.

These engines are known to have very few problems, and if the last fifteen years are any indication, they’ll probably last another couple of decades.

Other Duramax Engines

Of course, as earlier mentioned all Duramax engines are high-quality engines.

Let’s take a look at the highlights.

LB7 2001-2003

This engine is getting to be pretty old now, but it is still powerful and reliable. 

Because of its age, it’s probably the cheapest Duramax engine around. 

The lower price may be a result of its infamous injector problems.

These issues can cost thousands of dollars in repairs.

That said, even with the cost of an injector replacement added in (which you might not have to since the previous owner might have already had it done sometime in the last twenty years, a good condition LB7 is unlikely to cost more than $19,000. 

This is a high price but still about the same as a good condition 2004 LLY, which might end up having more problems due to its overheating issues.

For these reasons, the LB7 is the best budget Duramax, although the LLY is also fairly reliable and a valid choice on that front.

LBB 2008-2010

The LBB is almost identical to the LBZ before it, with the only major difference being the addition of emissions controls for the first time to the engine. 

Because of this, the LBB is a more environmentally friendly alternative to the LBZ. 

The condition of the LBB could also make it cheaper than the LBZ. 

The price range on the LBB is pretty wide, as the model is only about twelve years old and can still command a respectable price.

All around, the 2008-2010 LBB is a great model that gets a little less attention than its older brother because of its slight dip in reliability for emissions controls. 

This is a standout choice among the Duramax lineup.

L5P 2017-Present

This is the most recent version of the Duramax engine, and it’s generally quite well regarded. 

It has a great output and certainly seems to be a great engine. 

However, it is brand new, which means that we have very little data to go off of when evaluating the engine’s reliability.

Some previously unnoticed engineering problem may unearth themselves in the coming years that proves this engine to be inferior to its predecessors; however, as of right now there’s no reason to believe that it isn’t the best of its class. 

In a couple of years, a new version of this article might even have the L5P where the LBZ sits now.

For now, we’ll withhold casting too much judgment on this particular model.

LGH 2011-2016

This is a weird little engine that was created specifically for the Chevy Express. 

Discontinued in 2017, it had incredibly similar specs to the LML from the same period. 

The only major difference was its decreased power rating for a smaller vehicle. 

Is it a good engine? Not good enough that you’d ever want to transplant it in a new vehicle.

But it’s fine for a 2011-2016 Chevy Express.

It doesn’t seem to have any major problems that aren’t also seen on the LML, which means it’s probably about the same level of reliability.

Of course, the Chevy Express isn’t a truck, it’s a van. 

You wouldn’t buy it for the same reasons you’d buy any of the other vehicles that use Duramax engines, which means that judging the LGH by the same standards we judge other Duramax engines would be a little unfair.

Overall, the LGH seems to be a solid engine for a van.