MajorCommonFluid Leaks

Mitsubishi Challenger: 4M40 2.8D Injection Pump External Seal Failure

4M40 2.8D Injection Pump External Seal Failure is a common fluid leaks fault on the Mitsubishi Challenger on the 1999–2009 cars, and we rate it major. Putting it right costs $600 to $2,200 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 12 documented faults on the Mitsubishi Challenger.

Vehicle: Mitsubishi Challenger
Engine: 4M40
Years: 1999–2009
Fuel: diesel
System: Fluid Leaks

This page covers the Mitsubishi Challenger 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 Challenger faults12 documented faults on this model

What you are looking at

No photograph available

We do not hold a verified photograph of the High-pressure fuel pump yet. We would rather show none than show a picture of a different part.

What goes wrong

The Bosch-type injection pump fitted to the 4M40 2.8-litre diesel in K96W Challengers develops external seal and o-ring failures with age, allowing diesel fuel and pump lubricant to leak from the pump body and mounting area. This is a widely documented fault on 4M40-powered vehicles (also shared with Pajero) and is progressive — a minor seep can become a significant leak if ignored. Fuel contact with hot exhaust components is a fire risk.

What you would notice

Diesel or oil smell in engine bay when hot
Visible wet staining or drips from injection pump body
Black oily residue accumulation around pump base
Potential smoke from engine bay if fuel contacts exhaust

How to check it

Where to look. Injection pump, front-left area of engine

With engine warm, inspect the injection pump body carefully with a torch for any wet oil or fuel film. Check the mounting flange, drive seal at the front, and all banjo bolt joints. Run a clean cloth around the pump base and check for contamination. Significant staining indicates a long-standing leak.

Parts involved: High-pressure fuel pump.

What it costs to put right

$600 to $2,200 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

“Has the injection pump been reconditioned or had seals replaced?”
“Is there any diesel or oil smell from the engine bay?”
“When was the last major engine bay service?”

Now check the Mitsubishi Challenger 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 Challenger buyer questions

Is 4m40 2.8d injection pump external seal failure serious on a Mitsubishi Challenger?

We rate it major and common on the Mitsubishi Challenger. The Bosch-type injection pump fitted to the 4M40 2.8-litre diesel in K96W Challengers develops external seal and o-ring failures with age, allowing diesel fuel and pump lubricant to leak from the pump body and mounting area. This is a widely documented fault on 4M40-powered vehicles (also shared with Pajero) and is progressive — a minor seep can become a significant leak if ignored. Fuel contact with hot exhaust components is a fire risk.

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

$600 to $2,200 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 Challenger years are affected?

Our research records this fault on the 1999–2009 Mitsubishi Challenger. 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.