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Top issues
18 known problems · 6 high
high
Rust - rear quarters, tailgate, windscreen surround, chassis
All engines
high
Overheating from aged cooling systems
All engines
high
Timing belt failure (interference engine)
5 of 6 engines
At this odometer
See which of this car's known problems are due at that mileage, which should already have been dealt with, and what's coming up.
Generations
Best and worst years for the Mitsubishi Pajero →
Before: None (first dedicated Mitsubishi 4WD wagon)
After: Pajero NM-NX (3rd gen, 2000-2006 onwards)
Price (AUD)
$3k-$15k
Body styles
3-door SWB wagon, 5-door LWB wagon
Drivetrain
Part-time 4WD (dual-range) - 1st gen NA-NG, Super Select 4WD / SS4 full-time-capable (dual-range, 2H/4H/4HLc/4LLc) - 2nd gen NH-NL
Origin
Japan
Built in
Japan
Overview
The Pajero that built Mitsubishi's 4WD reputation, sold across two distinct generations. The first generation (NA-NG, 1983-1991) is a classic leaf/coil ladder-frame, part-time dual-range 4WD with manual free-wheeling hubs - launched with the 2.6L 4G54 petrol and 2.3L 4D55 turbo-diesel, later gaining the 2.5L 4D56 diesel and, from the NF in 1988, the 3.0L 6G72 V6. The second generation (NH 1991 through NL to 2000) is a much more sophisticated thing: coil-sprung, more car-like, and the first 4WD with Super Select (SS4) - a part-time/full-time selectable transfer case that allows safe full-time 4WD on bitumen plus locked 4H/4L for off-road. Second-gen engines were the 2.5L 4D56 turbo-diesel, the chain-timed 2.8L 4M40 turbo-diesel (from 1993, the diesel to have), the 3.0L 6G72 V6 and the 3.5L 6G74 V6 (later GDI). These are now old, cheap vehicles: capable and well-supported by the aftermarket, but engine choice and condition matter enormously. Diesels can crack heads if overheated, the petrol V6s are belt-driven (a snapped belt bends valves), and rust plus tired driveline consumables are the reality at this age. A well-kept 4M40 or 6G74 LWB remains a genuinely good cheap tourer; a neglected 4D56 can be a money pit.
Engines & variants
2.6L 4G54 petrol (1st gen)
Engine
2.6L SOHC 8-valve carburettor/EFI petrol I4 (Astron II)
Engine code
4G54 / G54B
Config
I4 NA
Displacement
2555cc
Power
76kW @ 4500rpm
Torque
186Nm @ 2500rpm
Drivetrain
Part-time 4WD (dual-range, free-wheeling hubs)
Economy
13-16 L/100km real world
Tow (braked)
2300kg
Tow (unbraked)
750kg
Transmission
5MT, 4AT
Timing chain / belt / gear
Belt-driven (interference - replace ~100,000km)
Pros
- Simple, tough old Astron four - easy and cheap to work on
- No diesel injection complexity; runs on regular unleaded
- Smoother and quieter than the early diesels
- Huge aftermarket and wrecker support
Cons
- Genuinely underpowered in a heavy 4WD, especially the LWB
- Thirsty for the performance on offer
- Carburettor versions can be fiddly to keep tuned
- Balance-shaft and timing belt are scheduled service items
Known problems
high
Timing belt failure (interference engine)
The 4G54 is belt-driven and an interference design - an overdue or perished belt that snaps will bend valves and wreck the top end. On 30-40 year old cars history is often unknown.
Fix: Replace the timing belt, tensioner and balance-shaft belt on schedule (~100,000km / by age); confirm when it was last done before buying.
medium
Worn jet-valve / valve guides and oil burning
High-km Astron heads wear valve guides and the small jet valves, leading to oil burning, smoke on start-up and lost compression.
Fix: Head recondition - valve guides, seals and jet-valve service by a specialist.
low
Carburettor / EFI tuning and tired ancillaries
Carby versions drift out of tune; early EFI sensors, vacuum lines and ignition components are all decades old now.
Fix: Tune-up, replace perished vacuum/fuel lines and ageing ignition parts; budget a consumables refresh.
