Category: Blog – All HHP Blog Articles

Keyword Search

Posted on by

How to Reduce Diesel Engine Fuel Consumption (What Actually Works)

Fuel is one of the biggest operating costs for trucks, equipment fleets, and diesel-powered businesses. And while fuel prices rise and fall, one thing never changes: wasted fuel is wasted money.

The good news? You don’t need pricey retrofit kits or major engine conversions to improve efficiency. Most fuel savings come from simple steps you can take today – and in many cases, it’s caused by worn internal components that your engine is already overdue to replace.

At Highway and Heavy Parts, we help customers improve reliability, uptime, and fuel efficiency every day through better engine parts and better maintenance decisions. Here’s how to reduce fuel cost fast.

1. Start With the Fuel System: Small Problems = Big Fuel Waste

Your diesel engine is only as efficient as the fuel system feeding it. When injectors, filters, or seals start to fail, your fuel burn climbs quickly.

Watch for these Common Fuel-Wasting Issues:

  • Worn or Dirty Fuel Injectors
  • Clogged Fuel Filters
  • Leaking Fuel Lines or O-Rings
  • Poor Atomization

Even minor injector wear can drop fuel economy by 2–5%, which adds up quickly across thousands of miles or engine hours. Highway and Heavy Parts carries high-quality fuel system components here, designed to restore proper spray patterns and combustion efficiency.

2. Fix Blow-By and Compression Loss Before It Gets Expensive

Worn internal engine components don’t just affect power – they kill fuel economy.

These Parts Directly Impact How Efficiently Your Engine Burns Fuel:

  • Piston Rings
  • Cylinder Liners
  • Main and Rod Bearings
  • Gaskets and Seals

When cylinder pressure drops or blow-by increases, the engine must burn more fuel to produce the same work. Many customers don’t notice this happening until they see a spike at the fuel pump.

3. Keep Your Airflow Clean and Boost Leaks Sealed

Your engine is an air pump – if airflow is restricted, fuel consumption goes up.

Be on the Lookout For:

  • Dirty Air Filters
  • Damaged Turbocharger Gaskets
  • Leaking Charge-Air Boots
  • Cracked Intercooler Piping

A turbocharger losing just a little boost pressure can cause an engine to over-fuel significantly.

4. Reduce Friction With Better-Quality Components

Every moving part inside your engine creates drag. As parts wear, friction increases. And when friction increases, the engine needs more fuel to overcome it.

Components that Influence Friction:

  • Bearings
  • Bushings
  • Camshaft Followers
  • Oil Pumps

Using high-quality internal components during maintenance and rebuilds helps keep friction losses low – which directly improves fuel economy.

Many customers choose HHP’s aftermarket bearings, gaskets, and rebuild components to restore factory-spec friction performance without paying OEM prices.

5. Keep Up With Preventive Maintenance (Your Wallet Will Thank You)

The easiest way to improve fuel economy is simply staying ahead of maintenance. A well-maintained diesel engine uses every drop of fuel efficiently.

Build a Simple Checklist:

  • Replace Fuel Filters on Time
  • Monitor Turbo Boost Pressure
  • Inspect Fuel Injectors Regularly
  • Watch for Oil Consumption or Blow-By
  • Change Air Filters Proactively
  • Check for Exhaust Leaks

A fleet that runs a consistent maintenance program can save thousands of dollars per truck each year.

6. Track Your Fuel Economy Before and After Repairs

Many operators never track MPG or gallons per hour – but this simple habit helps you spot declining efficiency before it becomes a major repair.

Track:

  • Baseline MPG Before Component Replacement
  • Fuel Economy After Injector or Gasket Updates
  • Load-Specific Fuel Consumption
  • Idle Time and PTO Time

If you’ve recently installed new internal components, bearings, injectors, or seals from Highway and Heavy Parts, tracking fuel use will show exactly how much your engine improved.

