MajorCommonEngine

Mitsubishi Pajero: 4M41 3.2L DI-D Common Rail Injector Seizure and Carbon Fouling

4M41 3.2L DI-D Common Rail Injector Seizure and Carbon Fouling is a common engine fault on the Mitsubishi Pajero on the 1999–2006 cars, and we rate it major. Putting it right costs $2,500 to $8,000 at New Zealand independent workshop rates. Below is what goes wrong, the symptoms to notice on a test drive, where to look, and what to ask the seller before you hand over any money. It is one of 39 documented faults on the Mitsubishi Pajero.

Vehicle: Mitsubishi Pajero
Engine: 4M41
Years: 1999–2006
Fuel: diesel
System: Engine

This page covers the Mitsubishi Pajero as a model. Some faults only affect particular engines or build years — enter a plate below to narrow the list to one car.

All Mitsubishi Pajero faults39 documented faults on this model

What you are looking at

What goes wrong

The common-rail 4M41 diesel fitted to Gen 3 Pajeros suffers from injector seizure caused by carbon and combustion deposits bonding the injector body to the cylinder head at high mileage. Removal of seized injectors can shear the injector body, requiring specialist extraction equipment and potentially damaging the head. Each replacement injector must be coded to the ECU. A full set of four injectors plus labour and coding represents one of the most expensive mechanical failures on this platform.

What you would notice

Rough or lumpy idle that varies with temperature
Diesel rattle or tap from one or more cylinders
Hard starting from cold
White or black smoke on acceleration
Increased fuel consumption without other explanation

How to check it

Where to look. Injectors mounted in the cylinder head, accessed from the top of the engine under the rocker cover area

Start the engine from cold and listen for injector rattle that settles as the engine warms — a rattle that persists suggests a failing injector.
Request fuel system and injector service history.
An injector balance test by a diesel specialist can identify a weak or dead injector without removal.
Check for any stored ECU fault codes relating to injector circuit.

Parts involved: Fuel rail, Fuel injector.

What it costs to put right

$2,500 to $8,000 at New Zealand independent workshop rates. That is for this job on its own, not for the car.

An estimate, in NZD, for the repair as normally carried out. What a specific car costs depends on which part has failed and what it damaged on the way — treat this as the floor for a negotiation, not a quote.

Ask the seller

“Have the injectors ever been removed, tested, or replaced?”
“What grade and brand of diesel has the vehicle used?”
“Are there any stored fault codes or check engine lights?”

Now check the Mitsubishi Pajero you are actually looking at

Everything above is true of the model, and it is free. What it does not tell you is whether THIS car has been looked after: its odometer history and whether the reading has ever gone backwards, whether there is still money owing on it, whether it has been reported stolen, how many owners it has had and what it is really worth today. That comes from the official records for that plate. Enter the plate for the free details, or get the full history and a market valuation from $13.49.

Not sure what you would be paying for? See what a full KickTyres check includes.

Where this comes from

The failure described above is documented in published sources — owner forums, technical service bulletins, recall notices and workshop write-ups — held in our fault database. The inspection instructions and the cost estimate are KickTyres’ own interpretation of them, and it is a starting point for an inspection rather than a manufacturer statement.

Mitsubishi Pajero buyer questions

Is 4m41 3.2l di-d common rail injector seizure and carbon fouling serious on a Mitsubishi Pajero?

We rate it major and common on the Mitsubishi Pajero. The common-rail 4M41 diesel fitted to Gen 3 Pajeros suffers from injector seizure caused by carbon and combustion deposits bonding the injector body to the cylinder head at high mileage. Removal of seized injectors can shear the injector body, requiring specialist extraction equipment and potentially damaging the head. Each replacement injector must be coded to the ECU. A full set of four injectors plus labour and coding represents one of the most expensive mechanical failures on this platform.

How much does it cost to fix on a Mitsubishi Pajero?

$2,500 to $8,000 at New Zealand independent workshop rates. That figure is for this job on its own. A car showing the symptoms on this page is usually worth either walking away from or negotiating down by at least the repair figure.

Which Mitsubishi Pajero years are affected?

Our research records this fault on the 1999–2006 Mitsubishi Pajero. Build dates move around, especially on imported cars, so treat the range as the years to look hardest at rather than a guarantee either way. The official records tell you the exact build and first registration date for the car in front of you.

How do I check for it before I buy?

Start the engine from cold and listen for injector rattle that settles as the engine warms — a rattle that persists suggests a failing injector. Request fuel system and injector service history. An injector balance test by a diesel specialist can identify a weak or dead injector without removal. Check for any stored ECU fault codes relating to injector circuit. Look here: Injectors mounted in the cylinder head, accessed from the top of the engine under the rocker cover area