Holden Commodore Problems

You're right to be concerned as there are lots of reports of problems with the Gen III engine. You're also right they can use oil at an alarming rate, and they can have a piston rattle. Holden has rebuilt lots of them under warranty, so I would ask the seller about any work that has been done on the engine. Ask for proof positive that work has been done if they say it has. Ask also for any records of oil consumption they might have kept. It's impossible to tell if an engine is using oil simply by looking at it, so you have to try to get as much info out of the owner as possible, and hope they're telling the truth. Check the service book for anything that might say it's been in for extra servicing, or had additional oil added. As for the noise, listen carefully for a light metallic rattle as you blip the throttle. There's no need to rev it hard, simply blip the throttle and you should be able to hear it if it does rattle. Keep it in the back of your mind that there are plenty of cars out there, so if you have any doubts about the car you're considering, walk away.

I would definitely dispute the need to do anything in this case. You should be able to detect a blocked injector. The engine should run a little rougher at idle and under load, but if it's not, I would suggest there is nothing wrong. The fuel consumption numbers you quote are in line with what I would expect from a VX II Commodore V6.

I have never tested any of these devices so I can't offer an opinion other than that I am sceptical of claims made for them. Others who have tried them might be able to provide information. If you have, send your comments to grah.smith@bigpond.com

Like you, Mick, I can't explain why the acceleration figures for the supercharged Commodore should be shown as similar to the non-blown car. It doesn't stand to reason. The figures shown on Holden's website are not Holden's own performance numbers. They are taken from a comparison test done by other people. Holden doesn't publish official performance data. The numbers I have suggest that the correct 0-100km/h acceleration number for the normal V6 is about 9.2 sec and the supercharged car gets the job done in about 7.5 sec.

There's virtually no similarity between the Bathurst racers and the road cars you and I buy from Ford or Holden, apart from a vaguely similar appearance. The engines are purpose-built 5.0-litre V8s. Neither Ford nor Holden have a production 5.0-litre V8 on sale. The gearboxes are purpose-built for racing and the suspensions are special, as are the brakes, wheels and tyres. The bodies may look like the production equivalent, but they're specially built, incorporating roll cages and other reinforcements. And get this: the Commodores now run a Falcon-type wishbone front suspension instead of the MacPherson strut the production cars run. The Commodore racers have long-run Ford nine-inch diffs as well.

Thanks Matt. I'm sure Virginia will be keen to check it out.

Your Falcon would have tested about 13 litres/ 100km when new. For comparison purposes, the Commodore V6 would return about 11.5 litres/100km, the 3.5-litre V6 Magna about 10.5 and the Camry closer to 13. Clearly, on that basis the Magna is the car for you.

You really need to have it checked by a mechanic. It could be oil being sucked into the engine past the valve stem seals and burnt, or it could be running very rich. If it is the latter it could be because of a malfunctioning oxygen sensors in the exhaust or the engine temperature sensor, telling the computer the engine is running lean or it's not up to working temperature, and forcing the computer to pour more fuel in.

I'm not aware of any Commodore clubs. There is a club for fans of Holdens from 1960 to 1980 which would cover your Commodore. Contact them on 0412 914 345. Alternatively, contact the Association of Motoring Clubs on 9555 0133.

You've done just about everything possible and seemingly without finding the cause of the problem. The Commodore of that era is prone to driveshaft vibrations. I would suggest you have the driveshaft angles checked as that is often a source of problems like you describe. It is almost certainly a drive-line problem.