Holden Commodore Engine Problems

Holden’s own recommendation is that E10 is fine for your model. There’s no reason to believe E10 would damage your engine.

On your figures it’s getting 19 L/100 km whereas it should be getting around 11 L/100 km. That says there’s something very wrong, and the petrol smell suggests it could be running very rich. It could be a problem with the oxygen sensor. Have it checked out.

The best system for your car is a vapour-injection one and IMPCO was the system used by Holden for the factory-fitted cars. But there are lots of other systems that would also perform well. All systems are made in Italy, no matter the brand. Choose a well-known brand and an experienced installer, and ask the installer for references from other owners who have had similar systems fitted. The vapour-injection systems are more expensive than the older technology venturi/mixer ones, and on average are priced around $4500.

I would put my money on the Crank Angle Sensor, even though you are willing to rule it out. It does sound electrical and the CAS is often the culprit in these deals.

It sounds like the engine is overheating and you should have it checked to determine the cause. If it is overheating be careful about driving it as you could de even more damage. Any mechanic could check it for you, it's not necessary to take it back to the place you bought it, unless of course you have some form of warranty and want them to cover the cost of the repair. You could trade it in if that's what you want, but dealers might be reluctant to accept it if it has a problem. The best course of action would be to find out what's causing the problem and have it repaired.

It does sound like a loose timing chain as the Holden dealer has suggested. We've had another report of a broken timing chain on an Alloytec engine and the result in that case was a badly damaged engine, so I would act quickly and have the chain checked and replaced if worn or loose.

The increase in consumption you report is certainly higher than would be expected, but that could be because you were towing. Try it again in normal day-to-day driving and see what you get. The expected increase in consumption is about three per cent and that should be offset by the lower price of E10.

While oil usage is something to watch your car isn’t using a lot of oil and the trade advice is that the 6.0-litre V8 doesn’t generally have a problem with oil consumption. I would check the oil regularly and if the consumption increases then take it back to Holden for investigation. As an aside most mechanics believe the factory specified service intervals are too long and strongly recommend changing oil more frequently, at 5000 km or so intervals.

The presence of exhaust gases in the coolant suggests it's either a head gasket leak or perhaps a cracked head.

It doesn’t sound like there’s anything wrong, the ‘smoke’ is pretty normal for most cars during the warm-up phase.