Fuel injectors in a Cummins ISB 6.7L common rail system don’t just deliver fuel.
They control timing, pressure, atomization, and combustion efficiency – all within milliseconds.
When an injector begins to fail, it’s not always obvious at first.
But internally, the failure has already started.
Continue reading Cummins ISB 6.7L Fuel Injectors: What Actually Fails Inside a Common Rail Injector
If your Cummins ISX or QSX is overheating, losing coolant, or showing signs of combustion issues, the problem may be deeper than a gasket or sensor.
It could be your cylinder head.
And when a cylinder head starts to fail, it doesn’t take long before it affects the entire engine.
Continue reading Cummins ISX, QSX Cylinder Head: Symptoms, Failure Causes, and Replacement Guide
The Cummins ISL G natural gas engine is built for a different type of combustion.
And that difference is exactly why the cylinder head fails the way it does.
Unlike diesel engines, ISL G failures are not typically caused by pressure.
They are caused by heat, material fatigue, and valve seat wear.
Continue reading Cummins ISL G Cylinder Head Failures: Why Valve Seats Drop and How to Prevent It
The cam follower in a Cummins L10 is a small component with a very large job.
It directly transfers motion from the camshaft to the valve train.
And when it fails, it doesn’t just affect performance – it can lead to catastrophic engine damage.
In the Cummins L10 valve train, the camshaft does not directly actuate the valves.
Instead, motion is transferred through a cam follower (cam lever with roller).
This component:
The roller rides directly on the cam lobe, making this a high-load, high-contact stress interface.
The Cummins L10 uses a roller-style follower to reduce friction and wear.
Compared to flat tappets, roller followers:
However, this design introduces a different failure risk — roller bearing failure.
The cam-to-roller interface experiences extreme contact pressure.
This is a classic Hertzian contact stress scenario, where:
Under normal conditions, a hydrodynamic oil film separates the surfaces.
But when lubrication is compromised, metal-to-metal contact occurs.
Cam follower failures typically start small but escalate quickly.
Common failure modes include:
Once the roller stops rotating:
This is where failure becomes severe.
A seized roller creates:
This leads to:
Eventually, this can damage:
The cam follower depends entirely on proper lubrication.
Oil must:
Failure causes related to lubrication include:
Without lubrication, failure accelerates rapidly.
A failing cam follower rarely fails alone.
It creates a chain reaction:
In severe cases, this can lead to:
Early detection can prevent major damage.
Watch for:
These symptoms often appear before catastrophic failure.
Cam followers should always be inspected during an overhaul.
Key checks include:
Reusing worn components increases the risk of immediate failure.
Replacement is recommended when:
It is often best practice to replace followers when replacing the camshaft.
If you’re rebuilding your engine or diagnosing valve train issues, cam followers should not be overlooked.
At Highway and Heavy Parts:
The cam follower may seem minor.
But it directly affects:
Ignoring it can lead to major repairs.
Proper function depends on correct operation across all components.
👉 Maintain Proper Oil Quality And Pressure
👉 Inspect Valve Train Components During Service
👉 Replace Worn Components Before Failure Occurs
Call 844-304-7688 to speak with a diesel parts specialist
or visit highwayandheavyparts.com to find the right rebuild kit for your engine.
From diagnosis to delivery, Highway and Heavy Parts has your back.
Noticing an increase in oil consumption in your Cummins ISM? Are you hearing knocking sounds or is your engine losing compression?
Continue reading Inframe Engine Rebuild Kit for Cummins ISM (4918787)
Engine sputter, misfiring, or an engine that won’t start can cause major frustration with the fuel system on your Cummins ISM diesel engine. It’s time to stop buying fuel injectors from a cleaning shop!
Continue reading Cummins ISM Celect Fuel Injector (EX631756)
Engine sputter, misfiring, or an engine that won’t start can cause major frustration with the fuel system on your Cummins ISM or M11 diesel engine. It’s time to stop buying fuel injectors from a cleaning shop!
Continue reading Cummins ISM, M11 Celect Fuel Injector (4902921PX)
Is your aftertreatment system using too much DEF fluid or causing a white build-up on your exhaust pipes? Has this resulted in different engine codes and your truck falling out of emission compliance? Results like this end up taking you off the road, and money out of your pocket.
Continue reading Cummins ISX, ISB, ISC, ISL Dosing Module (2888173)
This is our standard, no-frills cylinder head. It comes loaded with all the essential components you need in an OEM quality cylinder head, and costs up to 50% less. But we didn’t stop there!
Continue reading Cummins ISL Cylinder Head Overview (N3969722VS)
This is our standard, no-frills natural gas cylinder head. It comes loaded with all the essential components you need in an OE-quality cylinder head, and costs up to 50% less. But we didn’t stop there! This cylinder head has some serious improvements over the original OEM casting.
Continue reading Cummins ISLG Natural Gas Engines Cylinder Head (4933818)Beyond the popular N14, ISX, and X15 engines, Cummins has produced numerous other diesel and natural gas engines that power commercial vehicles, industrial equipment, and marine applications worldwide. These diverse engine platforms include the ISM, M11, C Series, B Series, and specialized natural gas variants, each engineered for specific applications and performance requirements. While these engines may not be as widely recognized as their highway counterparts, they remain critical powerplants in various industries and require specialized parts and maintenance expertise.
Each Cummins engine family features unique design characteristics, component specifications, and service requirements. The ISM and M11 engines, for example, share similar displacement but have distinct fuel system designs that require specific fuel injectors and related components. Natural gas engines incorporate specialized cylinder heads, ignition systems, and fuel delivery components that differ significantly from their diesel counterparts. Understanding these differences is essential for proper maintenance and repair.
Proper maintenance of these diverse Cummins engines requires attention to fundamental systems that ensure reliable operation. Oil pumps serve as the lifeblood of any engine, circulating lubricant to critical moving parts and preventing catastrophic damage from inadequate lubrication. Quality oil pumps maintain consistent pressure and flow rates essential for engine longevity.
Gaskets and sealing components play a vital role in engine integrity, preventing fluid leaks and maintaining proper compression ratios. While often overlooked, failing gaskets can cause expensive secondary damage if not addressed promptly. Quality gasket sets ensure proper sealing across all engine systems.
Fuel system components, particularly fuel injectors for ISM and M11 engines, require precision manufacturing to deliver optimal fuel delivery and combustion efficiency. Aftertreatment systems in newer engines also demand specialized components to maintain emissions compliance and prevent costly DEF consumption issues.
Natural gas engines require unique cylinder heads designed for different combustion characteristics and operating temperatures. These specialized components often feature improved designs over original equipment, providing enhanced durability and performance while maintaining cost-effectiveness for fleet operators and industrial users.
