Mitsubishi TD04 Turbocharger: Applications, Specs & Replacement Guide

The Mitsubishi TD04 Turbocharger is one of the most widely used small-frame turbos ever built, showing up on everything from diesel pickups and SUVs to marine and industrial engines for the better part of four decades. If you turn wrenches for a living, you have almost certainly held one in your hands. At PT Turbo, where we have been rebuilding and supplying turbochargers since 1978, the TD04 remains a steady mover because it is compact, reliable, and used across a huge range of applications.

This guide covers what the TD04 family actually is, where it lives, the specs that matter, how to spot a failing unit, and what to consider when you replace or rebuild one.

What Is the Mitsubishi TD04 Turbocharger?

The TD04 is part of Mitsubishi Heavy Industries’ TD series of turbochargers, sitting between the smaller TD03 and the larger TD05 and TD06 frames. It uses a journal-bearing center housing rotating assembly (CHRA) and is available in wastegated, non-wastegated, and later variable-geometry configurations depending on the application.

What makes the TD04 so popular is its flexibility. The same basic frame supports a wide range of compressor and turbine wheel trims, letting manufacturers tune the exact same casting for a small 1.6L diesel or a 2.5L industrial engine. Common designations you will see stamped on the compressor housing include TD04L, TD04HL, and TD04-13T through TD04-19T, with the number referring to the compressor wheel size.

If you want a refresher on how turbos work in general, the turbocharger overview on Wikipedia is a solid technical starting point.

TD04 Applications: Where You Will Find It

The TD04 has one of the broadest application lists of any turbo in the Mitsubishi catalog. It has been fitted to passenger vehicles, light trucks, marine engines, and stationary industrial power units. Below is a representative sample of where the TD04 and its close relatives show up.

• Mitsubishi: Pajero/Montero, L200/Triton, Delica (4M40, 4M41 diesel engines)
• Subaru: Legacy, Forester, Impreza WRX (petrol TD04L variants)
• Volvo: 850, S70, V70, 940 turbo (TD04HL variants)
• Hyundai/Kia: various CRDi diesel platforms
• Marine and industrial: small Yanmar, Mitsubishi, and Isuzu diesel gensets and propulsion engines
• Construction and ag: compact excavators, skid steers, and utility engines in the 2.0L to 3.0L range

Because the TD04 spans gasoline and diesel, always verify the exact part number and wheel trim before ordering. A TD04L off a Subaru is not interchangeable with a TD04HL off a Volvo even though the frame name is the same. If you are cross-referencing a hard-to-find number, our team can help you match it correctly, just contact PT Turbo with your casting numbers.

Mitsubishi TD04 Turbocharger Specifications

Exact specs vary by variant, but the TD04 family shares a common architecture. Here are the typical ranges you can expect across the platform.

Specification	Typical TD04 Range
Compressor wheel inducer	Approx. 36 to 50 mm depending on trim
Turbine wheel	Approx. 41 to 47 mm
Bearing system	Journal (floating) bearing
Wastegate type	Internal, pneumatic actuator controlled
Typical airflow	Up to roughly 35 to 40 lb/min on larger trims
Realistic power support	Roughly 200 to 280 hp depending on variant
Cooling	Oil-cooled, some variants water-cooled

The larger TD04-19T and TD04HL-20T trims are popular in the performance world for exactly this reason: they bolt into a compact package but flow enough air to support meaningful power gains without lag. On the diesel side, the wastegated TD04 on the 4M40 and 4M41 engines is prized for its durability and quick spool.

The Role of the Pneumatic Actuator

Most wastegated TD04 and TD03 units rely on a pneumatic actuator to regulate boost. The actuator uses a spring-loaded diaphragm that opens the wastegate flap once boost pressure hits the set threshold, bleeding off exhaust gas to prevent overboost. When this actuator fails or leaks, you get overboost codes, boost creep, or inconsistent power.

