Signs It’s Time for a New Turbocharger

What Does a Turbocharger Do?

A turbocharger is a forced induction device that compresses the air entering your engine. This allows more oxygen to reach the combustion chamber, significantly increasing power output without enlarging the engine. In diesel applications, turbos also contribute to better fuel economy and cleaner emissions.

The system consists of two main sections:

• Turbine side: Exhaust gases spin a turbine, extracting energy from the engine’s waste.
• Compressor side: This turbine drives a compressor that forces additional air into the engine’s intake.

When working properly, your turbo should provide smooth acceleration, enhanced towing capacity, and fuel efficiency. When it’s failing, however, you’ll know it—and not in a good way.

Loss of Power and Acceleration

A noticeable reduction in horsepower or sluggish acceleration is often the first and most telling symptom. Turbochargers are designed to increase power by forcing more air into the engine. If your engine feels weaker—especially under load or during a climb—your turbo may no longer be creating the necessary boost pressure.

This may show up as:

• Struggling to haul loads that were previously manageable
• Slow throttle response
• An inability to maintain highway speeds on inclines

These issues can be caused by a cracked compressor housing, worn internal bearings, or a failing actuator.

Excessive Exhaust Smoke

Another dead giveaway? Smoke. Lots of it.

A healthy diesel emits minimal visible exhaust under load. A failing turbo, on the other hand, may allow engine oil to seep into the exhaust system, creating thick, blue or grey smoke. This isn’t just bad for the environment—it’s a serious red flag for internal turbo failure.

Types of smoke and what they indicate:

• Blue smoke: Oil is burning—commonly due to internal turbo seal failure.
• Black smoke: Improper air-fuel ratios—possibly from lack of boost.
• White smoke: Rare in turbo issues, but may still indicate a cracked housing or coolant entering the system.

Unusual Noises from the Turbo

Turbos should hum—not howl.

If you hear a high-pitched whining, grinding, or siren-like sound coming from the engine bay, you’re likely dealing with worn bearings or contact between the compressor wheel and the housing.

Common sounds include:

• Whining: Often due to damaged bearings.
• Rattling or clanking: Indication of foreign object damage or broken internal components.
• Siren-like wail: The hallmark of a turbo on its last legs.

Ignoring these sounds can result in total failure, where blades disintegrate and contaminate the engine.

Check Engine Light and Fault Codes

Modern diesel engines are equipped with sensors to monitor boost pressure, air-fuel ratios, and exhaust gas temperatures. When the turbo fails to perform within expected parameters, the ECM (Engine Control Module) will trigger a fault code and illuminate the check engine light.

Some of the most common codes related to turbo issues include:

• P0299: Turbocharger underboost
• P0234: Turbocharger overboost
• P2262: Turbo boost pressure not detected

Although these codes don’t always point directly to turbo failure, they’re strong indicators that the system needs immediate inspection.

Oil Leaks and Consumption

Turbochargers rely on engine oil for lubrication and cooling. When seals within the unit fail, oil can leak externally (visible around the turbo housing) or internally into the intake or exhaust system.

Symptoms of oil-related turbo issues include:

• Visible oil around the turbocharger
• Increased oil consumption without external leaks
• Oil fouling in the intercooler or intake piping

Left unchecked, this can lead to engine damage from lack of lubrication or oil contamination.

Excessive Boost Lag

Boost lag refers to the delay between stepping on the accelerator and the turbo delivering additional power. While some lag is inherent in large turbo systems, a sudden or worsening delay could point to:

• Wastegate actuator malfunction
• Sticky or seized variable geometry vanes
• Clogged air filters or intercooler issues

A slow-spooling turbo isn’t just inconvenient—it’s inefficient and potentially dangerous when merging or passing on the highway.

Visible Damage or Shaft Play

When in doubt, a hands-on inspection can confirm suspicions. During scheduled maintenance, a technician can remove intake piping and manually inspect the compressor wheel. If there’s excessive shaft play—either axial (in and out) or radial (side to side)—it means the internal bearings are worn.

Excessive shaft play often results in:

• Blades contacting the housing
• Imbalance and vibration
• Imminent failure

In such cases, immediate replacement is strongly advised.

Increased Exhaust Temperatures (EGTs)

Turbochargers play a critical role in controlling EGTs. A failing turbo, particularly one that’s not providing sufficient airflow, causes incomplete combustion—raising exhaust temperatures. Elevated EGTs can lead to damage in the exhaust manifold, DPF system, and even the pistons and valves.

Signs of high EGTs:

• Dashboard warning lights
• EGT gauge reading above safe operating range (1,250°F+)
• Exhaust components showing signs of heat damage

Monitoring EGTs regularly can help catch turbo issues early.

Stay Ahead of Turbo Trouble

If your turbocharger is on its way out, the signs aren’t subtle: power loss, excessive smoke, strange noises, and oil leaks all scream trouble. Catching these symptoms early can save your engine from further damage and keep your truck performing at peak levels.

Need help diagnosing or replacing your turbocharger in Des Moines, IA? Kustom Truck & Tire is just a call away.