Here Are The Dodge Cummins Years to Avoid In 2025

In 1989, Dodge invented the Dodge Cummins, a legendary invention. It has dominated the automotive industry for decades. Cummins engines were released by Dodge over a long period of time. There are some excellent model years, as well as some problematic ones. Dodge Cummins’ worst model years should be avoided if you want a pleasant driving experience.

The Dodge Cummins model years from 1991 to 1993, 1999, 2003, 2006, 2007, 2008, and 2010-2013 should be avoided because of higher problem counts and lower reliability and safety ratings.

Here’s why you should avoid these model years if you’re wondering why. Our article explains the worst Cummins model years, their problems, recall history, and also provides a list of the best Cummins model years.

Dodge Cummins Generations by Year

In 1989, Dodge Cummins was introduced for the first time. There have been five generations of 2024 Dodge Cummins from 1989 to the present.

Dodge Cummins generations by year are as follows:

1. First Generation: Dodge Cummins 1989-1993
2. Second Generation: Dodge Cummins 1994-2002
3. Third Generation: Dodge Cummins 2003-2007
4. Fourth Generation: Dodge Cummins 2007-2019
5. Fifth Generation: Dodge Cummins from 2020 onwards

1st Gen Cummins (1989-1993)

D350 and D250 were the first-generation Dodge diesel engines powered by a 5.9L 12-valve Cummins engine. It is usually used in lightweight trucks. 160 horsepower and 400 lb-ft of torque are provided by the 5.9L Cummins engine. Cummins engines of this generation are fuel efficient, achieving around 20 to 25 miles per gallon.

2nd Gen Dodge Cummins (1994-2002)

A 5.9L 12-valve engine is also available in the second-generation Dodge Cummins. The Dodge P7100 mechanical injection pump was added for the first time in this generation. This engine was also slightly modified by Dodge between 1998 and 2002.

The Cummins 24-valve engine and the Bosch VP44 electrically controlled engine were introduced at this time by Dodge. Engines of this generation have almost the same power output as engines of the first generation.

3rd Gen Dodge Ram Cummins (2003-2007)

The third generation Cummins engine offers a number of new features and some legendary changes. Due to the reliable 5.9L 24-valve engine, modern technology, and spacious cabins of third-generation Cummins engines, these trucks received high reliability ratings.

In addition to rail technology, the third-generation Dodge Cummins has a Mega Cab configuration. It is important to remember, however, that some third-gen Dodge Cummins are problematic and should be avoided. Are there any 3rd generation Cummins years you should avoid? There are many problems with the 2003, 2006, and 2007 Dodge Cummins, so it is best to avoid them. Cummins 3rd generation engines are best in 2004 and 2005.  How reliable are Cummins 3rd generation engines?

Because of their high reliability and durability, 3rd generation Cummins are reliable. Although third-generation Cummins model years should be avoided, they have fewer problems than their predecessors. For third-generation Cummins model years other than 2004 and 2005, we recommend avoiding them.

4th Generation Cummins (2007-2019)

The 6.7L Cummins engine was introduced by Dodge in mid-2007. Since mid-2007, Cummins’ 4th generation has been in operation. 370 horsepower and 800 pound-feet of torque are provided by the larger 6.7L Cummins engine. With a towing capacity of 17,600 pounds, it has great towing capabilities. Nevertheless, some Cummins fourth-generation models also share some of the common problems of previous generations.

What are the best years to avoid for Cummins 4th generation?

There are a lot of problems with Cummins in 2007, 2008, 2010, 2011, 2012, and 2013. Thus, you should avoid Cummins 4th generation engines.

5th Gen Cummins Years (2020-Present)

The most recent Cummins models are the fifth-generation. With fewer problems and high reliability, the fifth generation is one of Cummins’ best generations. It delivers an incredible 400 horsepower from its 6.7L I6 Cummins. Alternatively, the 2024 Cummins 6.7L I6 produces 420 horsepower and 1,075 pound-feet of torque.

Worst Dodge Cummins Years to Avoid

Some Dodge Cummins model years are highly problematic, despite many of them having good reputations. Therefore, these model years are considered the worst years for Dodge Cummins.