2.3L 4D55 / 2.5L 4D56 turbo diesel (1st gen)
Engine
Indirect-injection turbo-diesel I4 - 2.3L 4D55 (early), then 2.5L 4D56 with intercooler
Engine code
4D55-T / 4D56-T
Config
I4 turbo
Displacement
2346cc (4D55) / 2477cc (4D56)
Power
62kW (4D55-T) - 66kW (4D56-T)
Torque
172Nm (4D55) - 217Nm (4D56T)
Drivetrain
Part-time 4WD (dual-range, free-wheeling hubs)
Economy
9-12 L/100km combined
Tow (braked)
2300kg
Tow (unbraked)
750kg
Transmission
5MT, 4AT
Timing chain / belt / gear
Belt-driven (interference - replace ~100,000km)
Pros
- Economical and torquey compared with the 2.6 petrol
- Mechanical injection - no electronics to fail
- Good low-down grunt for slow off-road work
- Cheap to run and well understood by diesel shops
Cons
- Slow on the highway, especially the early non-intercooled 4D55
- Notorious for head-gasket failure and cracked heads if overheated
- Belt-driven (and interference) - belt neglect is catastrophic
- Smoky and rattly by modern standards
Known problems
high
Head gasket failure and cracked cylinder head
The 4D55/4D56 has a high compression ratio and a real weakness for blowing head gaskets and cracking heads (near the valves/prechambers) once overheated - blocked radiator, tired fan/viscous coupling or low coolant quickly cooks it. Repeat failures are common if the cooling system isn't fixed properly.
Fix: Pressure-test and machine/replace the head, fit a quality gasket, and fully restore the cooling system (radiator, thermostat, viscous fan). Treat any overheating history as a red flag.
high
Timing belt failure (interference engine)
Like the petrol, the diesel is belt-driven and interference - a snapped belt destroys valves. Often poorly documented on cars this old.
Fix: Replace timing and balance-shaft belts with tensioner on schedule; verify history before purchase.
medium
Injector / injection pump wear
Mechanical injectors and the injection pump wear at high km, causing hard starting, excessive smoke and lost power.
Fix: Diesel-specialist pump and injector rebuild; many have already had this done - ask for receipts.
2.5L 4D56 turbo diesel (2nd gen)
Engine
2.5L indirect-injection turbo-diesel I4 with intercooler
Engine code
4D56-T
Config
I4 turbo
Displacement
2477cc
Power
73kW @ 4000rpm
Torque
240Nm @ 2000rpm
Drivetrain
Super Select 4WD / SS4 (dual-range, full-time capable)
Economy
9-12 L/100km combined
Tow (braked)
2500kg
Tow (unbraked)
750kg
Transmission
5MT, 4AT
Timing chain / belt / gear
Belt-driven (interference - replace ~100,000km)
Pros
- Economical and torquey for touring with the SS4 driveline
- Mechanical injection - simple and serviceable
- Cheapest second-gen Pajero to buy and run on fuel
- Strong wrecker/aftermarket support
Cons
- Underpowered in the heavier coil-sprung NH-NL, slow when loaded
- Same head-gasket/cracked-head vulnerability as the 1st gen 4D56
- Belt-driven interference engine - belt neglect ruins it
- The 4M40 alongside it is the better diesel to seek out
Known problems
high
Head gasket failure and cracked head from overheating
The 4D56's high compression makes it intolerant of overheating; a tired radiator, fan coupling or thermostat leads to blown gaskets and cracked heads near the valves/prechambers - and it often recurs if the cooling system isn't fully sorted.
Fix: Machine/replace head with a quality gasket and completely refresh the cooling system; reject cars with overheating history.
high
Timing belt failure (interference engine)
Belt-driven and interference - a snapped belt bends valves. Service history is frequently incomplete on these older cars.
Fix: Replace timing/balance belts and tensioner on interval; confirm last change before buying.
medium
Turbo and intercooler wear
The factory turbo wears at high km causing lost boost, smoke and oil leaks; intercooler and boost plumbing can split.
Fix: Turbo rebuild/replacement and inspection of intercooler and boost hoses.
2.8L 4M40 turbo diesel (2nd gen)
Engine
2.8L indirect-injection turbo-diesel I4, chain-driven timing
Engine code
4M40 / 4M40T
Config
I4 turbo
Displacement
2835cc
Power
92kW @ 4000rpm
Torque
294Nm @ 2000rpm
Drivetrain
Super Select 4WD / SS4 (dual-range, full-time capable)
Economy
9-12 L/100km combined
Tow (braked)
2500kg
Tow (unbraked)
750kg
Transmission
5MT, 4AT
Timing chain / belt / gear
Chain-driven (gear/chain timing - no belt to snap)
Pros
- Chain-timed - no timing belt to fail, the diesel to seek out
- More power and torque than the 4D56, far better loaded/towing
- Strong, simple mechanical-injection diesel with great longevity
- Pairs perfectly with the Super Select driveline for touring
Cons
- Timing chain upper guide wears and can break up (sleeper problem)
- Still intolerant of overheating - head gasket risk like all these diesels
- Indirect-injection means it's noisy and not fast by modern standards
- High-km examples often need injector/pump attention
Known problems
high
Timing chain upper guide wear / chain stretch
The plastic upper timing chain guide wears thin and can break away; fragments can jam the chain and cause it to jump timing, with major engine damage. A 'trac-trac' rattle at idle is the warning sign.
