Which 6.7 year old Cummins to avoid and why? (Explained) (2023)

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Cummins engines are widely known for their durability and reliability and the Cummins 6.7 or B6.7L is one of the best received engines. The 6.7 Cummins is a diesel engine from the latest Cummins B-series, featuring a 24-valve in-line six-cylinder turbocharged diesel engine that delivers unmatched performance and reliability.

However, every engine has its fair share of limitations, and the 6.7 Cummins is no exception. As a result, general problems likeclogged diesel particulate filter, faulty turbocharger, faulty head gasket or EGR coolerYou can pass.

Continue reading the following article to find out exactly why 6.7 Cummins engines are best to ignore and which model year 6.7 Cummins you should avoid.

Aproximadamente 6.7L Cummins

Cummins Engine Company was originally founded in1919but was rebuilt as a Cummins in2001and Cummins is one of the most trusted companies offering some legendary engines.

Cummins B series is one of the most powerful and reliable engine series. Also,widely used in automobile equipment such as trucks, buses, and construction machinery.

One of the most well-known and widely used B-series engine models is the 6.7L. HeIn mid-2007, the RAM 2500 and 3500 trucks were officially presented, the first model with a 6.7 Cummins engine..

The 6.7 Cummins is available inStandard output (ST) and high output (HO). Also available and able to offer in different size options.150 to 420 horsepower, as well as660-850 lb-ft Drehmoment.

Later, the 6.7 engine was used in various other medium-duty trucks, RVs, and school buses.

What particular vehicle models have 6.7 Cummins?

The following vehicle models are equipped with the 6.7 Cummins engine:

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  • Ram 2500 Heavy Duty Pickup Models
  • Ram 3500 Heavy Duty Pickup Models
  • 3500 Chassis and Cab Models
  • 4500 Chassis and Cab Models
  • 5500 Chassis and Cab Models

Cummins Worst 6.7 Years to Avoid: (List of Years)

Cummins B-Series for providing a solid, powerful and reliable diesel engine.

Some of the Cummins B engine models are recognized as the most popular and reliable diesel engines in the world..

Technically, no engine can be flawless and perfect, and the 6.7 Cummins also falls into this category.

Even the 6.7 engine was quite famous in its early days, when most users seemed to enjoy their ride with this engine very much.

But the problems eventually become unavoidable and users often complain about them.Steering, engine, electrical, suspension or exhaust problemsby engine potential 6.7Design, manufacturing and techniqueHe is lost.

Therefore, avoid 6.7 engines from the following years unless you are willing to experience the main problems with these models:

years to avoid

important reasons

2007 Dodge 6.7 Cummins

1.Due to general steering problems and extreme front axle jerk, the tie rod and push rod fail prematurely.

2.Engine problems such as visible oil leaks, check engine light staying on for no reason, or engine failure.

3.Electrical issues like faulty or faulty TIPM, difficulty starting the engine.

2008 Dodge 6.7 Cummins

1.Due to death wobbles, unusual crankshaft noise and leaks in the steering gear.

2.In addition, exhaust, suspension and engine damage was found and reported.

2011 Dodge 6.7 Cummins

1.Due to serious suspension problems such as broken tie rod and dead wobble

2.Engine problems, such as camshaft failure, hard starting, and low speed or visible loss of engine power

Top 5 6.7 Cummins Problems:

In this section, I will address and discuss in detail the five most common Cummins 6.7 engine problems that made it unreliable and preventable.

Before moving on to the main discussion, let's take a look at the main issues and the estimated cost to fix them.

Problem:Estimated repair costsEstimated amount of work
1. DPF clogging problems$2,000 – $3,000 (including labor)
2. Turbocharger failure5.303 $ – 7.597 $$581 – $733
3. Head gasket problems2.680 $ – 2.854 $$661 – $834
4. Fuel dilution problems$350 or more (including parts and labor)
5. EGR cooler problems$2,700 (including labor)

1. DPF clogging problems

The 6.7 Cummins engine has a very common and significant problem reported by most users and car experts. After his actual experience,Die The diesel particulate filter or DPF tends to clog quite quickly and frequently.

Users mentioned common symptoms likeLoss of engine power, long cranking, reduced power mode, turbo malfunction, and all of a sudden engine trouble codes.

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The manufacturer reportedly avoided using Diesel Exhaust Fluid (DEF) in the 6.7 engines. Due to the lack of DEF, the engine is said to run a little richer to reduce NOx emissions. This process allows more particles or soot to enter, eventually clogging the DPF.

