Modified Holden HZ Failed Roadworthy - Loganholme
I inspected a 1979 Holden HZ in Loganholme today. The engine bay had clearly received a lot of attention – heavily modified, supercharger installed, fuel system converted from carburettor to EFI. Someone had spent serious time and money making this car fast and loud.
Unfortunately, that’s where the effort stopped. Everything else on the car had been neglected.
The list of faults
This was one of the longest fail lists I’ve written in a while:
Leaking fuel tank – fuel was actively leaking from the tank. This is not just a roadworthy fail, it’s a fire hazard and an environmental hazard. Fuel leaks are one of the most dangerous faults a vehicle can have.
Leaking right rear axle seal – oil was leaking from the axle seal onto the tyre and brake components on the right rear.
Oil-contaminated rear brake pads – because of the axle seal leak, the right rear brake pads were soaked in oil. Oil on brake pads destroys their ability to grip. This wheel effectively had very little braking power.
Middle seat missing – a seat had been removed without a Queensland LK1 modification plate for the changed seating capacity. No mod plate means the seating configuration doesn’t match the compliance plate, which is a fail.
Windscreen washer not working – a basic check that takes two seconds. It didn’t work.
Windscreen demister not working – the blower fan couldn’t demist the front windscreen, which is a safety requirement for visibility.
Supercharger installed without a modification plate – any engine modification like a supercharger or turbo requires a Queensland modification plate to be legal. Without it, the modification is unregistered and the vehicle fails.
Fuel delivery system modified without a modification plate – the conversion from carburettor to electronic fuel injection is another modification that requires official documentation.
Straight pipe exhaust with no mufflers – the exhaust system had been stripped back to straight pipes with zero noise reduction. The owner asked me why this is a safety issue. A roadworthy inspection doesn’t just cover mechanical safety – it also covers environmental compliance. An extremely loud exhaust is harmful to the environment, to neighbours, and to anyone near the vehicle. It fails.
I couldn't even complete the test drive
A roadworthy inspection includes a mandatory test drive to check brakes, steering, suspension, and overall vehicle behaviour on the road. I was unable to do this because the car was simply not safe enough to drive. Between the fuel leak, the compromised rear brakes, and the undocumented modifications, taking it on the road would have been irresponsible.
This means the fail list could have been even longer. Any issues that only show up during driving – steering problems, suspension noises, brake performance, wheel bearing faults – couldn’t be assessed at all.
Modified vehicles and roadworthy inspections
If you’ve modified your vehicle, you need to understand that any significant modification requires a Queensland modification plate. This includes engine swaps, forced induction (turbo or supercharger), fuel system changes, suspension lifts, and seating changes. Modification plates from other states are not valid for Queensland registration.
I can issue LK1 modification plates for seating capacity changes ($250), but engine and drivetrain modifications need to go through an appropriate engineering signatory.
Building a fast car is fine. But it still needs to be safe, legal, and properly documented. Speed without safety isn’t something I can sign off on – and I won’t. Every vehicle I pass goes out on roads shared with families, cyclists, and other drivers. That responsibility matters more than any inspection fee.