Fix: Replace the upper guide (and chain/tensioner as needed) and check valve clearance around 90,000-150,000km; investigate any timing rattle promptly.
high
Head gasket failure from overheating
Like the 4D56, the 4M40's high compression makes head-gasket and cracked-head failure likely if it has been run hot - cooling neglect is the usual cause.
Fix: Machine/replace the head with a quality gasket; fully restore the cooling system (radiator, thermostat, viscous fan).
medium
Injector and injection pump wear
Mechanical injectors and the pump wear at high km, causing hard starting, smoke and lost power.
Fix: Diesel-specialist injector and pump service; many have already been done - ask for records.
3.0L 6G72 V6 petrol
Engine
3.0L SOHC V6 petrol (12v early, 24v later) with EFI
Engine code
Config
V6 NA
Displacement
2972cc
Power
105kW (early 12v) - 133kW (24v)
Torque
228Nm (12v) - 255Nm (24v)
Drivetrain
Part-time 4WD (1st gen) / Super Select SS4 (2nd gen)
Economy
14-17 L/100km real world
Tow (braked)
2500kg
Tow (unbraked)
750kg
Transmission
5MT, 4AT
Timing chain / belt / gear
Belt-driven (interference - replace ~90,000km / by age)
Pros
- Smooth, quiet and far more willing than the four-cylinder petrol
- Robust Mitsubishi V6 with good longevity when serviced
- Cheap to buy as petrol scares buyers off
- Plentiful parts and easy to work on
Cons
- Belt-driven interference engine - belt neglect bends valves
- Thirsty, with poor range unless on LPG
- Less torque than the diesels for sustained heavy towing
- Ageing EFI and emissions components on older examples
Known problems
high
Timing belt failure (interference engine)
The 6G72 is belt-driven and interference; a snapped or skipped belt bends valves and damages the heads. History is often patchy on cars this old.
Fix: Replace timing belt, tensioner and water pump on interval (~90,000km or by age); always confirm history before buying.
medium
Overheating from neglected cooling
Tired radiators, hoses and a failing water pump can overheat the V6, risking head/gasket damage.
Fix: Refresh radiator, hoses, thermostat and water pump (do the pump with the timing belt).
low
Ageing EFI sensors and idle issues
Idle speed control, coolant temp sensors and vacuum lines are decades old and cause rough idle or stalling.
Fix: Diagnose and replace failing sensors; refresh vacuum and ignition components.
3.5L 6G74 V6 petrol (2nd gen)
Engine
3.5L SOHC/DOHC 24v V6 petrol; later GDI direct-injection
Engine code
Config
V6 NA
Displacement
3497cc
Power
139kW (SOHC) - 153kW (DOHC/GDI)
Torque
289Nm - 318Nm
Drivetrain
Super Select 4WD / SS4 (dual-range, full-time capable)
Economy
15-18 L/100km real world
Tow (braked)
2500kg
Tow (unbraked)
750kg
Transmission
5MT, 4AT, 5AT (INVECS)
Timing chain / belt / gear
Belt-driven (interference - replace ~90,000km / by age)
Pros
- Strongest and smoothest of the period engines - effortless V6
- Best petrol for towing and highway work in the second gen
- Robust bottom end with good longevity when serviced
- Cheap performance if you can wear the fuel bill (LPG-friendly)
Cons
- Belt-driven interference engine - a snapped belt wrecks the top end
- GDI versions suffer carbon build-up, rough idle and fuel-system faults
- Thirsty - poor range unless on LPG
- GDI is fussy about fuel quality and needs periodic decarbon
Known problems
high
Timing belt failure (interference engine)
Belt-driven and interference - an overdue belt that lets go bends valves and damages heads. Tensioner failure is a common trigger.
Fix: Replace belt, tensioner and water pump on interval (~90,000km or by age); confirm history before purchase.
medium
GDI carbon build-up and rough running
The direct-injection GDI 6G74 accumulates carbon on intake ports, EGR and injectors, causing rough idle, hesitation, poor economy and fault codes.
Fix: Intake/EGR decarbon, injector service and quality fuel; some owners revert tuning or service the GDI system periodically.
low
Intake swirl/idle components and sensors
Intake-manifold flaps, idle control and various sensors age and cause idle and driveability faults on these older V6s.
Fix: Diagnose and replace failing intake/idle components and sensors.