Holden Commodore Problems

The warranty covers you if the car has a problem, Holden is obliged to honour it and give you a car that is trouble free. Beyond that there is a requirement for any manufacturer, of any goods, to produce a product that is of commercial quality. If the oil consumption of your car doesn't improve you could claim it's not fit for the purpose for which you bought it. But I wouldn't rely on our consumer laws to get you a result.

Intermittent problems are always difficult to find if they don't occur when the mechanic is there to witness it, but I would be looking at an engine sensor, crank angle or O2, as the most likely cause.

We asked our contacts at Impco, the company that developed the system for Holden, and they are at a loss to explain what might be the cause of your problem. Generally the system is very reliable, which leads them to think it's an intermittent problem, something like an electrical connection.

The oil consumption is way too high. The engine should be pulled down to find the cause, and I would suspect that it is related to the problem you previously had with the engine.

We checked around and found that there are reports of fuel quality issues resulting in injectors being blocked. The issue is thought to be predominately caused by contaminants in the gas leaching plasticizers from flexible rubber hoses installed on some LPG vehicles, which then migrates to the injectors. The recommendation we were given is to inspect the car's fuel delivery lines and if they are rubber check their extractability rating. If the rating is not near zero, then have them replaced with either copper lines or zero extractable flexible lines.

It's not related to the fuel system as the Impco system starts on petrol every time, whether you've got the system switched to petrol or LPG. It's more likely to be an engine sensor, such as the crank angle sensor, which is playing up intermittently. Check the connections and the sensor itself. As for the warranty, you did the right thing in reporting while the warranty was in effect, so you could have a claim against Holden once the cause of the problem is  determined.

It's odd that these problems should start after you had the new radiator fitted. I would suspect that whoever did the work did it poorly. Take it to an air-conditioning specialist.

The system is designed to start on petrol every time, whether the switch is set to petrol or LPG, so there should not be any difference in starting. It sounds as though at times it could be trying to start on LPG instead of petrol. You should see an IMPCO specialist to have the ECM checked to make sure it is actually being told to start on petrol.

It does sound as though it is using too much oil. Sit down with the dealer and work out with them how they will tackle it, and press them for a solution. Also check the oil level weekly so you don't inadvertently run out of oil.