If you’re experiencing problems with your common rail fuel injectors, you’ve probably noticed a difference in the way your diesel engine performs. And you’re probably eager to get the issue taken care of.
Continue reading An In-Depth Look at Diesel Engine Common Rail Fuel Injector ProblemsCategory: Blog – Diesel Engine Diagnostics
Converting a Cummins Low-Flow Cooling System to High-Flow: What It Actually Takes
Older Cummins engines – especially Big Cam and NTC/N14-era platforms – used two different cooling system designs:
- Low-flow cooling systems
- High-flow cooling systems
These systems are not just minor variations.
👉 They are fundamentally different in how coolant moves through the engine.
And that matters when you’re trying to solve overheating – or considering a conversion.
Continue reading Converting a Cummins Low-Flow Cooling System to High-Flow: What It Actually TakesHow to Diagnose Diesel Engine Belt Noise
Diesel engine belt noise is one of the most common drivability complaints on heavy-duty trucks and equipment.
The noise may sound like:
- A squeal
- A chirp
- A screech
- A grinding or growling sound
However, the belt itself is not always the actual problem. In many cases, the noise is caused by:
- Improper belt tension
- Pulley misalignment
- Worn bearings
- Oil contamination
- Failing accessory components
Accurately diagnosing diesel engine belt noise is important because replacing only the belt may not solve the root issue.
Continue reading How to Diagnose Diesel Engine Belt NoiseWhy Oil Starvation Destroys Diesel Turbochargers
A turbocharger failure can look like a bad part.
Loss of power. Smoke. Noise. Oil leaking. Shaft play.
But in many heavy-duty diesel engines, the turbocharger is not the real starting point of the failure. The damage often begins somewhere else in the lubrication system.
The number one issue that destroys turbochargers is oil starvation. When a turbo does not receive a steady supply of clean, pressurized oil, internal damage can happen fast: sometimes within seconds under load.
Continue reading Why Oil Starvation Destroys Diesel TurbochargersCamshaft Failure Analysis: What Causes Excessive Lobe Wear (C15 Focus Included)
We all know how important camshafts are to engine performance – and when they fail, the damage can go far beyond the camshaft itself.
Whether you’re running a general diesel platform or a Caterpillar C15 diesel engine, one of the most common issues is camshaft lobe wear and pitting.
👉 And once it starts, it does not slow down – it accelerates.
Connecting Rod Failure Analysis: Common Causes, Symptoms, and Prevention
Connecting rods are among the strongest components inside a diesel engine. Built from forged steel or powdered metal, they are designed to withstand enormous combustion pressures and transfer thousands of pounds of force every second from the piston to the crankshaft.
Because they are so robust, connecting rods rarely fail on their own.
When a connecting rod bends, breaks, or suffers bearing damage, it is almost always the result of another underlying problem. Oil starvation, bearing failure, overheating, improper assembly, hydrolock, overspeed, or using outdated components during an engine overhaul can all lead to connecting rod damage.
That is why replacing a damaged connecting rod without identifying the original cause often leads to another expensive engine failure.
This failure analysis walks through one real-world example of connecting rod damage, explains why it happened, and highlights other common causes of connecting rod failure so you can diagnose the root cause—not just replace broken parts.
Quick Takeaway: Connecting rods rarely fail first. Most failures begin with another issue, such as bearing damage, low oil pressure, oil starvation, overheating, hydrolock, or an incomplete engine overhaul. Always determine why the connecting rod failed before replacing components.
Continue reading Connecting Rod Failure Analysis: Common Causes, Symptoms, and Prevention PACCAR MX-13 Common Engine Problems & Solutions
The PACCAR MX-13 is used in many Kenworth and Peterbilt heavy-duty trucks, especially in long-haul and fleet applications.
Like any modern diesel engine, it depends on several systems working together:
- Fuel System
- EGR System
- Turbocharger
- Cooling System
- Sensors and ECM
- Aftertreatment System
When one of these systems starts to fail, the symptom may show up as low power, derate, rough idle, hard starting, excessive regens, or poor fuel economy.
The key is not just replacing the part that triggered the fault code: it is identifying why the issue happened in the first place.