7. Don’t Buy the Cheapest Parts – Buy the Right Parts

The video below makes one point very clear: Cheap parts cost more in the long run.

Poorly Machined or Low-Grade Components:

  • Wear Out Faster
  • Reduce Engine Efficiency
  • Increase Downtime
  • Cause Premature Engine Failures
  • Waste Fuel Due to Poor Tolerances

Highway and Heavy Parts carries parts engineered for performance and longevity – helping keep engines efficient, reliable, and profitable.

How To Reduce Fuel Costs On Your Diesel Engine!

Final Takeaway: You Don’t Need Costly Upgrades to Save Fuel

Most Fuel Waste Comes From:

  • Minor Fuel System Issues
  • Normal Internal Engine Wear
  • Dirty Airflow Components
  • Turbocharger or Boost Leaks
  • Neglected Maintenance

By addressing these simple areas using quality parts, you can reclaim efficiency, power, and fuel savings instantly. For more information on diesel fuel and standards, check out the United States Environmental Protection Agency website here.

Guaranteed for fit and function, HHP parts have the right combination of quality and price with total support from our on-staff ASE-certified technicians. With specialized knowledge, quality products, fast shipping, and unbeatable customer service, HHP has you covered.

Call 844-304-7688 or visit highwayandheavyparts.com to place your order today.

From diagnosis through delivery, we’re Highway and Heavy Parts.

Posted on by

Diesel Engine Basics: The Main Parts of a Diesel Engine and What They Do

Diesel engines may look complicated from the outside, but most of their major systems work together toward one goal: turning fuel, air, compression, and heat into usable power.

Unlike gasoline engines, diesel engines do not use spark plugs to ignite the fuel. Instead, a diesel engine pulls in air, compresses that air until it becomes extremely hot, and then injects fuel into the cylinder. The heat from compression ignites the fuel, forcing the piston downward and turning the crankshaft.

That process is called compression ignition.

Modern diesel engines are more advanced than ever, but the basic systems remain the same. Whether you are working on a Caterpillar, Cummins, Detroit Diesel, International/Navistar, Paccar, Mack, Volvo, John Deere, Ford, Mercedes-Benz, Chevy/GMC, Dodge, or Perkins engine, the major parts all have specific jobs to do.

Diesel Engine Basics: A diesel engine needs air, fuel, compression, lubrication, and cooling to work properly. When one of those systems fails, performance, reliability, and engine life can all be affected.
Continue reading Diesel Engine Basics: The Main Parts of a Diesel Engine and What They Do
Posted on by

Perkins Engine Rebuild: Why the Crankshaft Won’t Turn After Assembly

You finish a Perkins engine rebuild, go to rotate the crankshaft. And it won’t move.

Or worse, it turns slightly and then binds.

This is one of the most frustrating problems after a rebuild, and it almost always comes down to clearance, alignment, or assembly issues.

If a crankshaft won’t turn freely after assembly, something is wrong. There is no “break-in” that will fix it.

Quick Answer: Why the Crankshaft Won’t Turn

  • Incorrect bearing clearances
  • Improper crankshaft machining
  • Main cap or rod cap misalignment
  • Thrust bearing installation issues
  • Debris or contamination during assembly
  • Incorrect torque sequence or values

Every one of these directly affects how the crankshaft rotates inside the block.

What “Normal” Should Feel Like

Quick takeaway: A properly assembled crankshaft should rotate smoothly with consistent resistance.

With:

  • Bearings installed
  • Caps torqued to spec
  • No pistons installed

You should be able to rotate the crankshaft by hand using a breaker bar. If you feel:

  • Tight spots
  • Binding
  • Uneven resistance

That indicates a mechanical issue: not normal assembly friction.

1. Incorrect Bearing Clearance (Most Common Cause)

Quick takeaway: Too little clearance will lock the crankshaft.

