Holden HZ 1979 FAQs

Check out real-world situations relating to the Holden here, particularly what our experts have to say about them.

• My 2012 Holden Cruze is stuck in reverse

  The filling point for this transmission is on top of the gearbox, under the ECU (drive-line computer). So, to access it, you’ll need to move the computer (which attaches to the battery tray) out of the way. Take lots of photos before removing bits and pieces so you’ll know how it all goes back together.

  However, it’s doubtful that a lack of gearbox oil is your problem here. If the oil was low, the transmission would probably be making some seriously bad noises or would be completely seized up, not just refusing to shift out of reverse. The refusal to abandon reverse probably has more to do with a mechanical selector problem. But don’t rule out a worn or maladjusted clutch, either.

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• Why is the dashboard transmission light in my 2002 Holden Rodeo flashing?

  The coincidental nature of these faults would make most mechanics suspect the body computer is having a nervous breakdown. This computer is the one that controls functions ranging from central locking, the immobiliser, power windows, dashboard and even the entertainment system. It’s also responsible for the indicators, climate control and probably the gear selector. See the pattern?

  And because the computer itself – rather than an individual component – has gone on the blink, it won’t always throw an error code. An auto electrician is the first place to visit as your diagnosis of an electrical fault is almost certainly spot on. Don’t rule out a simple bad earth connection, either, as these can also cause electronic havoc.

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• Could my Holden Commodore have a manifold leak?

  A manifold leak will throw the engine’s fuel-air ratio out the window and can cause poor cold running and hard starting. The old school way of checking for a vacuum leak is to get the engine idling and then spray either carburettor cleaner (or something else flammable) around the intake area of the engine. If the engine suddenly picks up revs, you almost certainly have a vacuum leak. But be careful, spraying flammable stuff around a running engine comes with a fire risk.

  The other thing to check would be the throttle body and the sensor attached to it that tells the computer how much throttle has been applied. Again, these can start to give false readings, throwing the fuel-air mixture out.

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