Patrol
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
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
4.2L TD42T turbo diesel
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
2.8L RD28T(i) turbo diesel
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
4.2L TB42 petrol
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
3.0L RB30 petrol
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