Cummins ISX Repair: Most Common Problems

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Iron Buffalo Truck & Trailer
September 15, 2023
Cummins ISX Repair: Most Common Problems

Cummins ISX is an inline 6-cylinder turbocharged diesel engine with about 600 horsepower and 2050 pounds-feet of torque. ISX is the successor of the legendary N14 engine designed by Cummins. It's currently used in many heavy-duty trucks like the Freightliner M2 and the International DT-466.

Besides being a superior truck engine because of its torque and horse, the engine is also durable. However, like many other engines, quite a few things can go wrong with the ISX engine.

Today, we'll look at the 5 most common problems with the Cummins ISX engine and why drivers prefer this engine. 

Cummins ISX Specs That Make It Unique

  • System weight: 3093lbs
  • Dry weight: 3021 lbs
  • Aftertreatment: 72lbs
  • Oil capacity: 14 gallons
  • Clutch engagement torque: 1000lb-ft
  • Engine speed: 2000-2100 RPM

Most Common Repairs for Cummins ISX

1. Turbocharger Problem

Turbochargers are one of the most important aspects of diesel engines. They are responsible for providing inlet air necessary for boosting engine performance. 

One of the most common complications that these turbochargers encounter is the dreaded turbo-lag issue. Turbo lag is a term that describes slowed throttle response experienced before the turbocharge kicks in—providing extra power to the engine.

The problem can be due to lubrication issues, clogged filters, or other engine failures that result in reduced fuel intake. Turbo lag problems are generally known to result in engine damage, meaning the earlier you diagnose the issue, the better. 

How to diagnose turbocharger problems:

  • Excessive oil consumption
  • Low performance
  • Excessive smoke
  • Low power
  • Loose shaft

2. EGR Problem 

All engines produce a toxic chemical called nitrogen oxide. With emission standards becoming stricter, many vehicles have an exhaust gas recirculation system that cycles back gases passed out of the engine. In turn, this reduces the levels of nitrogen oxide emitted.

The major part of the system is the EGR valve. When the valve has a problem, it interferes with the operation and flow of the system. In turn, this causes performance-related problems as well as increased nitrogen oxide emission. 

How to diagnose EGR valve problems:

  • Engine performance problems: A malfunction EGR valve leads to engine performance problems like reduced acceleration and makes fuel less efficient.
  • Check Engine Light: Whenever your vehicle computer detects problems with your EGR valve position or circuit, it will illuminate the Check Engine Light to let you know there's an issue with the valve. 
  • Rough idle: rough idling occurs when your vehicle doesn't feel smooth at all. For instance, the RPMs will move up and down. You can easily detect rough idling whenever you start your car.

3. Faulty Camshafts

A camshaft is a rotating shaft or rod that opens and closes the intake and exhaust valves depending on engine speed, loads, and throttle position. 

Camshaft problems are a major cause of engine malfunction. In the Cummins ISX engine, camshaft problems are commonly caused by faulty rocker arms. When these arms lack proper oil flow, they smack the cam lobes causing them to flatten. As a result, it might damage your engine or even blow it up.  

The only way to tell that your camshafts are faulty is if you notice a change in your engine performance. The good news is that you can solve the issue by changing both the camshaft and the rockers. Therefore, instead of buying a new engine, bring it to our professionals for repair.

4. Timing Wedge Problems

A timing wedge is a piece of metal that goes in-between the cam gears. It's designed to catch the oil that falls from the cam follower and push it back up to lubricate the cam lobes. It also compresses the oil in the sump to go through the pump housing and into the engine block.

When the timing wedge fails to work properly, it can lead to confusion in an engine. In turn, this leads to delays in the opening of the valves.

To avoid problems with the timing wedge, you'll need to change your oil filter. If the problem requires you to retime the engine, google" Cummins ISX repair shop near me" or "Adrenaline Diesel repair shop near me" for immediate assistance from our repair experts. 

5. Problems with Cylinder Liners

Cummins ISX engines are usually designed to operate with factory-installed cylinder liners. However, if the cylinder liner drops into the engine's borehole, there is potential for serious engine damage. 

The cylinder can crack and drop due to:

  • Incorrect installation
  • Erosion and corrosion
  • Presence of foreign bodies in its combustion space
  • Poor cooling
  • Improperly fit piston(s) 

Some signs of an issue with your cylinder liners include a drop in pressure, coolant leak, or overheating the engine.

Why Do Drivers Prefer the Cummins ISX Engine?

Many people are curious about which engine they should buy for their motorcoaches and trucks. Less familiar options might seem appealing at first, but there's one engine that stands out in most instances: Cummins ISX. 

Here are some reasons most truck owners prefer this engine: 


Cummins engines are one the most fuel-efficient on the market today. They generate more power per liter of fuel consumed than many other brands. 

One way Cummins engines generate this amount of power is by using Two-Stage turbochargers


Tractor engines are usually subjected to wear and tear, which causes operational issues for many drivers. However, the Cummins ISX components allow it to withstand more pressure and are corrosion-free. It's made from tough, durable materials and designed to last for years on end.

Low Maintenance Costs

If you are looking for an engine that will provide you with long-term benefits, ISX engines are undoubtedly the best option. These engines require less maintenance than other engines on the market. 

They are specifically designed to provide you with longevity, an incomparable driving experience, and low operating costs. 

Repair Your Cummins ISX Today 

If you're having an issue with your engine, you've probably found yourself searching "Cummins ISX repair shops near me" on the internet. Well, if you reside or happen to be in Denver, Colorado, we are here to help you.

Reach out to our professionals at JE-CO Truck& Trailer for all your Cummins ISX repairs.