Variable Geometry Turbochargers (VGTs) are designed to adjust airflow dynamically—but when they fail, one issue shows up more than any other:
Sticking vanes. If the vanes can’t move, the turbo can’t control boost properly.
And that leads to:
The challenge is this:
Not every VGT problem is actually a bad turbo.
Continue reading Why Diesel VGT Turbo Vanes Stick (And How to Tell If It’s the Turbo or the Actuator)Two diesel truck owners experience the exact same engine failure.
Both need a cylinder head replacement. Both receive nearly identical repair estimates.
Yet one owner approves a complete engine overhaul, while the other replaces only the failed components and gets back on the road.
Who made the right decision? Surprisingly… They both did.
One plans to keep the truck for another 500,000 miles. The other plans to sell it within the next year.
The engines are identical. The failures are identical.
The repair recommendations aren’t.
Because the best diesel truck repair isn’t determined by the engine: It’s determined by the owner.
How you use your truck, how much downtime you can tolerate, how long you plan to keep it, and what you expect from the repair all play a major role in deciding what the “right” repair actually looks like.
At Highway & Heavy Parts, these are some of the first questions our ASE Certified Technicians ask before recommending replacement parts. Understanding your ownership style helps ensure you’re investing in the repair that makes the most sense—not simply the cheapest or the most expensive option.
A Caterpillar C15 ACERT inframe rebuild should restore engine performance – not lead to another failure 50,000 miles later.
But that’s exactly what happens when critical measurements, tolerances, and supporting components are overlooked during the rebuild process.
Most early failures aren’t caused by the rebuild kit itself – they’re caused by what wasn’t checked before installation.
Continue reading Why Some Caterpillar C15 ACERT Inframe Rebuilds Fail Early (And How to Prevent It)
A Variable Geometry Turbocharger (VGT) does more than create boost.
It actively controls airflow, exhaust energy, and turbo speed across different engine conditions.
When a VGT system starts to fail, the issue is not just loss of power – it affects:
Understanding how a VGT works – and how it fails – is key to diagnosing problems correctly.
Continue reading VGT Turbo Problems and Symptoms: How Variable Geometry Failures Affect Boost, Heat, and Engine Performance
The crankshaft is essentially the backbone of your truck’s engine. It keeps the engine moving and is vital to the overall health of your rig. When this critical component begins to fail in a Cummins ISX, it can quickly lead to severe mechanical damage and costly downtime. Recognizing the early warning signs of a worn or damaged crankshaft is essential to minimizing negative impacts to your revenue and keeping your truck out of the service bay.
Continue reading Diagnosing a Bad Cummins ISX Crankshaft: Symptoms and Replacement
On a Cummins N14, fuel injectors are one of the most critical components controlling engine performance.
They don’t just deliver fuel – they control timing, atomization, and combustion efficiency.
And when they start to fail, the issue doesn’t stay isolated to one cylinder. It begins to affect engine balance, temperature, and long-term durability.
Continue reading Cummins N14 Fuel Injectors: How They Fail, What It Affects, and When to Replace Them
An inframe rebuild on a Cummins ISX 870 or ISX 871 is supposed to bring your engine back to life.
But for a lot of operators, that’s not what happens.
Instead, they run into problems almost immediately:
The issue usually isn’t the rebuild itself.
It’s what happens during – and right after – the rebuild.
Continue reading Cummins ISX 870 Inframe Rebuild Problems: Why Engines Fail After a Rebuild
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
Fuel economy in a diesel engine isn’t just about driving habits – it’s controlled by combustion efficiency, fuel delivery accuracy, air management, and mechanical condition.
If one of those systems is off – even slightly – you’re burning more fuel than you should.
This guide breaks down five technical areas that directly impact fuel economy, and what’s actually happening inside the engine when they’re not right.
Continue reading 5 Technical Ways to Improve Diesel Engine Fuel Economy (Without Guessing)
Diesel fuel injectors do more than deliver fuel.
They control injection timing, atomization, pressure, and combustion efficiency.
When an injector begins to fail, the issue is rarely just “bad fuel delivery.”
It is usually a breakdown in one of three critical areas:
Understanding these failure modes is the key to diagnosing problems correctly – and avoiding repeat failures.
Continue reading Diesel Fuel Injector Failure Explained: Internal Leakage, Timing Loss, and Combustion Imbalance
When a turbocharger fails, the damage is often concentrated in one place:
The center housing rotating assembly (CHRA).
This is the core of the turbocharger – and in many cases, replacing it is the most efficient way to restore performance.
Continue reading Turbocharger Cartridges (CHRA): How Jrone Turbo Cores Restore Performance Without Replacing the Full Turbo
If you’re hearing noise when engaging the clutch, don’t ignore it.
What might seem like a minor issue – grinding, chatter, or a harsh engagement – can point to mechanical or hydraulic problems that will only get worse over time.
On heavy-duty diesel applications, clutch engagement issues typically fall into three categories:
Understanding the difference is critical – because each one leads to very different failure paths.
Continue reading Diesel Engine Noise During Clutch Engagement: Diagnosing Drag, Slip, and Hydraulic FailureView self help and informational diesel engine videos in Highway and Heavy Parts extensive video library.
