Core charges are commonplace in the diesel engine industry, but surprisingly, many customers don’t know what they are. If you’re one of our many curious customers, we’ve compiled this handy guide on core charges. We recommend that anyone planning on buying replacement parts check it out!
Continue reading What is a Core Charge?Category: Blog – Ask the Diesel Engine Experts
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
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 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.
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
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 PartsHistory of Vehicle Emissions Regulations: From Smog Controls to Modern Diesel Standards
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 StandardsVGT 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?)Diesel Fuel Algae: What It Is, How to Treat It, and How to Prevent It
If your diesel engine keeps clogging fuel filters, losing power, stalling, or pulling dark sludge from the tank, you may hear someone say you have “diesel algae.”
That term is common, but it is not technically correct.
Diesel fuel algae is usually not algae at all. True algae needs sunlight to grow, and fuel tanks are dark environments. What people call diesel algae is usually microbial contamination made up of bacteria, fungi, yeasts, mold, and biofilm living in the fuel system.
This contamination is often called diesel bug.
The problem starts when water enters the fuel tank. Microbes live in the water and feed on hydrocarbons in the diesel fuel. Over time, they create dark, slimy sludge that can plug filters, restrict fuel flow, damage injectors, corrode tanks, and leave equipment stranded.
Continue reading Diesel Fuel Algae: What It Is, How to Treat It, and How to Prevent ItAutomatic vs Manual Transmissions in Diesel Trucks: What’s the Difference?
Diesel engines are known for low-RPM torque, strong pulling power, and durability under load.
Because of that, the transmission behind the engine matters.
A diesel transmission has to manage:
- High torque output
- Heavy loads
- Heat generation
- Gear changes under load
- Driver control
The biggest difference between automatic and manual transmissions is how power gets from the engine to the wheels and how gear changes are controlled.
For diesel trucks, there is also a third category that matters: automated manual transmissions.
Continue reading Automatic vs Manual Transmissions in Diesel Trucks: What’s the Difference?Why Flow-Matched Fuel Injectors Matter in Diesel Engines (And When They Actually Make a Difference)
When it comes to diesel engine performance, most people focus on major components: turbochargers, pistons, cylinder heads.
But one of the most overlooked factors in engine performance, efficiency, and longevity is fuel injector balance.
Specifically, how closely each injector matches the others in fuel delivery.
That’s where flow-matched fuel injectors come in.
Continue reading Why Flow-Matched Fuel Injectors Matter in Diesel Engines (And When They Actually Make a Difference)Most Common Engine Rebuild Kit Problems in Diesel Engines
A diesel engine rebuild kit can completely change the life of an engine — but only if everything is installed, measured, and matched correctly.
The reality is:
👉 Many engine rebuild failures are not caused by the rebuild kit itself.
They are caused by:
- Improper installation
- Incorrect measurements
- Poor machining
- Cooling system issues
- Lubrication problems
- Contamination left inside the engine
- Reusing damaged components
Even the highest-quality diesel engine rebuild kit can fail quickly if the root cause of the original failure was never corrected.
That is why successful diesel rebuilds depend on:
- Proper diagnostics
- Precision measurements
- Careful assembly
- Cleanliness
- Correct break-in procedures
A diesel engine rebuild is much more than simply “installing new parts.”
Continue reading Most Common Engine Rebuild Kit Problems in Diesel EnginesThe Complete Guide to Cummins Engine Rebuild Kits: Maximizing Performance and Value
When your Cummins diesel engine starts showing signs of wear, you face a critical decision: replace the entire engine or invest in a comprehensive engine rebuild. For fleet operators and owner-operators alike, Cummins engine rebuild kits represent the smart choice for restoring engine performance while maintaining cost control. These carefully engineered kits provide everything needed to bring your engine back to like-new specifications without the premium price of a complete replacement.
Continue reading The Complete Guide to Cummins Engine Rebuild Kits: Maximizing Performance and Value
