Skip to content
KickTyres
MajorCommonCooling

Mitsubishi L300: Cooling-system corrosion and overheating (head-gasket risk)

Cooling-system corrosion and overheating (head-gasket risk) is a common cooling fault on the Mitsubishi L300 on the 2000–2013 cars, and we rate it major. Putting it right costs $400 to $3,500 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 6 documented faults on the Mitsubishi L300.

Vehicle
Mitsubishi L300
Years
2000–2013
Fuel
petrol
System
Cooling

This page covers the Mitsubishi L300 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 L300 faults6 documented faults on this model

What you are looking at

A removed multi-layer steel head gasket held up, showing staining around the cylinder bore.Example of the part — not this vehicle

A used multi-layer head gasket. Discolouration between a cylinder and a water gallery is the tell.

John Furman · CC BY-SA 3.0 · Wikimedia Commons

What goes wrong

The L300/Express builds up internal scale and rust that blocks the radiator and causes overheating, which is worse on hills or when loaded because the cab-over layout gives the engine marginal cooling. Owners describe flushing several hundred grams of rust out of the system — clear-looking coolant does not mean a clean system. Sustained overheating readily blows the head gasket on this engine, turning a cheap flush into a big job.

What you would notice

  • Temperature climbs on hills or under load
  • Coolant loss
  • Heater underperforms
  • Brown or rusty coolant

How to check it

Where to look. Radiator, thermostat, water pump and cylinder head

  1. Check the coolant colour and condition and look into the radiator for blockage.

  2. Watch the temperature gauge on a loaded or uphill test drive.

  3. Check the oil filler cap for a mayonnaise-like emulsion that suggests head-gasket trouble.

Parts involved: Head gasket, Body corrosion.

What it costs to put right

$400 to $3,500 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

  • “Does it run hot when loaded or going uphill?”
  • “When was the radiator and coolant last serviced?”
  • “Has it ever had head-gasket work?”

Now check the Mitsubishi L300 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 L300 buyer questions

Is cooling-system corrosion and overheating (head-gasket risk) serious on a Mitsubishi L300?

We rate it major and common on the Mitsubishi L300. The L300/Express builds up internal scale and rust that blocks the radiator and causes overheating, which is worse on hills or when loaded because the cab-over layout gives the engine marginal cooling. Owners describe flushing several hundred grams of rust out of the system — clear-looking coolant does not mean a clean system. Sustained overheating readily blows the head gasket on this engine, turning a cheap flush into a big job.

How much does it cost to fix on a Mitsubishi L300?

$400 to $3,500 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 L300 years are affected?

Our research records this fault on the 2000–2013 Mitsubishi L300. 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?

Check the coolant colour and condition and look into the radiator for blockage. Watch the temperature gauge on a loaded or uphill test drive. Check the oil filler cap for a mayonnaise-like emulsion that suggests head-gasket trouble. Look here: Radiator, thermostat, water pump and cylinder head