Category: Diesel Tips and Diagnostics

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Cummins ISX Inframe Rebuild Failure: Why Your New Liners Aren’t Sealing (And How to Fix It)

You finished the inframe. New liners, pistons, rings – everything looks right.

But now you’re seeing:

  • Blow-By
  • Oil Consumption
  • Low Compression
  • Or Worse… It’s Smoking Under Load

This isn’t uncommon on Cummins ISX engines – and it usually comes down to one issue:

Improper liner protrusion and ring seating during install.

If you don’t get this right, your rebuild won’t last – no matter how good your parts are.

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DD15 Diesel Engine Pistons: How They Control Blow-By and What Causes Failure

Blow-by is not just a symptom.

It is a direct result of combustion pressure escaping past the piston assembly.

On a Detroit Diesel DD15, controlling blow-by comes down to one thing:

How well the piston, rings, and liner seal under load.

If that seal fails, everything else starts to follow.

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Cummins ISX Crankshaft Failure: Signs, Causes, and What to Do Before It Costs You an Engine

When a Cummins ISX starts running rough, vibrating, or misfiring, most people don’t immediately think about the crankshaft.

That’s the problem.

Because by the time the crankshaft shows obvious symptoms, the damage is usually already happening inside the engine – and it doesn’t take long before it turns into a full rebuild.

If you’re dealing with vibration, low oil pressure, or unusual engine noise, this is one issue you don’t want to ignore.

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Caterpillar 3406E, C15, C15 ACERT Spacer Plate: How It Controls Liner Height and Sealing

The spacer plate in a Caterpillar 3406E, C15, and C15 ACERT is not just a structural component.

It is a critical part of the engine’s sealing system.

It directly controls:

  • Cylinder Liner Protrusion
  • Head Gasket Clamping Force
  • Combustion Sealing Integrity

If the spacer plate is worn, damaged, or machined incorrectly, the entire sealing system is compromised.

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Cummins Diesel Engine Serial Numbers

Look at your rocker cover: you’ll probably find your Cummins ISB engine serial number. You might also find it on the side of the gear housing. If you have a Cummins ISM engine, the serial number is on the rocker housing on the fuel pump side.

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Diesel Cylinder Head and Engine Rebuild Kit Bundle Sale

Cylinder Head and Rebuild Kit Bundle

Highway and Heavy Parts is excited to introduce our new diesel engine parts bundle sales promotion. It includes diesel cylinder heads and diesel engine add-ons for all major heavy-duty truck and equipment manufacturers. If you need a cylinder head for your Cummins, Caterpillar, Detroit Diesel, or other heavy-duty diesel engine, you can get everything you need to do the job right and save some money.

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How to Clean EGR Pressure Ports in Diesel Engines (Without Causing Damage)

EGR pressure ports are small, but they play a critical role in how a diesel engine manages emissions and airflow.

When they clog, it can lead to:

  • Fault codes
  • Engine derate
  • Poor performance
  • Misdiagnosed EGR system failures

Cleaning them correctly matters just as much as diagnosing the issue.

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Detroit Diesel Series 60 14L Turbocharger: Symptoms, Failure Causes, and When to Replace

The turbocharger on a Detroit Diesel Series 60 14L engine does more than add power.

It controls airflow, and airflow controls combustion.

When the turbo isn’t performing correctly, the entire engine starts to fall out of balance.

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Caterpillar C15 and 3406E Oil Pump: Symptoms, Failure Causes, and When to Replace

Low oil pressure isn’t something you ignore on a diesel engine.

On a Caterpillar C15 or 3406E, it’s often a warning sign that something deeper is going wrong inside the engine.

And in many cases, the issue starts with the oil pump.

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Before You Replace That Caterpillar Turbo, Check Your Injectors First

When a Caterpillar engine starts losing power, producing excessive smoke, struggling with recurring DPF issues, or experiencing turbocharger problems, the turbocharger is often the first component blamed.

Sometimes the turbocharger is the problem. But many times, it is simply the victim.

What many technicians and equipment owners don’t realize is that fuel injectors and turbochargers work together as part of the same combustion process. When injector performance begins to decline, the effects can spread throughout the entire engine, eventually impacting the turbocharger, aftertreatment system, fuel economy, and overall performance.

Before replacing another turbocharger, it may be worth taking a closer look at the fuel system.

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What Happens When a Diesel Engine Sits Too Long? (Fuel, DEF, and Internal Damage Explained)

Diesel engines are built to run – not sit.

At Highway and Heavy Parts, we regularly work with engines that come out of storage with unexpected performance issues. In many cases, the root cause isn’t a failed part: it’s what happened while the engine wasn’t running.

Whether it’s a backup truck, seasonal equipment, or a unit waiting on work, extended downtime can quietly create problems that don’t show up until the engine is put back into service.

And in many cases, those problems get misdiagnosed.

From fuel degradation to DEF crystallization and internal wear, here’s exactly what happens when a diesel engine sits too long – and what to look for before putting it back to work.

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What Does It Cost to Replace a Diesel Fuel Injector in 2026?

If your diesel engine is running rough, smoking, or losing power, a failing fuel injector could be the cause.

One of the first questions most people ask is: How much does it cost to replace a diesel fuel injector?

The answer depends on your engine, injector type, and how far the issue has progressed. Some injector problems are caught early. Others turn into much larger repairs.

Let’s break down what actually impacts the cost – and what you can expect in 2026.

Continue reading What Does It Cost to Replace a Diesel Fuel Injector in 2026?