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Top issues
21 known problems · 5 high
high
Chassis, sill and guard rust
All engines
high
Overheating / cracked head from marginal cooling
4.2L TD42 naturally-aspirated diesel
high
Head gasket / overheating under load
4.2L TD42T turbo diesel
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 Nissan Patrol →
Before: Patrol MQ/MK (160 Series, 1980-1987)
After: Patrol Y61 (GU, 1997-2016) →
Price (AUD)
$6k-$30k
Body styles
5-door wagon, Cab chassis, Hardtop / utility
Drivetrain
Part-time 4WD (dual-range, manual free-wheeling hubs)
Origin
Japan
Built in
Japan
Overview
The GQ is the live-axle, coil-sprung wagon that built the Patrol's hard-core reputation in Australia, sold as DX, RX, ST and Ti through a 1992 Series 2 update. Old-school part-time dual-range 4WD with solid axles front and rear, recirculating-ball steering and manual free-wheeling hubs - immensely capable, endlessly fixable and the backbone of the touring/aftermarket scene. Engine choice defines the truck: the gear-timed TD42 indirect-injection 4.2 diesel and the big TB42 4.2 petrol six are the heroes (the NA TD42 is famously near-indestructible but genuinely slow), while the RB30 3.0 petrol is the underpowered budget motor and the late RD28T 2.8 turbo-diesel six (1995-1997) is the one to be wary of - cracked heads and pricey, scarce parts. Every GQ is now 28+ years old, so condition, rust and service history matter as much as the badge: check chassis, sills, guards, swivel hubs and front-end wear before anything else.
Engines & variants
4.2L TD42 naturally-aspirated diesel
Engine
Indirect-injection 4.2L diesel I6, naturally aspirated, mechanical fuel pump, gear-driven timing
Engine code
Config
I6 diesel NA
Displacement
4169cc
Power
85kW @ 4000rpm
Torque
264Nm @ 2000rpm
Drivetrain
Part-time 4WD (dual-range)
Economy
11-13 L/100km
Tow (braked)
2500kg
Tow (unbraked)
750kg
Transmission
5MT, 4AT
Timing chain / belt / gear
Gear-driven timing (no belt or chain) - extremely robust
Pros
- Gear-driven timing - nothing to snap, legendary longevity
- Simple mechanical indirect-injection diesel, easy to work on anywhere
- Routinely runs past 400,000-500,000km with basic care
- The most sought-after GQ engine - turbos and pump mods are common and effective
- Cheap, abundant parts and bottomless aftermarket support
Cons
- Genuinely slow in NA form - struggles loaded, towing or in hills
- Marginal factory cooling; runs hot if a turbo is added without upgrades
- Mechanical injection gets smoky and hard-starting once tired
- All examples are now very high km and old
Known problems
high
Overheating / cracked head from marginal cooling
Factory cooling is borderline, especially once owners fit an aftermarket turbo and work the engine hard while towing. A tired radiator, weak fan clutch or low coolant lets it overheat and crack the head or blow the gasket.
Fix: Keep the cooling system fresh - recore/upgrade radiator, replace fan clutch and thermostat, and fit a quality intercooled turbo (not a cheap kit) if adding boost.
medium
Injector pump and injector wear
The mechanical injector pump and injectors wear at high km, causing hard starting, excessive smoke and lost power.
Fix: Diesel-specialist pump and injector rebuild. Many examples have already been done - ask for records.
low
Age-related ancillaries and seals
These are 30-year-old engines - expect perished hoses, weeping rear main and timing-cover seals, tired engine mounts and a smoky cold start.
Fix: Budget a consumables and seal refresh on purchase.
4.2L TD42T turbo diesel
Engine
Indirect-injection 4.2L diesel I6 with factory turbocharger, gear-driven timing
Engine code
Config
I6 diesel turbo
Displacement
4169cc
Power
~92-103kW
Torque
~333-380Nm
Drivetrain
Part-time 4WD (dual-range)
Economy
12-14 L/100km
Tow (braked)
2500kg
Tow (unbraked)
750kg
Transmission
5MT, 4AT
Timing chain / belt / gear
Gear-driven timing (no belt or chain)
Pros
- Factory turbo gives the 4.2 the torque the NA version lacks
- Retains the gear-driven TD42 bottom-end and ease of repair
- Far more usable for touring and towing than the NA diesel
- Strong base for further safe turbo/pump tuning
Cons
- Late factory TD42T used lighter internals and is not as bombproof as the early NA blocks
- Heat management is critical - hard towing can damage a worked engine
- Rare in factory form and commands a premium
- Aftermarket-turbo'd NA cars vary wildly in quality
Known problems
high
Head gasket / overheating under load
Turbocharging stresses the cooling system; neglected coolant, radiator or fan clutch under heavy towing can cook the head gasket or crack the head.
Fix: Upgrade radiator and cooling, fit an EGT/boost gauge, and keep the system maintained. Verify it isn't a cheap home-brew turbo install.
medium
Turbo bearing/seal wear and oil feed
Turbo bearings and seals wear with age and hard use, especially where oil-feed/return lines are tired or the unit was run hard.
Fix: Turbo recondition or replacement; ensure clean oil supply and let it idle-cool after hard runs.
medium
Lighter late-build internals
Post-1994 TD42T engines used lighter internals and are reportedly less indestructible than the early NA TD42, so a heavily worked example can be more fragile.
Fix: Don't over-tune; keep boost and EGTs sensible and the cooling healthy.
