Holden Commodore 2005 Problems

It's good news. Your car is indeed compatible with E10 fuel which means you can use the slightly cheaper fuel without risking damage to your vehicle. The car should also run exactly the same as it does on normal unleaded petrol, although you may find you use slightly more fuel per 100km. This should, however, be more than offset by the savings you'll make at the pump.

There are many, many things that can make a car overheat. A faulty radiator, collapsed radiator hose, jammed thermostat, blown head gasket, low coolant level, incorrect ignition or camshaft timing, faulty fuel injectors, the list goes on and on. So you need to have the car scanned electronically to see if a fault code is offered up that could be the cause or part of the problem. First, though, I’d have a close look at the obvious stuff like a leaking radiator or blown radiator hose to make sure that it’s not a really simple fix. Even a faulty radiator cap – as simple as that sounds – can lead a car to overheat.

To be honest, a 34-dgree ambient day should never be enough to make a modern car overheat, especially not one like a Holden Commodore which was designed here to easily cope with our weather and temperature extremes.

It’s interesting to note that you bought the car from a dealer, so it would be worth going back and checking the paperwork to see if the car was sold with any warranty. It’s doubtful, however, as a 2005 model car falls outside the boundaries of Victoria’s statutory warranty legislation (generally a used car must be less than 10 years old and have travelled less than 160,000km before a statutory warranty applies from a licensed car dealer). A good mechanic who knows this type of car should be able to sort it, but have it checked soon; continuing to drive it with an overheating problem is a sure way to make small problems bigger ones.

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.

Based on your mechanic's diagnosis it would seem that the oxygen (02) sensor is probably faulty and needs replacing. There is no connection with the car's heater. If there is a problem with the heater it's different one.

If you have been servicing your car regularly, changing the oil and oil filter, you shouldn't have too much sludge to deal with and I would use one of the additives available for the purpose at your local automotive store. Change the oil and filter at the same time as you put the additive in, then change the oil and filter again after a week or so of driving.

That it starts fine when it's cold and enriched, but not when it's warmed up and not getting any extra fuel suggests it could be a fuelling issue. Have a mechanic check the fuel pressure; it might not be getting enough fuel on hot restarts.

It is unusual that the airbag required replacing so soon, but the car is going on for eight years old and, as Holden said, the warranty expired some time ago. Where it was serviced wouldn't have had any influence on the failure, what Holden was telling you was that because you hadn't had it serviced at one of their dealers they would not consider a goodwill payment.