Diesel engines like Perkins rely on precise oil clearance between:

  • Crankshaft journals
  • Main and rod bearings

Typical oil clearance ranges for many Perkins engines:

  • ~0.0015″ to 0.0030″

If clearance is too tight:

  • Oil film cannot form
  • Metal-to-metal contact increases
  • Crankshaft binds or locks

This often happens when:

  • Bearings are mismatched
  • Journals are machined incorrectly
  • Clearances are not verified with plastigage or micrometers

2. Improper Crankshaft Machining

Crankshaft machining must be exact.

Common issues include:

  • Incorrect journal sizing
  • Out-of-round journals
  • Improper surface finish
  • Incorrect fillet radius after grinding

The fillet radius (the transition between journal and crank web) is critical.

If it is not properly finished:

  • Stress concentration increases
  • Bearing fit can be affected
  • Rotation can become restricted

In heavy-duty diesel applications, crankshafts are often:

  • Precision-ground
  • Sometimes shot-peened for durability

Crankshaft condition is just as important as machining accuracy. Learn more about what causes crankshaft damage in our guide on the four main causes of a bent diesel crankshaft: Bent Diesel Crankshaft Guide

3. Main Bearing Cap Misalignment

Quick takeaway: Main caps must be installed in the correct position and orientation.

Each main cap is:

  • Line-bored with the block
  • Matched to a specific position

If caps are:

  • Installed in the wrong location
  • Installed backwards
  • Torqued unevenly

This can:

  • Distort the crank bore
  • Pinch the crankshaft
  • Cause binding

Even slight misalignment can prevent rotation.

4. Thrust Bearing Installation Issues

The thrust bearing controls:

  • Crankshaft end play (forward/backward movement)

If installed incorrectly:

  • The crankshaft can bind when torqued

Common mistakes:

  • Thrust bearing installed backwards
  • Improper seating
  • End play not checked

Typical end play must be within spec—too tight and the crankshaft will not rotate freely.

5. Debris or Contamination During Assembly

Quick takeaway: Even small debris can lock a crankshaft.

After machining:

  • Metal shavings can remain in oil passages
  • Dirt or lint can contaminate surfaces

If debris gets between:

  • Bearing and journal
  • Bearing and cap

It can:

  • Reduce clearance
  • Create high spots
  • Cause immediate binding

This is why thorough cleaning after machining is critical.

6. Incorrect Torque Sequence or Values

Main caps and rod caps must be:

  • Torqued in sequence
  • Torqued to specification

If not:

  • The crankshaft bore can distort
  • Bearings can be unevenly loaded

This creates:

  • Tight spots during rotation
  • Inconsistent resistance

7. Rear Main Seal and Housing Issues (Perkins-Specific)

Some Perkins engines, such as the 4.108, use:

  • Rope-style rear main seals
  • Two-piece seal housings

If installed incorrectly:

  • The seal can drag on the crankshaft
  • Housing misalignment can create resistance

Common issues:

  • Seal trimmed incorrectly
  • Seal packed too tightly
  • Housing sealed improperly

This can make the crankshaft feel tight even if bearings are correct.

8. Connecting Rod Installation Problems

Once pistons and rods are installed, additional issues can appear:

  • Rod caps installed incorrectly
  • Bearing shells misaligned
  • Rods not properly sized

This can:

  • Add resistance
  • Cause binding at specific rotation points

How to Diagnose a Crankshaft That Won’t Turn

Quick takeaway: Isolate the problem step-by-step.

1. Remove Pistons and Rods

  • Check crank rotation with only main bearings installed

2. Check Each Main Cap Individually

  • Torque one cap at a time
  • Rotate crank after each step

3. Measure Bearing Clearance

  • Use plastigage or micrometers
  • Verify against spec

4. Check Crankshaft End Play

  • Verify thrust bearing installation
  • Measure with dial indicator

5. Inspect for Debris

  • Clean all surfaces thoroughly
  • Check oil passages

This Is a Precision Problem

We see this often:

The parts are new, but the system isn’t correct.