These DPF clogging issues were on theprevious models,and to avoid further damageImplementation of multiple flashes of PCM.

In 2013, the manufacturer developed 6.7 engine models.Equipped with SCR emission control systems and Diesel Exhaust Fluid, which helps to effectively reduce particulate matter and minimize the possibility of DPF clogging.

Is this problem expensive to fix?

You can reportedly fix the DPF problem at any professional service center or shop$2.000-$3.000and labor costs are included in the estimated cost amount.

Retrofittable diesel particulate filters are available from approx.1.000 $or just over $1,000.

2. Turbocharger failure

Another most frequently mentioned Cummins 6.7 engine problem is turbo malfunction or complete turbocharger failure, which happens most of the time.on earlier models engine users 6.7.

Since turbochargers naturally take a great deal of abuse, malfunction or failure can be unavoidable over time.

Other common symptoms wereslow coil, poor performance, excessive exhaust smoke, oil leak, and howling noises.

Aside from complete turbocharger failure, a few other commonly turbo related issues were identified.premature seal problem or oil leakage from seals, excessive shaft clearance due to premature bearing wear, sticking VGT parts, and turbine or compressor wheel wear.

Consumers also mentioned that the most common turbo problems occur approximately120.000miles

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Is this problem expensive to fix?

It is one of the most expensive Cummins 6.7 engine repairs. Maintenance by a professional maintenance center reportedly costs between$5,303 y $7,597, and labor costs are kept in the middle$581 y $733.

New OEM turbochargers for 6.7 Cummins are available north at1.000-1.500 $.

3. Head gasket problems

According to numerous user reports and expert opinions, the 6.7 Cummins engine isvery often encounter head gasket problems, and consumers have to deal with maintenance very often.

This head gasket failure is most likely due to either the horsepower and torque the manufacturer puts out for the 6.7 or high cylinder pressures that could be causing the problems.

Users also reported common symptoms like wSmoke coming from the exhaust, an unusually sweet smell as a result of burning coolant, a blown head gasket that allowed oil to mix with the cooling system, and instant overheating due to high pressure in the coolant or a leak of refrigerant flows into the tank.

The good news, however, is that the 6.7 engine head gasket failure problem is less common and causes less severe damage than the previously introduced 5.9 engines.

Is this problem expensive to fix?

It is another expensive repair and taking your vehicle to a professional workshop will cost you in between.$2,680 y $2,854, and labor costs are kept in the middle$661 y $834.

4. Fuel dilution problems

Reports claim that the encounterProblems with fuel dilution in 6.7 diesel engine oil are somewhat natural due to the way the manufacturer designed and built the engine to manage regeneration..

In the regeneration management process, the engine is designed to capture foreign particles in the DPF and burn them for cleaner emissions.

Unfortunately the 6.7 enginedon't use 7heInjector to lift fuel into the exhaust and as the cylinder exhaust rotates, the 6.7 engine's fuel injectors spray a fair amount of fuel into the exhaust stream..

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As a result,This entire process allows the fuel to stick to the cylinder wall and mix with the oil to cause dilution..

Is this problem expensive to fix?

cummins released onenew oil analysis programand under this program you can do oil analysis in approx.$350 or more(including oil, oil filter, labor and disposal costs)

5. EGR cooler problems

EGR cooler failure is not a new problem unique to 6.7 Cummins powered vehicles and is a fairly common problem on most modern diesel trucks or other similar vehicles.

However, most long-time owners of diesel engines are already aware of this problem, and tEGR problems occur mainly because 6.7 engines are designed and built in such a way that the EGR valve and cooler must encounter various problems, especially on high mileage vehicles..

Luckily this problem, like all the other big problems in the 6.7 engine, has an easy solution. If the problem arises visibly, just clear the EGR system and another solution is to clean the EGR valve or just replace it.

Is this problem expensive to fix?

If you take your vehicle to a professional workshop, it will cost you approx.2.700 $(Including labor costs).

It is a relatively inexpensive repair service because professional help is not always required if the maintenance schedule is adhered to.

How long does a Cummins 6.7 last?

A Cummins 6.7 engine has a life expectancy of between250.000 y 350.000miles

How long do Cummins 6.7 Cummins injectors last?

With regular maintenance and proper care, the injector on a Cummins 6.7 engine can last up to250,000 or a few more miles.


The Cummins brand is internationally recognized for offering high quality diesel engines, available in a variety of sizes to meet the standard of supplying products that meet most equipment application needs.

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But in addition to the excellent quality of these engines, engines like 6.7 also have significant problems and expensive repair work. Therefore, do not rush and take your time to make the best decision.

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