Here are the 12 worst Dodge Cummins models:

1. Dodge Cummins 1991
2. Dodge Cummins 1992
3. Dodge Cummins 1993
4. Dodge Cummins 1999
5. Dodge Cummins 2003
6. Dodge Cummins 2006
7. Dodge Cummins 2007
8. Dodge Cummins 2008
9. Dodge Cummins 2010
10. Dodge Cummins 2011
11. Dodge Cummins 2012
12. Dodge Cummins 2013

Among the factors we considered in making the above list were:

• Ratings by the NHTSA
• Reports on Consumer Issues
• Ratings from J.D. Power
• Ratings of cars on Cars.com
• Owner ratings on Edmunds
• Problems reported
• Several reliable sources provide reliability scores

Let’s take a look at each model’s years and problems:

1991-1993 Dodge Cummins

First generation Dodge Cummins were produced between 1989 and 1993. In terms of horsepower (160 hp), the first generation Dodge Cummins is not an impressive diesel engine. They became popular, however, because of their excellent torque output (400 lb-ft) which at that time was far superior to any gas engine.

However, the 1991-1993 model years of the first generation disappointed users with several issues. In these model years, handling problems, transmission problems, electrical system failures, and significant rust are the most common problems.

Dodge Cummins models of the first generation should be avoided. Because of their outdated design, reliability concerns, limited modern features, and rust issues, they are not as reliable as they should be.

1999 Dodge Cummins

Dodge Cummins’ second generation debuts with the 1999 model year. For the first year of this generation, Dodge offered a 5.9L 12-valve Cummins Turbo Diesel engine. By mid-1998, Dodge introduced a Cummins Turbo Diesel 5.9L engine with 24 valves.

The automatic transmission offers 180 horsepower and 420 pound-feet of torque with this generation’s engine. Dodge Cummins’ second generation is well known for its reliability, but the 1999 model year has some significant problems.

Among the most common problems that occur in 1999 Dodge Cummins engines are fuel injector failure, lift pump failure, VP44 injection pump problems, electrical problems, transmission problems, rust, and corrosion.

The reliability of 1999 Cummins engines is being reduced as a result of these problems. As well as its high repair cost, extensive maintenance requirements, and safety concerns, you should avoid the 1999 Dodge Cummins.

2003, 2006, and 2007 Dodge Cummins

Cummins Diesel engine with 24 valves powers the 2003 Dodge Cummins. Several problems are common in this model year, including fuel injector failures, lift pump failures, turbocharger failures, transmission failures, and electrical problems.

There are several issues with the 2003 Dodge Cummins, so you should avoid it. The lift pump and injector issues together result in a very high repair cost. There are electrical and turbocharger issues that reduce the reliability and performance of the 2003 Cummins.

There are the same issues with the 2006 Dodge Cummins as with the 2003 Dodge Cummins. There are some additional issues with these models, such as fuel system failures, high maintenance costs, steering and suspension problems, and issues with the EGR valves.

The performance of the engine is greatly reduced because of these issues. The Dodge Cummins 6.7L 24-valve Turbo Diesel engine was introduced in 2007. A stricter emissions standard is met by this engine. The 2007 model year included several upgrades, but some major problems put it on the avoid list.

2008 Dodge Cummins

This Dodge Cummins has a Cummins Turbo Diesel engine with 6.7L 24-valve displacement. Diesel Particulate Filter (DPF) and Exhaust Gas Recirculation (EGR) are part of Dodge’s advanced emission control system for this model year.

There are several problems with the model that make it on the avoid list. It is very common for this model year’s emissions systems to fail, such as the DPF clogging and the EGR system failing.

In addition to emission system problems, turbocharger failures, fuel system failures, transmission problems, and electrical malfunctions are also common in 2008 Cummins engines.

2010-2013 Dodge Cummins

Many modern features are included in the Dodge Cummins from 2010-2013. In spite of this, these years are rated as avoidable because of some of their problems.

Dodge Cummins 2010-2013 are most commonly known for the following issues:

• Failure of the Diesel Particulate Filter (DPF)
• Problems with EGR (Exhaust Gas Recirculation) systems
• A malfunction in the SCR system
• Problems with turbochargers
• Failures of injectors

The problems aren’t as severe as in earlier model years, but they still require expensive repairs. In the fourth and latest generation Dodge Cummins, the emission system is extremely complicated. That’s why the repair cost increases when they malfunction.

Dodge Cummins Reliability by Years [Complete Chart]

Some Dodge Cummins models are highly reliable, while others pose problems. For this reason, we provide reputable sources with Dodge Cummins reliability ratings every year.

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Dodge Cummins Common Problems

There are some common issues with the Dodge Cummins, especially in the avoided model years. These are some of the most common problems with Dodge Cummins:

Fuel Injector Problems

Fuel injector failure is a common complaint among Cummins users. Owners of Cummins engines report premature engine failures. This leads to reduced fuel economy, rough idling, and engine starting issues.