A crankshaft that won’t turn is not a defective part issue.
It’s almost always:

  • Machining
  • Measurement
  • Or assembly accuracy

Diesel engines require tight tolerances. Small errors create big problems.

Final Thoughts

If your Perkins engine crankshaft won’t turn after a rebuild, stop immediately.

Do not force it.

Binding is a sign that:

  • Clearances are incorrect
  • Components are misaligned
  • Or something was assembled improperly

Fixing the issue now prevents:

  • Bearing failure
  • Crankshaft damage
  • Complete engine failure

Browse our Perkins engine rebuild kits HERE

Or call 844-304-7688 to speak with a diesel expert.

From diagnosis through delivery, we’re Highway and Heavy Parts.

Posted on by

Why Your ECM Report May Not Be Enough To Order Diesel Engine Parts

Ordering diesel engine parts should be simple.

Find the engine information, look up the part, place the order, and get the truck back together.

But in the real world, engine identification can get complicated fast.

A customer may have one number from an ECM report, another number stamped on the engine block, another number on the valve cover data place, and still another number cast into a component. If these numbers do not match, it can lead to the wrong part being ordered – even when the customer believed they were using the right information.

This is why Engine Serial Number (ESN) Verification matters.

The ECM can be helpful, but it should not always be treated as the final authority. If the ECM has been replaced, reflashed, cloned, or programmed with information from another engine, the data it reports may not match the physical engine in the truck.

HHP Quick Takeaway

When ordering diesel engine parts, the safest approach is to verify the physical Engine Serial Number from the engine data plate or stamped engine block—not just the ECM report. ECMs can be replaced or programmed incorrectly, and using the wrong number can lead to incorrect parts, installation delays, and avoidable returns.
Continue reading Why Your ECM Report May Not Be Enough To Order Diesel Engine Parts
Posted on by

Detroit Gen 6 Engines: What the New DD13, DD15, and DD16 Mean for 2027–2028

Detroit recently unveiled its new Gen 6 heavy-duty engine lineup, including the:

  • DD13,
  • DD15,
  • and DD16,

with production beginning in January 2027 for the DD13 and DD15, followed by the DD16 in January 2028.

Continue reading Detroit Gen 6 Engines: What the New DD13, DD15, and DD16 Mean for 2027–2028
Posted on by

Diesel Injector Symptoms: How To Tell If Your EUI Injectors Are Failing

If you’re noticing common diesel injector symptoms like rough idle, smoke, or loss of power, there’s a good chance your fuel system is the problem.

And if you’re running an engine with Electronic Unit Injectors (EUIs), the symptoms can show up fast – and get expensive even faster.

Because with EUIs, you’re not just dealing with fuel delivery.

You’re dealing with timing, pressure, and combustion all at once.

If one injector starts to fail, it doesn’t stay isolated.

Continue reading Diesel Injector Symptoms: How To Tell If Your EUI Injectors Are Failing
Posted on by

What Diesel Techs Actually Look For Before Recommending Engine Parts

When a diesel engine comes in with a problem, experienced technicians don’t start by picking parts. Instead, they start by asking why the failure happened in the first place. However, not every failure is immediately obvious without proper inspection.

They start by asking:

What caused the failure in the first place?

Because replacing parts without understanding the root cause is one of the fastest ways to create repeat repairs.

This is the approach used by experienced diesel professionals at Highway and Heavy Parts – where real-world experience drives every recommendation.

Continue reading What Diesel Techs Actually Look For Before Recommending Engine Parts
Posted on by

When to Replace Fuel Injectors in a Caterpillar C15 Acert

Is your fuel efficiency down? Has the performance of your CAT C15 ACERT dropped?