These actuators are a common wear item and are far cheaper to replace than the whole turbo. Always confirm the calibration and rod length against your original before installing.

Symptoms of a Failing TD04 Turbocharger

The TD04 is durable, but no turbo lasts forever. Oil starvation, contaminated oil, foreign object damage, and worn actuators are the usual culprits. Catch problems early and you often save the CHRA. Ignore them and you risk taking out the engine.

Symptom	Likely Cause	Severity
Blue/gray exhaust smoke	Failing shaft seals, oil in exhaust	Moderate
Whining or grinding noise	Worn bearings, shaft play	High
Loss of boost / low power	Leaking actuator, cracked hose, worn wheels	Moderate
Overboost code / boost creep	Stuck or failed pneumatic actuator	Moderate
Oil leaking from turbo	Failed seals, blocked drain, high crankcase pressure	High
Excessive shaft play (visible)	Worn thrust or journal bearings	Critical

A quick field check: with the engine off and cool, pull the intake pipe and wiggle the compressor wheel. Slight rotational play is normal. Any wheel-to-housing contact or noticeable in-and-out (axial) movement means the bearings are gone and the unit needs a rebuild or replacement.

Replacing vs. Rebuilding Your Mitsubishi TD04 Turbocharger

When a TD04 fails, you have three practical paths: install a brand-new unit, fit a remanufactured unit, or rebuild the one you have. The right call depends on the condition of your core, your budget, and how fast you need the vehicle back in service.

Option	Typical Cost Range	Best For
New OEM turbo	$$$ (highest)	Late-model warranty work, no core available
Remanufactured turbo	$$ (mid)	Best value, most applications, fast turnaround
Rebuild your core	$ to $$ (lowest if core is good)	Original-fitment purists, rare part numbers
Actuator/seal repair only	$ (lowest)	Boost control issues with a healthy CHRA

For most owner-operators and fleets, a quality reman unit hits the sweet spot. Every turbo in our remanufactured turbochargers catalog is disassembled, cleaned, inspected, fitted with new bearings and seals, and balanced to OEM tolerances. That means you get near-new reliability at a fraction of the dealer price.

If your core is still sound and you want it rebuilt to spec, our turbocharger rebuild service handles TD04 units regularly. And if you just need parts, you can shop all turbos and components directly.

Installation Tips for the Mitsubishi TD04 Turbocharger

Turbos rarely fail for no reason. Before you bolt on a replacement, find out why the old one died or you will be doing the job twice.

• Flush the oil feed line and confirm strong, clean oil flow before startup.

• Replace the oil drain gasket and verify the drain is clear so oil cannot back up into the center housing.
• Change the engine oil and filter, and inspect the air filter and intake tract for any debris that could get drawn into the compressor wheel.
• Prime the CHRA with clean oil by hand before fitting, then crank with the fuel shut off until oil pressure builds.
• Check the actuator rod length and preload against the old unit so your boost control stays on spec.
• At first start, idle the engine for several minutes to let the bearings load up gradually rather than revving it right away.

Skipping these steps is the fastest way to kill a fresh turbo. The overwhelming majority of premature failures we see on returned units trace back to oil supply problems or ingested debris, not a bad part. Spend the extra half hour on the setup and a properly fitted TD04 will give you years of dependable service.

Frequently Asked Questions

What engines use the Mitsubishi TD04 turbocharger?

The TD04 is found on a wide range of diesel pickups, SUVs, and marine and industrial engines. Its versatility has made it a popular small-frame turbo for decades.

How do I know if my TD04 turbocharger needs replacement?

Common signs include excessive shaft play, oil leaks, whining noises, and reduced boost or power. If you notice these symptoms, it may be time for a rebuild or replacement.

Can the Mitsubishi TD04 turbocharger be rebuilt?

Yes, the TD04 is commonly rebuilt with new bearings, seals, and balanced components. Rebuilding is often more cost-effective than buying a brand-new unit.