2.8L RD28T(i) turbo diesel
Engine
2.8L turbo-diesel I6, indirect-injection, belt-driven cam, EGR and oil cooler (Series 2)
Engine code
RD28T / RD28ETi
Config
I6 diesel turbo
Displacement
2826cc
Power
85kW @ 4400rpm
Torque
255Nm @ 2400rpm
Drivetrain
Part-time 4WD (dual-range)
Economy
10-12 L/100km
Tow (braked)
2500kg
Tow (unbraked)
750kg
Transmission
5MT, 4AT
Timing chain / belt / gear
Belt-driven (scheduled replacement ~100,000km)
Pros
- More economical than the 4.2 diesel
- Smoother and revvier than the big indirect-injection six
- Lighter over the front axle than the 4.2 engines
Cons
- Cracked cylinder head is a well-known, expensive design weakness
- Only sold here a few years - parts supply is poor and pricey
- No more power than the bigger TD42 but far less torque/longevity
- Belt-driven timing needs scheduled replacement (the only GQ engine with a belt)
- Widely regarded as the GQ engine to avoid
Known problems
high
Cracked cylinder head / weeping head gasket
The RD28 head has a known weak spot in the cooling passage between the intake and exhaust where cracks form; a weeping head gasket or coolant loss is often the first sign. It is the engine's defining fault and aftermarket/uprated heads exist specifically to address it.
Fix: Reconditioned or aftermarket cylinder head; keep cooling system in top condition and avoid overheating to prolong head life.
medium
Injector pump faults and parts scarcity
The injector pump is known to be troublesome and expensive, made worse by limited parts availability since the engine was only sold here for a handful of years.
Fix: Diesel-specialist pump rebuild; source parts early - some components are hard to find.
high
Timing belt service neglect
Unlike the gear-driven TD42, the RD28 uses a rubber timing belt that must be replaced on schedule; an overdue belt on an old engine is a real grenade risk.
Fix: Replace belt (with tensioner) on interval and confirm history before buying.
4.2L TB42 petrol
Engine
4.2L OHV petrol I6 - carburettor (1988-1992), then EFI (TB42E, 1992+), chain-driven
Engine code
TB42 / TB42E
Config
I6 NA
Displacement
4169cc
Power
125kW (carb) - 129kW (EFI)
Torque
325Nm @ 3200rpm
Drivetrain
Part-time 4WD (dual-range)
Economy
17-22 L/100km real world
Tow (braked)
2500kg
Tow (unbraked)
750kg
Transmission
5MT, 4AT
Timing chain / belt / gear
Chain-driven
Pros
- Strong, torquey big petrol six - the gutsiest factory GQ engine
- Tough and long-lived with maintenance; cheaper to buy than the diesels
- Simple, fixable, and responds very well to LPG (many are dual-fuel)
- Smoother and quieter than the indirect-injection diesels
Cons
- Very thirsty on petrol alone - poor touring range without gas or long-range tank
- Some examples crack cylinder heads (especially if overheated)
- Carby (pre-1992) cars can be fiddly to tune; EFI is preferred
- LPG-converted cars vary in install quality
Known problems
medium
Cracked cylinder head from overheating
Some TB42 petrols crack cylinder heads, typically after an overheat from a tired cooling system or hard work; a common reason high-km examples have had head work.
Fix: Maintain cooling system; recondition or replace head if cracked. Check coolant for combustion gases pre-purchase.
low
Fuel cost / thirst
Not a fault, but 17-22 L/100km is the reality; touring range is poor. Most owners fit LPG to make it affordable.
Fix: Quality LPG conversion or accept the fuel bill; long-range tank for remote travel.
medium
LPG valve-seat wear (poor installs)
Badly set-up gas systems with no flashlube can accelerate exhaust valve-seat wear on older heads.
Fix: Verify gas-install quality and lube/additive system; compression-test pre-purchase.
3.0L RB30 petrol
Engine
3.0L SOHC petrol I6 - carburettor then EFI (RB30E), chain-driven
Engine code
RB30S / RB30E
Config
I6 NA
Displacement
2962cc
Power
100kW (carb) - 114kW (EFI) @ 5200rpm
Torque
224-247Nm @ 3600rpm
Drivetrain
Part-time 4WD (dual-range)
Economy
15-19 L/100km real world
Tow (braked)
2500kg
Tow (unbraked)
750kg
Transmission
5MT, 4AT
Timing chain / belt / gear
Belt-driven (scheduled replacement)
Pros
- Cheapest way into a GQ wagon
- Smooth, well-known RB-family six that is reliable when serviced
- Lighter and a little less thirsty than the 4.2 petrol
- Simple and easy to find parts for
Cons
- Genuinely underpowered for the heavy GQ - slow loaded, towing or in hills
- Working it hard towing can stress the automatic transmission
- Still thirsty for its modest output
- Belt-driven cam needs scheduled timing-belt service
Known problems
medium
Underpowered - drivetrain stress when towing
The 3.0 is undersized for a 2-tonne-plus 4WD; owners who tow or load it heavily can overwork and damage the automatic transmission and overheat the engine.
Fix: Don't tow heavy with it; fit a transmission cooler and keep the auto serviced. Choose the manual for towing duty.
medium
Timing belt service interval
The RB30 uses a rubber timing belt that must be replaced on schedule; on a 30-year-old engine an unknown-age belt is a risk.
Fix: Replace belt and tensioner on interval; confirm history before buying.
low
Fuel thirst
Still drinks 15-19 L/100km for modest performance.
Fix: LPG conversion or accept the cost; not a fault.