Chevy produced a whole line of great diesel engines in their Duramax family. They listened to the drivers and always worked on new and improved engines. In 2006. came an LBZ Duramax, now known as the most reliable Duramax until then. If you are buying a used Duramax engine, you should know how long an LBZ Duramax lasts. That way you can choose the right engine for you.
If handled and maintained properly, the LBZ can easily last over 300,000 miles without major repairs. If you fell in love with the truck and the engine, you can keep it alive for much longer. There is a wide choice of all-important aftermarket parts for this engine that will keep it running even after 500,000 miles.
If you are looking for a reliable diesel engine, you don’t need to look further than the 2006-2007 LBZ generation of engines. The older LLY had issues with overheating. Newer generations had problems with new emission standards that included a diesel particulate filter, so the LBZ is the golden standard.
Factors That Affect the Longevity of an LBZ Duramax
When we put aside the overall quality of the engine, its build, and its features, other factors impact its longevity. These factors apply to all engines. No matter the quality of the engine, the life expectancy will be longer if it is well-maintained. Also, factors like the way the truck is driven, for what purpose, and what type of fuel is used are important.
Regular Maintenance
Regular maintenance will help in keeping the life expectancy at the maximum. That includes regular changing of all the filters. You should pay attention to these components:
- The fuel filter. That is the main component that keeps the fuel system clean from metal debris and water. If there is too much water mixed with fuel, it will harm the performance and overall work. It should be changed every 10,000 miles or even earlier
- The oil filter. It is keeping the oil clean from all the impurities and metal debris coming from the metal parts. The oil filter keeps most of them away from the oil. If the oil becomes dirty with those shavings it will make a lot of problems for all the components. Like the fuel filter, you should change it every 10,000 miles, or sooner if you have the chance
- The transmission filter. Its role is to keep the transmission fluid clean. A clean transmission fluid will keep all the parts well-lubricated and cool. Filter change comes every 50,000 miles
- The air filter. This filter is responsible for keeping all the dirt, dust, insects, and junk from entering your engine. That results in maintaining the best air-to-fuel ratio which improves overall performance.
With filters come oils and fluids. Pay attention to these:
- The engine oil. Use high-quality synthetic oil with correct viscosity. For temperatures above 0 °F, it is recommended to use 15W40 oils. Look for high-quality oils with additives that will extend the engines life
- The transmission fluid. Depending on the type of automatic transmission fluid, you will need to change it every 50,000 or 150,000 miles.
Conditions and Habits While Driving
Extreme temperatures are one of the factors that will impact the work life of an engine. Extreme cold temperatures can result in problems with glow plugs and starting the engine. Constant hot temperatures are also not good for the engine especially if the truck is left in the direct sun for a long time.
Temperatures are not the only factor. The others are the style of driving and the purpose of the truck. If the truck is used mainly in the city, where there is a lot of stop-and-go driving, that will shorten engine life. Also, towing extra heavy loads in high temperatures will result in the shortest life expectancy.
Quality and Usage of Fuel
There are a lot of types of diesel in the market. They come with different quality, different or no additives, and they impact the engine. It is recommended to use high-quality diesel fuel with additives for extra lubrication. You can even use biodiesel without any problems.
FACT: There is a myth that the use of biodiesel can result in fuel pump failure or other fuel system issues. Time showed that this fuel is completely safe to use.
Modifications and Upgrades
Different upgrades can help the LBZ to work longer. On the list of priorities are the aftermarket fuel pump, and better fuel transmission lines. These issues are the most common on the LBZ. Also, upgrading pistons and other major parts of the engine can extend its life.
You can expect that the bad fuel injectors will come at you at some point. When you do the fuel injector replacement, try to find better ones than the originals.
If you decide to tune the engine, do not go overboard. Keep everything within safe limits, and replace all the parts with improved ones.
What Is The Mileage Expectation of an LBZ Duramax
If you maintain the engine properly you can expect it to run at least 300k miles. Also, the truck’s purpose will dictate how long the truck will last. Towing trucks or trucks used in heavy city traffic will have more frequent issues and will demand better maintenance.
There are cases where these engines have passed even 500k miles. Most of the major parts have been replaced or refurbished, but the engine is still going. This engine can last very long with proper maintenance.
Tuning is another factor that can impact the longevity of the LBZ. Properly tuned LBZ can also last very long. But there are cases where the power is tuned up to the max, but with stock parts. That additional power and torque must be followed with good aftermarket parts supporting that extra power.
Tips For Extending the Lifespan of an LBZ Duramax
Regular maintenance of all components is the key to the long life of every engine. Besides doing regular changes and checkups, like oil and filter replacement, there are other parts to consider. The most important ones are cooling fluid checkups, turbocharger maintenance, and camshaft and exhaust inspections.
Routine Maintenance Practices
Some engine parts demand more frequent checkups. Every properly cared-for Duramax engine needs to go process of routine maintenance checks.
Fluid Checks and Changes
The board computer will regularly check fluid levels and change intervals. Nonetheless, from time to time do a visual check of the level and quality of engine oil. The oil color should be caramel or tan.
If you notice that it is completely black or dark brown, it is dirty, or it went through a lot of heating cycles. If it takes a bit of a milky note, that means that it has mixed with water. That could point to a head gasket issue. Usually, the problems are leaks, and you should think about head gasket repair.
In any case, the regular oil change interval is 10k miles. If you use the truck for heavy-duty assignments, you should change the oil even more often.
You should keep an eye on the transmission fluid. Its change interval, as we said, is 150k miles.