Continue reading When to Replace Fuel Injectors in a Caterpillar C15 Acert
Posted on by

Detroit Diesel Series 60 Engine Highlight

Detroit Diesel Series 60 Diesel Engine

Introduction to the Detroit Diesel Series 60

The Detroit Diesel Series 60 remains one of the most iconic and reliable heavy-duty diesel engines ever manufactured. Introduced in 1987, the Series 60 revolutionized the trucking industry with its inline-six configuration, electronic controls, and impressive power output. Available in multiple displacements, the 12.7L and 14L variants became the workhorses of countless fleets across North America, powering everything from highway tractors to vocational trucks and buses.

Detroit Diesel Series 60 Diesel Engine

For over three decades, these engines have proven their durability on highways and job sites alike. Whether you’re maintaining a legacy fleet or rebuilding a classic Series 60, understanding the strengths, weaknesses, and maintenance requirements of these legendary powerplants is essential for maximizing performance and longevity.

Series 60 Engine Specifications and Configurations

The Detroit Diesel Series 60 came in two primary displacement options that became industry favorites, and the less popular 11.1L. The 12.7L Series 60 offered an excellent balance of power and efficiency, producing between 350 and 500 horsepower depending on the configuration. This displacement became the most popular choice for over-the-road applications where fuel economy and reliability were paramount.

The 14L Series 60 delivered even more muscle for demanding applications. With power ratings ranging from 425 to 575 horsepower, the 14-liter variant excelled in heavy-haul operations, mountainous terrain, and vocational applications requiring maximum torque. Both engines featured Detroit Diesel’s renowned Electronic Control Module (ECM) technology, which provided precise fuel delivery and diagnostic capabilities that were ahead of their time.

These inline-six cylinder engines utilized a four-stroke cycle design with overhead camshafts, unit fuel injectors, and robust cast-iron construction. The Series 60’s modular design made maintenance more accessible compared to previous generations, while its electronic architecture allowed for easier troubleshooting and performance tuning.

Advantages of the Detroit Diesel Series 60

Proven Reliability and Longevity

The Series 60’s reputation for durability is well-earned. With proper maintenance, these engines routinely achieve over one million miles of service. The robust engine block, quality internal components, and proven design contribute to exceptional longevity that keeps older trucks productive and profitable.

Parts Availability and Aftermarket Support

Series 60 turbocharger

One significant advantage of the Series 60 is the extensive parts availability. Companies like Highway and Heavy Parts maintain comprehensive inventories of Detroit Diesel engine components, including engine rebuild kits, fuel injectors, cylinder heads, and complete engine assemblies. This widespread parts support keeps maintenance costs manageable and downtime minimal.

Excellent Power-to-Weight Ratio

Compared to competitors, the Series 60 offers impressive horsepower in a relatively compact and lightweight package. This efficiency translates to better payload capacity and fuel economy, making it an economical choice for fleet operators.

Electronic Control Systems

The Series 60’s advanced electronics provide unprecedented control over engine parameters. The Detroit Diesel Electronic Control (DDEC) system allows technicians to quickly diagnose issues, adjust performance parameters, and monitor engine health through comprehensive data logging capabilities.

Strong Torque Characteristics

Both the 12.7L and 14L versions deliver flat torque curves with excellent low-end grunt. This characteristic made the Series 60 particularly well-suited for applications requiring strong pulling power and responsive throttle response under load.

Disadvantages and Common Issues

Fuel Economy Compared to Modern Engines

While efficient for their time, Series 60 engines cannot match the fuel economy of modern emissions-compliant powerplants. Newer engines with advanced injection systems, turbocharging technology, and aerodynamic improvements deliver significantly improved fuel efficiency, resulting in better miles per gallon.

Unit injector issues represent one of the most common maintenance concerns with Series 60 engines. Fuel injector failures can cause rough running, excessive smoke, poor fuel economy, and reduced power. Regular fuel injector maintenance and timely replacement are essential for optimal performance.

Oil Consumption Concerns

Some Series 60 engines, particularly higher-mileage units, can develop increased oil consumption. Worn valve guides, seals, and piston rings contribute to this issue, which may require cylinder head work or complete engine overhauls to resolve.