Dodge Cummins fuel injector failure symptoms include:

• Engine power is reduced
• Smoke that is excessively black
• Oil as fuel
• Intermittent roughness
• Problems starting the vehicle
• Return on fuel is high

Cummins’ injector failure is mainly caused by low-quality diesel fuel. Don’t use fuel that is contaminated or of poor quality. Injector failure can also be caused by poor operating conditions.

You can damage a fuel injector system by running short distances, operating at a cool temperature, idling excessively, and loading the engine lightly. It is also possible for the fuel injectors to fail when the vehicle is operated under high pressure and temperature.

In the event that fuel injectors fail, replace them all simultaneously. Make sure you choose high-quality products when replacing.

Age and Rust

Dodge Cummins engines, particularly the first and third generations, tend to age and rust over time. The problem is more likely to occur in people who drive in harsh environments such as high humidity or harsh winters. It is expensive to fix Cummins’ rust issue because it causes leaks and other serious problems.

Transmission Failure

Transmission failure is the most common problem with Dodge Cummins engines. The transmission failure issue is most prevalent in avoided model years. As a result, the engine and transmission are broken, resulting in expensive repairs.

Transmission failure symptoms in a Dodge Cummins include:

• Gear shifting is difficult
• Noises that are too loud
• Shifts are rough
• There is a burning smell

A contaminated transmission fluid causes Dodge Cummins transmissions to fail. Overheating is caused by dirty fluid.

Overheating and failure of the transmission can also be caused by low levels of transmission fluid.

Transmission failure can also be caused by bad design. The 68FE automatic transmissions on some Dodge Cummins trucks have design flaws. You should have the transmission of your Cummins trucks inspected by a professional mechanic if they are equipped with a 68FE transmission.

For Dodge Cummins transmission failure prevention, follow these steps:

• Regularly check the transmission fluid
• Parking brakes should be used
• 68FE transmissions should not be overloaded. A professional mechanic should inspect them.
• Make sure transmissions don’t overheat
• Put the gears in the right place
• Warm up the truck before driving
• A mechanic should check the transmission every year

Low Power Output

Cummins engines older than 5.9L produce low horsepower. Despite their reliability, the engines’ horsepower is low.

Electrical Malfunctions

The Cummins engine is also prone to electrical malfunctions. Cummins engines are notorious for having electrical problems between the engine and sensors. A secure electrical connection can also be a problem with wiring harnesses. Consequently, engine misfires, reduced power, and erratic performance result.

Electrical malfunctions in Dodge Cummins include:

• Warning light for battery
• Electrical components with erratic responses
• Lights that dim or are bright
• Loss of power suddenly
• Accessories that are not operational
• Fuses that have blown

Identifying the faulty parts exactly and fixing or replacing the part is the ultimate solution.

Engine Body Cracking Issues

There are some Dodge Cummins that are prone to developing cracks. This problem primarily affects the avoided years. A crack in an engine’s cylinder head or block is common. This results in coolant leaks, engine damage, and decreased engine performance. The cost of repairing such a problem is high.

Dodge Cummins Problems Count by Year

For certain Dodge Cummins model years, there were major complaints about the engine. Some Ram 2500 model years have been placed on the avoid list due to Cummins’ major problems. As a result, we have listed only the problems reported with Cummins engines fitted to Ram 2500 trucks.

Dodge Cummins problems counted by year are as follows:

There are specific Cummins engine problem numbers mentioned here. Some Cummins model years that have received many complaints have been placed on the avoid list.

Dodge Cummins Recall History by Year

The Dodge Cummins engine is usually found in Dodge Ram 2500 trucks. Some Cummins engines have major problems despite their durability. A number of Dodge Cummins-equipped Ram 2500 trucks have been recalled as a result of the problems. These Ram 2500 years with Cummins engines are listed with their recall numbers and reasons.

Based on NHTSA recall data for Dodge Cummins by year, here are the recalls:

Note: Only those Dodge Cummins years with recalls are mentioned above.

Best Years of Dodge Cummins

We have already discussed a lot of Dodge Cummins model years we should avoid. Having now learned the best year for Dodge Cummins, you should be able to buy one. The reliability and durability of many Dodge Cummins years make them safe to buy.

