Holden Commodore Engine Problems

A problem like this could be caused by any number of things, James. Electronically interrogating the on-board computer is a wise first step, as the error codes that will result will possibly lead you straight to the offending component.

In cars like yours with electronic fuel-injection and engine management, there’s an array of sensors that need to send the correct signal to the car’s on-bord brain for everything to function properly. Replacing these sensors one by one until you fix the problem is a very time and cash consuming way of proceeding. Have the car scanned instead and see what fault codes show up.

Meantime, if I had to venture a guess, I’s say the problem sounds ignition related. An engine will often idle properly with no load on it, but when you select a gear, there’s suddenly load applied and, if the ignition system is not spot on, the engine can suddenly do all sorts of crazy things, including dropping cylinders. The other thing that occurs to me is that your battery might be low on charge. Injected engines absolutely do not like a lack of volts.

The VX had the old 3.8-litre V6; the VZ had the later Alloytec engine. I expect it would physically fit, but I would also expect the radiator and thermostat to be different. I wouldn’t recommend it.

No, the Commodore ute was only produced with V6 and V8 engines.

Without hearing the car firsthand it’s impossible to speculate on what might be wrong with your car, but I would suggest that it’s unlikely to be the spark plugs. Your best course of action would be to get a mechanic to check it for you.

The early VE model Commodore V6s certainly had all sorts of dramas with stretched timing chains that could run into thousands of dollars to fix. Holden changed the design of the chain and while it did help, we’ve still heard of later post-2008 model Commodore V6s exhibiting the same problem.

The problem is made worse (accelerated) by poor servicing, so if the vehicle in question doesn’t have an absolutely up-to-date service handbook with evidence of every scheduled service being carried out in full, we’d be walking away. Same goes for a car that rattles on first start-up, won’t idle properly or has a check-engine light illuminated on the dashboard.

The Alloytec V6 was known to have problems with the timing chain. There is no warranty on repairs as such, and with four years having lapsed since the work was done any warranty that might have existed has long since passed. You could contact Holden’s customer service (1800 033 349) and lodge your concerns with them.

First, pull the radiator overflow hose out of the side of the coolant reservoir fill neck and turn the steering wheel to the hard left to get room to get tools in. Laying on the ground undo the two screws on the front of the reservoir and screw on the frame rail, and you can then remove the reservoir.

I suspect it's not actually firing when you first start it, and it's the computer shutting it down when you try again. It could be that when you take the key out and go through your locking and unlocking procedure you are in effect rebooting the computer. It could be a problem with the computer.

These late Commodores (the very last of the locally-made Commodores, actually) do, in fact, have a history of fuel injector problems. Holden has claimed that poor quality fuel is the cause, but some technicians disagree, arguing that it’s a problem inherent in the injector’s design. Some owners have been told that it’s better to run these cars on 95 or 98-octane fuel, even though the LS3 V8 is rated to run on 91-octane ULP. But it seems even cars that have been run on the pricier brew are still recording problems with the injectors.

The faulty injectors send the engine into a potential lean-mixture situation, at which point the on-board computer intervenes and sends the car into limp-home mode to avoid engine damage. That’s why you’re seeing all those warning lights on the dashboard, while the injectors themselves are what’s causing the rough running you’ve reported.

There’s been no recall on Holden’s part, but the word on the street is that a Holden dealer will replace the injectors free of charge if you present the car at the dealership with the symptoms in evidence. Holden’s announcement that it will cease to trade in Australia should not affect this situation.

It’s possibly a blown head gasket. Have a mechanic check it for you.