Overhead Adjustment Requirements

Unlike modern engines with hydraulic lifters, the Series 60 requires periodic overhead adjustments to maintain proper valve clearances. This maintenance requirement demands skilled technicians and adds to the total cost of ownership.

Emissions Limitations

Pre-2002 Series 60 engines lack the sophisticated emissions controls required by current regulations. This limitation restricts their use in certain jurisdictions and applications, though many operators appreciate the simplicity of pre-emissions designs.

Essential Parts for Series 60 Maintenance and Repair

Maintaining peak performance from your Detroit Diesel Series 60 requires quality replacement parts and regular service intervals. Highway and Heavy Parts offers a comprehensive selection of components specifically designed for the 12.7L and 14L Series 60 engines.

Engine Rebuild Kits for Complete Overhauls

DD60 Engine Rebuild Kit

When your Series 60 reaches high mileage or experiences significant wear, a complete engine rebuild kit provides everything needed for a comprehensive overhaul. Quality engine rebuild kits include pistons, rings, bearings, gaskets, seals, and other essential components. These kits restore your engine to like-new condition, extending service life by hundreds of thousands of miles while improving reliability and performance.

Fuel Injectors for Optimal Fuel Delivery

DD60 Fuel Injector

Electronic unit fuel injectors are critical to Series 60 performance. Fresh fuel injectors ensure proper fuel atomization, improve combustion efficiency, reduce emissions, and restore lost horsepower. Whether replacing failed fuel injectors or upgrading an entire set, quality fuel injectors from reputable suppliers prevent the rough running, smoke, and poor fuel economy associated with worn or failing units.

Cylinder Heads for Superior Performance

DD Series 60 Cylinder Head

Cylinder heads endure extreme temperatures and pressures, making them susceptible to cracking, valve seat wear, and gasket failures. Replacement cylinder heads—whether remanufactured or new—restore compression, eliminate coolant and oil leaks, and ensure proper valve seating. Many operators choose upgraded cylinder heads during engine rebuilds to improve durability and performance characteristics.

Maximizing Series 60 Engine Life

Proper maintenance practices dramatically extend Series 60 engine life. Regular oil changes using quality lubricants, timely fuel filter replacements, and attention to coolant system health prevent many common issues. Monitoring operating temperatures, addressing leaks promptly, and performing scheduled overhead adjustments keep these engines running strong.

Many operators implement oil analysis programs to detect wear metals and contamination before catastrophic failures occur. This proactive approach identifies developing problems early, allowing for planned maintenance rather than unexpected roadside breakdowns.

FAQs About the Detroit Diesel Series 60 Engine

series 60 engine

What is the difference between a 12.7L and a 14L Series 60?

The primary difference is displacement and power output. The 12.7-liter version typically produces 350 to 500 horsepower and is more fuel-efficient, making it ideal for highway applications. The 14-liter variant generates 425 to 575 horsepower with higher torque, better suited for heavy-haul and vocational work requiring maximum pulling power.

How often should Series 60 fuel injectors be replaced?

Fuel injector replacement intervals vary based on fuel quality, operating conditions, and maintenance practices. Most operators replace fuel injectors between 300,000 and 500,000 miles. However, monitor engine performance closely—excessive smoke, rough idle, or decreased fuel economy indicate fuel injector replacement may be sooner.

What are the signs that my Series 60 needs a rebuild?

Common indicators include excessive oil consumption, low compression, increased blow-by, persistent coolant leaks, abnormal engine noises, difficulty maintaining operating temperature, and significant power loss. Oil analysis showing elevated wear metals also suggests internal component deterioration requiring rebuild attention.

Can I upgrade my Series 60 engine performance?

Yes, Series 60 engines respond well to electronic tuning and turbocharger upgrades. However, any modifications should be performed by experienced professionals who understand the balance between increased performance and engine longevity. Excessive power increases can accelerate component wear.