Continue reading PACCAR MX-13 Common Engine Problems & SolutionsPiston Pin Failure Analysis: Common Causes, Symptoms, and Prevention
The piston pin—also known as the wrist pin or gudgeon pin—is one of the hardest-working components inside a diesel engine. Although it’s relatively small compared to the piston or connecting rod, it transfers tremendous combustion forces every time the engine fires.
Despite its strength, piston pin failures do occur.
When they do, the damage is usually severe. Excessive wear, galling, scoring, discoloration, or seizure often indicate another underlying problem, such as poor lubrication, overheating, incorrect clearances, contamination, or improper engine assembly.
Replacing the damaged piston pin alone rarely solves the problem.
Instead, it’s important to determine why the piston pin failed before rebuilding the engine. Otherwise, the same conditions that damaged the original components may quickly damage the replacement parts as well.
This failure analysis explains how piston pins work, the warning signs of failure, what causes them to wear prematurely, and how proper diagnosis can help prevent repeat engine failures.
Quick Takeaway: Piston pin damage is usually a symptom—not the root cause. Most failures begin with poor lubrication, overheating, contamination, or incorrect clearances. Before replacing damaged pistons or piston pins, identify what caused the failure to prevent it from happening again.
Continue reading Piston Pin Failure Analysis: Common Causes, Symptoms, and Prevention Piston Ring Failure Analysis: Common Causes, Symptoms, and Prevention
Piston rings are small compared to many other diesel engine components, but they have a major impact on engine performance, oil control, compression, and long-term reliability.
When piston rings fail, the symptoms can show up quickly: excessive oil consumption, blow-by, loss of power, poor compression, or blue exhaust smoke. The difficult part is that piston ring failure is often not the true root cause. In many cases, the rings were damaged by another issue inside the engine, such as improper installation, abrasive contamination, overheating, poor lubrication, incorrect cylinder finish, or an improper break-in procedure.
That is why failure analysis matters.
Replacing the rings without understanding what caused the failure can lead to the same problem happening again.
If your diesel engine is experiencing piston ring failure, the goal should not be to simply identify the broken part. The goal should be to understand why the ring failed, what other components may have been affected, and what needs to be corrected before the engine goes back together.
Quick Takeaway: Broken piston rings are usually the result of another underlying problem, not the root cause. Improper installation, abrasive contamination, overheating, poor lubrication, incorrect cylinder finish, and poor break-in procedures can all shorten piston ring life. Correcting the root cause is essential before installing new rings.
Continue reading Piston Ring Failure Analysis: Common Causes, Symptoms, and Prevention Diesel Fuel Contamination Problems: What’s Lurking in Your Fuel
Diesel fuel contamination problems are more common than most people realize.
Even when it meets specification at delivery, contamination can develop during storage, transport, or in your own fuel system. Over time, these contaminants affect fuel lubricity, combustion quality, and component life.
The most damaging contaminants are not always visible, but they leave very real mechanical consequences.
Continue reading Diesel Fuel Contamination Problems: What’s Lurking in Your FuelInternational/Navistar DT466E Inframe Rebuild Kit: Wet Sleeve Wear, HEUI System Impact, and What to Verify Before Installation
The International/Navistar DT466E is known for its durability – but like all wet sleeve diesel engines, its longevity depends on cooling system condition, liner integrity, and fuel system performance.
When these engines start showing signs like blow-by, coolant loss, or hard starting, the issue is rarely isolated.
It’s typically the result of cylinder wear, liner sealing issues, or HEUI system inefficiencies affecting combustion.
If you’re planning an inframe rebuild, understanding these failure points is critical to avoiding repeat repairs.
Continue reading International/Navistar DT466E Inframe Rebuild Kit: Wet Sleeve Wear, HEUI System Impact, and What to Verify Before InstallationDiesel Engine Blow-By: How Much Is Normal and When Should You Be Concerned?
If you’re seeing vapor coming from the breather or crankcase vent, you’re probably asking:
Is this normal or is my engine going bad?
That’s where a lot of confusion comes in.
Some blow-by is completely normal. But excessive blow-by can point to internal wear, poor sealing, or a bigger issue building over time.
The key is knowing the difference.
Continue reading Diesel Engine Blow-By: How Much Is Normal and When Should You Be Concerned?
