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The VX Commodore arrived in 2000 as a refinement of the already hugely successful VT platform. Holden wasn’t trying to reinvent the wheel here—instead, the VX focused on improving reliability, refinement, and durability across the board. Under the bonnet, that meant continued development of the cooling system to better handle Australian conditions, heavier vehicle weights, and the growing performance expectations placed on V6 and V8 Commodores alike.
By this point, Holden had largely moved away from the old-school cooling systems found in earlier VN–VS models. The VX brought smarter thermo fan control, improved radiator efficiency, and better thermal stability, particularly in LS1-powered V8 variants.
Today, cooling system health is one of the biggest factors separating a reliable VX from one that constantly causes headaches.
Cooling System Overview
The VX Commodore used a fully pressurised liquid cooling system featuring:
Aluminium crossflow radiator
Electric thermo fan assembly
Belt-driven water pump
Thermostat-controlled coolant flow
Pressurised overflow bottle
Integrated transmission cooler on automatic models
Cooling system layouts varied depending on:
V6 or V8 engine
transmission type
towing package specification
HSV or performance model status
Radiator Design
The VX Commodore used an aluminium radiator with plastic end tanks.
Characteristics:
lighter than older copper-brass radiators
efficient heat dissipation
improved airflow packaging
compact engine bay fitment
Common issues:
Today, the radiator is one of the VX’s most common cooling system failure points.
Typical problems include:
cracked plastic end tanks
leaking seams
coolant staining near crimps
pressure-related fatigue failures
Most original VX radiators are now well beyond their intended lifespan.
Thermo Fan System
The VX used electric thermo fans across the range rather than traditional engine-driven clutch fans.
Benefits:
improved fuel economy
reduced engine drag
quieter operation
more precise cooling control
Fan behaviour:
The ECU controls fan operation based on:
coolant temperature
air conditioning demand
vehicle speed
V8 models rely heavily on proper fan operation, especially during low-speed driving and towing.
Water Pump
The VX Commodore used a conventional belt-driven centrifugal water pump.
Functions:
circulate coolant through engine and radiator
maintain stable operating temperatures
support heater core circulation
prevent localised hot spots
Common Water Pump Problems
Water pumps become a common wear item on ageing VXs.
Symptoms:
coolant leaks from weep hole
bearing noise or pulley wobble
overheating at idle
coolant smell after shutdown
On LS1-powered cars, reduced coolant circulation can quickly lead to overheating under load.
Thermostat System
The VX uses a conventional wax-pellet thermostat assembly.
Characteristics:
regulates coolant flow based on temperature
assists engine warm-up
stabilises operating temperature
supports fuel economy and emissions performance
Compared to later VE and VZ systems, the VX thermostat arrangement is mechanically simpler and easier to replace.
Common Thermostat Problems
Thermostat failure becomes increasingly common as these cars age.
Symptoms:
fluctuating temperature readings
overheating in traffic
poor heater performance
slow warm-up times
Fortunately, replacement is relatively straightforward on both V6 and V8 models.
Coolant Specifications
Holden specified long-life coolant suitable for mixed-metal cooling systems.
Recommended coolant characteristics:
corrosion-resistant formulation
aluminium-safe chemistry
anti-cavitation protection
long-life coolant compatibility
Why Coolant Quality Matters
Neglected coolant is responsible for many cooling system problems on VX Commodores.
Common consequences include:
radiator blockage
heater core restriction
internal corrosion
water pump wear
electrolysis damage
LS1 engines in particular dislike poor cooling system maintenance when driven hard.
Common VX Cooling System Problems
Radiator End Tank Cracking
One of the most common VX failures.
Symptoms:
slow coolant loss
coolant smell after driving
visible staining near radiator seams
Thermo Fan Failures
Symptoms:
overheating in traffic
poor air conditioning performance
fans failing to activate correctly
Fan relays and ageing motors are common culprits.
Heater Core Restriction
Often caused by neglected coolant maintenance.
Symptoms:
weak cabin heater output
inconsistent cooling performance
coolant contamination
Water Pump Wear
Symptoms:
coolant leaks
pulley noise
overheating during extended driving
Cooling System Service Components
Water Pump
Typical replacement window:
120,000–180,000 km
Radiator
Common lifespan:
10–15 years depending on climate and usage
Thermostat
Often replaced around:
100,000–150,000 km
Coolant
Recommended interval:
every 5 years or 100,000 km
Best Cooling Upgrades for VX Commodore
The VX responds extremely well to preventative cooling upgrades.
Popular upgrades include:
full aluminium radiators
upgraded twin thermo fan assemblies
low-temperature thermostats
silicone radiator hoses
alloy overflow tanks
external transmission coolers
engine oil coolers for towing or track work
Cooling Upgrades for LS1 VX Models
Modified LS1s quickly expose weaknesses in factory cooling systems.
Common supporting upgrades:
thicker radiator cores
higher-flow water pumps
upgraded fan control tuning
improved airflow ducting
larger expansion tanks
These upgrades become especially important on cammed, turbocharged, or hard-driven V8 builds.
The VX Commodore represents one of the best blends of old-school Holden simplicity and modern refinement. Its cooling system is straightforward, effective, and generally very durable when maintained properly.
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