Where can I find quality parts for Detroit Diesel Series 60 maintenance?

Highway and Heavy Parts (highwayandheavyparts.com) specializes in Detroit Diesel components, offering engine rebuild kits, fuel injectors, cylinder heads, and comprehensive engine parts inventories. Their extensive selection ensures you’ll find quality components for 11.1L, 12.7L, and 14L Series 60 engines, supporting everything from routine maintenance to complete overhauls.

Posted on by

DuraWRX DEF Headers: Why One Small Component Can Shut Down an Entire Truck

Modern diesel engines are cleaner and more efficient than ever before, but they’ve also become far more dependent on electronics. Today, a relatively small component inside your Diesel Exhaust Fluid (DEF) system can take an otherwise healthy truck completely out of service.

One of the most common examples is the DEF header assembly.

If the DEF header fails—or if the Engine Control Module (ECM) receives inaccurate information from it—the truck may begin a series of emissions derates that reduce engine power and vehicle speed until repairs are made.

For fleets, owner-operators, and repair shops, that means lost productivity, missed deliveries, and unnecessary downtime.

That’s why Highway and Heavy Parts now offers DuraWRX™ DEF Management Solutions by Shaw Development—premium DEF headers and sensors engineered specifically for demanding commercial diesel applications and backed by an industry-leading 2-year warranty.

DuraWRX DEF Header Assembly

DuraWRX DEF Header Assembly by Shaw Development

What Does a DEF Header Actually Do?

Many people think the DEF tank simply stores fluid.

In reality, the DEF header is one of the most important components inside the entire Selective Catalytic Reduction (SCR) system.

A modern DEF header continuously monitors:

  • DEF fluid level
  • DEF temperature
  • DEF quality
  • Heater operation
  • Fluid pickup
  • Electrical communication with the ECM
What the DEF Header Monitors
DEF Level
Measures how much fluid is in the tank.		 DEF Temperature
Helps manage cold-weather operation and thawing.
DEF Quality
Verifies proper fluid concentration.		 Heating Function
Supports DEF flow during freezing conditions.
Fluid Pickup
Draws DEF from the tank for system use.		 ECM Communication
Sends critical data to the engine control system.

The ECM depends on this information to determine whether the emissions system is functioning correctly.

If any of that information becomes inaccurate—or communication is lost—the ECM cannot verify emissions compliance. Instead of assuming everything is fine, it begins protecting the system by progressively limiting engine performance.

New to DEF Systems?

Before diagnosing a DEF header, it helps to understand how DEF works and what happens when diesel engines sit too long. These guides explain the basics behind DEF fluid, SCR systems, crystallization, fuel aging, and emissions-related downtime.
DEF Basics
Learn what Diesel Exhaust Fluid does, how SCR systems use it, and what happens if DEF runs out.
Read the DEF guide
Sitting Too Long
Learn how fuel degradation, DEF crystallization, moisture, and internal engine issues can show up after a truck sits.
Read the diesel storage guide

Why DEF Header Failures Cause So Much Downtime

Unlike many engine failures, DEF system problems often have nothing to do with the mechanical health of the engine itself.

Your truck may continue running perfectly while a sensor begins reporting inaccurate information.

Eventually, the ECM responds by initiating an emissions derate.

This usually progresses through several stages:

Typical DEF Failure Progression
1
Warning Light		 2
Fault Codes		 3
Engine Derate		 4
Reduced Speed		 5
Truck Down

The actual replacement component may represent only a fraction of the repair cost. The real expense often comes from technician labor, missed deliveries, idle equipment, and lost revenue.

Why DEF Headers Fail

DEF components operate in one of the harshest environments on the truck.

They’re constantly exposed to:

  • Daily freeze/thaw cycles
  • Road vibration
  • Moisture
  • Road salt
  • Diesel exhaust heat
  • DEF crystallization

Over time, these conditions can affect electrical connectors, heating elements, sensor calibration, seals, and internal electronics.