Filter Replacements
Filters are essential in keeping the fuel system and other key components free from debris and dirt. There are air, fuel, transmission, and oil filters. They all cover certain parts of the system. Do not let those filters get clogged. It will impact the performance of the engine. Oil filters are changed with the oil.
Timing Belt and Chain Inspections
The LBZ has a driving belt that is also called a serpentine belt. In the LBZ, it needs to be replaced every 100 to 120k miles. Symptoms of a worn driving belt are a ticking sound coming from under the hood, frequent engine misfires, stalling, or not starting at all.
Cooling System Maintenance
If you notice that the AC is not working as it should, you should do a check-up. There could be a leak either somewhere on the lines or in the radiator. If there are no leaks, the compressor is next in line for inspection. These problems can develop into very expensive repairs, especially with a dead compressor. Turn on the AC from time to time to check if everything is working as it should.
Turbocharger and Intercooler Care
The LBZ has an intercooler that helps in cooling down the high temperatures created by air compression. From time to time, it needs to be cleaned. The intercooler needs to be dismantled and disconnected from the rest of the system.
Spray it with a degreaser for a start. After that, you can additionally clean it with acetone or kerosene. Rinse it and leave it to dry for a couple of hours. When the intercooler is dry, reinstall it and reconnect it.
The best way to care for a turbocharger is to keep the cooling fluid in good condition. Also, the air filter should be clean, just like the air intake. A good thing for every day is to keep the engine running idle for half a minute before turning it off. That way, the turbo cools down to a more regular temperature.
Exhaust System Monitoring
The biggest problem with every exhaust is rust and dents. If you notice strange noises from the exhaust that you didn’t hear before, check the exhaust. There are also great aftermarket exhaust systems that will offer better airflow.
Correct Fuel and Oil Usage
There are different types of diesel on the market. We recommend using diesel with additives. Those additives can improve fuel mileage range and add additional lubrication. That is important for every engine, not only diesel ones.
When choosing oils, do not try to save a couple of dollars. Go for a better synthetic oil enriched with additives. Your engine will thank you for that.
Maintain Optimal Engine Temperature
Always keep an eye on the temperature readouts on the dashboard. It should be on the 50% value. If it is going into the red zone often, check the cooling fluid. This can happen when the truck is towing a large weight or when it is going uphill for some time. This can put a strain on the engine and push it into red.
Drive Techniques for Durability
The slow killer of every engine is long periods of idling and stop-and-go heavy traffic drives. That also helps in creating EGR valve dirt buildup. Another thing to watch out for is towing. Do not overload the truck. There are specifications for towing for every truck and engine. Follow them to keep your engine healthy.
What Are The Common LBZ Duramax Problems & Fixes?
Although the LBZ resolved some of the problems of the previous generations of Duramax engines, some issues remained. The new EGR system brought a lot of issues, and injectors are the biggest issue. Next are problems with transmission line leaks. Like the glow plugs, those are a regular but not so-big problem. Besides that, you should watch out for the water pump. Its work life is around 100k miles.
Check Out Common Problems With LBZ Duramax:
Faulty Fuel Injector
When we compare the LBZ with other Duramax generation models, it has problematic fuel injectors. You will know that the injectors when you notice white smoke coming from the tailpipe. Also, a rise in engine oil levels will point to oil mixing with fuel due to fuel injectors problems.
Other common symptoms of faulty fuel injectors are rough idling, power loss, and poor acceleration. Once the problem worsens, you will have difficulty even starting a truck. Subsequent generations of Duramax Diesel truck engines don’t have so excessive injector problems.
Glow Plug Failures
Stock glow plugs are a weak spot in these engines. If you are living in a colder climate, you will need their help more often. They are not so durable, and you must replace them every 20k miles. Fortunately, there are other glow plugs than the stock ones. They have proven to be an improvement, so you can invest some extra dollars to manage this problem better.
EGR System Concerns
The function of the EGR valve is to lower the emission of harmful NOx particles. That is done by recirculating the harmful gases through the intake system. They are practically reused. The EGR valve becomes dirty from all those gases and particles. Then it becomes clogged and that will impact engine performance.
The biggest problem is slower acceleration. As the EGR becomes more clogged, the engine will have more problems in everyday work. The LBZ often has this problem. The EGR gets clogged after around 150k miles when you will need to replace it. The price of a new EGR is around $300.
FAQs
How much HP is an LBZ
The LBZ has 360 hp. That is a significant improvement to an often called the Worst 2004-2005 “LLY” Generation that has 305 hp. There is also an improvement in torque from 605 lb/ft of torque in LLY to 650 lb/ft of torque.
Why is the LBZ engine good?
The LBZ is a favorite older Duramax engine. It is simple, and it doesn’t have any emission-restricting elements besides the EGR valve. Also, it is using an older and more reliable CP3 Bosch high-pressure fuel pump. Newer Duramax engines made after 2010 are using CP4.2 which is not as nearly good as the CP3.
The good sides of this engine are its high power output, and it can handle tuning very well. This engine is the first Duramax to employ stronger, six-speed Allison transmission. That helps in improving fuel economy and offers a comfier ride.
Final Thoughts
Sixteen years have passed since the last LBZ came from the production lines, and it is still a well-regarded engine. It is a powerful engine, that is above all free of most emission control systems. That is a huge plus for its maintenance.
This engine also brought up an improved 6-speed Allison transmission. With it came better fuel economy, and more comfort while driving on the highway. This engine is still employing the reliable CP3 fuel pump. All these great features are allowing this engine to be almost indestructible. With proper care and maintenance, you can enjoy driving your truck for years to come.