Listed below are the most reliable years for the Dodge Cummins:

• Dodge Cummins 2023
• Dodge Cummins 2021
• Dodge Cummins 2020
• Dodge Cummins 2019
• Dodge Cummins 2018
• Dodge Cummins 2017
• Dodge Cummins 2016
• Dodge Cummins 2015
• Dodge Cummins 2009
• Dodge Cummins 2005
• Dodge Cummins 2004

No matter if you are buying a new or used Dodge Cummins, these engines are better options. The Dodge Cummins is renowned for its immense torque, which makes it ideal for towing heavy loads. Dodge Cummins’ latest best years offer impressive fuel efficiency despite the older model. During its best years, the Dodge Cummins was known for its durability.

Are Dodge Cummins Reliable?

If you choose the best years in this article, Dodge Cummins is a reliable diesel engine. When properly maintained and cared for, a Dodge Cummins will last between 400,000 and 600,000 miles. Dodge Cummins is not only powerful and fuel-efficient, but also provides incredible longevity.

In terms of horsepower, the Cummins 6.7L Turbo Diesel produces around 420 horsepower and 1,075 pound-feet of torque. In the city and on the highway, the latest Dodge Cummins engine averages 20 mpg.

This fuel economy is truly remarkable for heavy-duty pickup trucks. The best years for Dodge Cummins have also been marked by high reliability ratings. Overall, Dodge Cummins engines perform well under heavier loads.

5.9 Cummins Specs

Cummins’ 5.9L engine was used in earlier Dodge Cummins models. The 5.9L turbocharged diesel engine is used in Cummins 2006 and earlier.

There are the following specifications for engines with a 5.9L displacement:

• Displacement: 5.9L
• Fuel system: Injection pump Bosch P7100
• Bore: 102 mm
• Stroke: 120 mm
• Compression ratio: 17.2:1
• Horsepower: 235 hp (minimum) to 325 hp (maximum)
• Torque: 460 lb-ft (minimum) to 610 lb-ft (maximum)

5.9 Cummins Years to Avoid

5.9L Cummins’ worst years are:

• Dodge Cummins 1991
• Dodge Cummins 1992
• Dodge Cummins 1993
• Dodge Cummins 1999
• Dodge Cummins 2003
• Dodge Cummins 2006

Best 5.9 Cummins Years

Cummins 5.9L engines perform best in the following years:

• Dodge Cummins 2000
• Dodge Cummins 2001
• Dodge Cummins 2002
• Dodge Cummins 2004
• Dodge Cummins 2005

5.9 Cummins Common Problems

Compared to the latest models, the 5.9L Cummins engine is very old and not as technologically advanced. Due to this, the 5.9L Cummins engine has some serious problems that need to be addressed.

Nine common 5.9L Cummins engine problems are listed below:

1. Exhaust manifolds with cracks
2. Failed fuel pumps and injectors in Cummins engines
3. Failure of the ECM
4. Slow or non-responsive accelerator pedal
5. Problems with turbochargers
6. Diesel Particulate Filter (DPF) clogged
7. Turbocharger stuck
8. Dilution of fuel
9. Failed head gasket

6.7 Cummins Specs

The Cummins 6.7L engine is one of the most legendary in the Cummins engine family. Ram 2500 and 3500 models now have an additional 6.7L Cummins engine that offers more power and torque. So, which is better, 5.9 Cummins or 6.7 Cummins? Due to its incredible power and torque output, the 6.7L Cummins is the better engine.

The latest Cummins 6.7L engine produces 420 horsepower and 1,075 lb-ft of torque. An Aisin transmission is available on Ram 3500s equipped with this high torque output. A Ram 2500 or 3500 is equipped with a 68RFE automatic transmission that produces 370 horsepower and 850 lb-ft of torque.

The Dodge Cummins engine specifications are as follows:

6.7 Cummins Years to Avoid

The 6.7-liter Cummins engine is still relatively new, and it does have some problems. There were a lot of complaints about the 6.7 Cummins in some model years. To avoid hassles while driving, steer clear of those model years.

The worst years for 6.7L Cummins are:

• (Highly problematic) 2018 Dodge Cummins
• Dodge Cummins 2020
• Dodge Cummins 2022

According to CarComplaints.com, over 2,000 complaints have been received about the 2018 Ram 2500. 266 of the complaints were engine-related. Dodge Cummins model years from this year forward should be avoided.

6.7 Cummins Best Years

With the latest Dodge 6.7L engines, reliability is high and problems are rare.

6.7 Cummins’ best years are as follows:

• Dodge Cummins 2024
• Dodge Cummins 2023
• Dodge Cummins 2021
• Dodge Cummins 2019
• Dodge Cummins 2017
• Dodge Cummins 2016
• Dodge Cummins 2015
• Dodge Cummins 2009

Cummins’ life expectancy above 6.7 is between 250,000 and 400,000 miles. You will surely have no major problems with your truck and engine if you maintain it properly. It is for this reason that the above model years are considered to be the best.