Some of the most common causes include:

  • DEF crystallization around sensors
  • Moisture intrusion
  • Connector corrosion
  • Wiring fatigue
  • Thermal cycling
  • Internal electronic failures

Diagnosing the Problem Correctly

Replacing the first component mentioned by a fault code isn’t always the right repair.

A proper diagnosis should include:

  1. Retrieve active and stored fault codes.
  2. Inspect DEF fluid quality and contamination.
  3. Examine the tank for crystallization or debris.
  4. Verify wiring, connectors, power, and grounds.
  5. Confirm communication between the ECM and DEF components.
  6. Install the correct replacement component.
  7. Clear codes and validate system operation.

This approach helps prevent unnecessary parts replacement and repeat repairs.

Why Choose DuraWRX?

Highway and Heavy Parts partners with Shaw Development, one of the industry’s leading manufacturers of DEF management systems, to provide premium aftermarket solutions for commercial diesel engines.

DuraWRX components are engineered to meet or exceed OE specifications while helping fleets reduce downtime and improve long-term reliability.

Features include:

  • OE-style fit and connectors
  • Precision-calibrated sensors
  • Corrosion-resistant materials
  • Heavy-duty construction
  • Commercial diesel applications
  • Industry-leading 2-year warranty
Why Shops Choose DuraWRX
OE-Style Fit
Designed for straightforward replacement.		 Commercial-Duty Design
Built for demanding diesel applications.
Sensor Accuracy
Supports reliable DEF system readings.		 Corrosion Resistance
Helps withstand moisture and road conditions.
Technical Support
Backed by HHP application help.		 2-Year Warranty
Provides added confidence in the repair.

Available DuraWRX Solutions

Highway and Heavy Parts offers a growing lineup of DuraWRX DEF management components, including:

  • DEF Header Assemblies
  • DEF Quality Sensors
  • DEF Heating Components
  • OE-Style Replacement DEF System Components

Whether you’re repairing a single truck or maintaining an entire fleet, our ASE Certified Technicians can help verify the correct application before you order.

Need Help Diagnosing a DEF System Problem?

Modern emissions systems have become one of the leading causes of unexpected diesel truck downtime—but many repairs can be completed correctly the first time with proper diagnostics and quality replacement components.

Highway and Heavy Parts combines premium DuraWRX DEF management solutions with experienced ASE Certified Technical Support to help repair shops and fleet operators minimize downtime and restore dependable operation.

Call 844-304-7688 or visit highwayandheavyparts.com to find the right DuraWRX DEF components for your application.

From diagnosis through delivery, we’re Highway and Heavy Parts.

Posted on by

History of Vehicle Emissions Regulations: From Smog Controls to Modern Diesel Standards

EPA diesel emissions standards timeline chart showing major regulations from 1970 to 2027 including Clean Air Act, ULSD, Tier 4, and NOx rules

Vehicle emissions regulations did not happen all at once.

They developed over decades as engineers, regulators, and manufacturers responded to air quality problems caused by hydrocarbons, carbon monoxide, nitrogen oxides, particulate matter, and later greenhouse gas emissions.

For diesel engines, the biggest changes came when regulations began focusing more heavily on particulate matter, NOx, fuel sulfur levels, and aftertreatment systems.

Continue reading History of Vehicle Emissions Regulations: From Smog Controls to Modern Diesel Standards
Posted on by

VGT Turbo Advantages (What Makes Variable Geometry Turbos Better?)

One of the biggest advantages of a Variable Geometry Turbo (VGT) isn’t just efficiency – it’s how it controls airflow at low engine speeds.

Because of this, VGT turbos can improve performance across a wider RPM range.

However, when that system stops working correctly, the engine feels completely different – and performance drops fast.

Continue reading VGT Turbo Advantages (What Makes Variable Geometry Turbos Better?)