Holden Commodore Engine Problems

There would still seem to be a problem with the crank angle sensor. The symptoms suggest it, and the diagnostics back it up. Having replaced the sensor without solving the problem you need to look at things like the connector and the wiring that leads to the sensor.

It's the first time I have heard of "Croak" and I would be asking the dealer to explain what they mean by the term. It could be as simple as a valve lifter needing to be replaced, or it could be serious like piston slap, which is what affected the 5.7-litre V8 engine used before your engine. Have an experienced engine man listen to the engine during the warm-up phase to tell you what part of the engine the noise is coming from. Because your warranty is about to expire I would recommend you place your concerns on the record with the dealer and with Holden. You should also be aware that Holden's responsibility for the product it sells does not end when the warranty ends, there is no time limit on the company's responsibility under our consumer laws.

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 suggest it's a problem with the mixture, and I guess it's too lean. Check the oxygen sensors, if they are ok check the system itself.

It’s going lean for some reason and not getting the enrichment it needs to accelerate. Check the throttle body.

I would expect your car to return around 11.0 L/100 km, so yours is very poor as you say. You would have to allow for slightly higher fuel consumption due to wear on the engine, loss of compression etc., but I would still expect that you should get around 12 L/100 km. I would be checking the basics, like spark plugs, spark plug leads, air filters, fuel-injectors, and throttle body to make sure they are all in tip-top shape; then look at sensors like the oxygen sensor to make sure they are conveying the correct signal to the engine computer.

It could be a faulty shift solenoid or a problem with the throttle position sensor. Take it to an auto trans specialist who should be able to diagnose the problem for you.

If you feel it is a problem, and the presence of piston slap is not necessarily a problem in itself, you should keep meticulous records of your dealings with the dealer and Holden in case it does escalate into an issue that needs addressing. In that case you would be well armed with the information needed to support your case for Holden to act.

The idle mixture would appear to be incorrect. Check first for any possible vacuum leaks that might cause it to be lean and unstable at idle, also check the oxygen sensors and makes sure they are working correctly.

It would seem either the ignition switch or the neutral/park safety switch is faulty. I would guess it's the former. A mechanic or an auto electrician should be able to fix it for you.