In order to prolong the life of your 6.7 Cummins, here is the maintenance schedule:

• Every 7,500 to 10,000 miles, change the engine oil.
• DEF fluid should be refilled.
• Every time you change your oil, rotate your tires
• Regularly check the tire pressure and look for unusual wear.
• Every 14,000-15,000 miles, change the air filter.
• Every 25,000-30,000 miles, adjust the parking brake,
• After 60,000 miles, replace the crankcase ventilation filter.
• Automatic transmissions should be serviced every 30,000 miles if they are used heavily or every 60,000 miles if they are used normally.
• For regular use, change the front and rear axle fluid every 30,000 miles or 60,000 miles (if heavily used).

Common 6.7 Cummins Problems

There are five common problems with 6.7L Cummins engines. The following are listed:

1. The DPF is clogged
2. Issues with turbochargers
3. Dilution of fuel
4. Problems with heater grid bolts
5. Problems with the EGT cooler

1. Clogged DPF Issues

6.7L Cummins engines commonly suffer from clogged DPFs. DEF is generally not used in Cummins engines. To reduce the emission of nitrogen oxide (NOx), the engine runs slightly rich. Diesel engines produce more soot when they run rich.

In the end, it results in a clogged DPF. DPF flashing may solve the problem in some cases. In severe cases of soot accumulation, the DPF must be replaced.

2. Turbocharger Failure

It is not common for Dodge Cummins engines to have turbocharger failures. Nevertheless, because this is a major issue, it must be addressed. Turbocharger failure is characterized by whining sounds, slow spooling, poor performance, and smoke from the exhaust. A severe problem may require rebuilding the 6.7L Cummins engine.

3. Fuel Dilution Issues

There are some 6.7L Cummins that suffer from fuel dilution issues. It is expected that fuel dilution will occur at a certain level. There are several problems associated with excessively diluted oil in the engine.

The following are easy ways to prevent the 6.7L Cummins engine from diluting fuel:

• The engine needs to be warmed up
• Analyses of oil
• Idling should be minimized

4. Heater Grid Bolt Issue

Like glow plugs, heater grid bolts are components of diesel engines. During cold starts, it heats the air that passes over the intake manifold and assists the engine in starting. With 6.7L Cummins engines, Ram 2500 and 3500 trucks equipped with heater grid bolts are prone to failure.

It is usually not noticeable that there is a problem with the heater grid, but it compromises the performance of the vehicle in general. Check the heater grid on the intake manifold if you experience poor performance.

5. EGR Cooler Problems

The 6.7L Cummins engine is notorious for having EGR problems. EGR cooler failures are characterized by white smoke coming from the exhaust. In most cases, replacing the EGR is the best solution, which costs around $120.

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FAQs

Is the 5.9 Cummins Reliable?

A 5.9L Dodge Cummins engine is reliable and powerful. Longevity and durability are two of the best features of the 5.9L engine. Fuel economy is excellent with this engine. This engine produces excellent torque. As a result of all these factors, the 5.9L engine is a reliable one.

How Many Miles Can a Cummins Diesel Last?

When properly maintained and cared for, a Dodge Cummins engine can last between 350,000 and 400,000 miles. Take good care of your Cummins engine if you want to reach this milestone.

Maintaining a Dodge Cummins engine has already been discussed above. You can get a better understanding of maintenance by checking the guidelines.

‘5.9 or 6.7 Cummins’ Which is Better?

6.7L Cummins are superior to 5.9L Cummins in overall performance. In some aspects, such as reliability, durability, and fuel economy, the 5.9L Cummins wins over the 6.8L Cummins.

In contrast, the 6.7L engine has an advantage in some areas, such as power and torque output, responsive turbocharger, advanced technology, and quieter operation.

You should choose the 6.7L Cummins if you want advanced technology, better horsepower and torque, and a responsive vehicle. You should choose the 5.9L Cummins if you are looking for a proven and reliable engine.

Which Cummins ISX Years to Avoid?

Considering our data, Cummins ISX model years 2004-2007 and 2010 should be avoided. There is a high rate of EGR system failure and turbocharger failures during these model years. It is also recommended that you avoid the 2008 Cummins ISX.

Nevertheless, we believe the 2008 Cummins ISX is less problematic than the 2004-2007 or 2010 Cummins ISX.