Holden Problems

This is one of those 'how long is a piece of string' questions. It all depends on where the oil leak is coming from and what is involved in fixing it. If it’s a simple loose fitting that can be tightened in a minute or two, then it won’t cost much. But if the leak is coming from a gasket that requires the entire engine to be removed and disassembled to replace, then the cost will be much, much more.

Oil and coolant leaks can emanate from a huge number of locations on a modern engine, Sometimes just finding the source can take longer than actually fixing it. The best approach is to thoroughly clean the engine of all oil and gunk, and then drive it and keep checking until the oil reappears and track it back to the source.

Rather than the new battery causing the headlights and wipers to come on, this sounds more like the lights and wipers were already playing up, coming on randomly for no reason, and killing the original battery when your back was turned.

This is a relatively common problem and can usually be traced back to the car’s body computer. If the computer starts to act up, it can switch on various things including lights and wipers, even though the car is locked in the driveway and the key is in your kitchen.

Try an auto electrician who is a bit more familiar with modern body computer set-ups, but in the meantime, there’s a quick trick you can try that might stop the car misbehaving. Disconnect the car’s battery and leave it overnight before reconnecting it. This can sometimes be enough to reset the body computer and the problem will go away. Beware, though, this fix might be temporary and may return some weeks or months later.

The starter motor would be a very good place to start looking for the problem. If the battery checks out (and that presumes you’ve load tested it, not just run a voltmeter across its terminals) and the addition of a second jump battery only just turned the engine over, then, the starter motor is a likely suspect.

But don’t forget things like a poor earth somewhere on the car or a dodgy ignition or starter button. Once the engine is running, check the power going into the battery. You should be looking at between 13.2 and 14.5 volts going into the battery with the engine running if the alternator is pulling its weight.

Just because the battery indicator is showing green, does not mean categorically that it’s in good health. It can produce a surface charge that might show 12 volts with no load on it, but can fall to its knees when you load it up with the starter motor.

Many engines lose rpm when they are sitting at a hot idle. The problem could be with the fuel or ignition systems, but could also be a stepper motor that either needs to be replaced or reset (to re-establish the correct idle speed).

The oil light will be flickering because the sensor is telling the computer that there’s not enough oil pressure being generated to lubricate the engine properly. In turn, that’s because hot oil is thinner than thick oil (which means less oil pressure) and the amount of oil pressure generated is directly linked to how fast the engine is running. Hot (thin) oil plus a slow idle, means a dangerous fall in oil pressure.

If the oil pressure light goes out when you rev the engine a little, it will probably be okay, but don’t drive it like that for too long. Once the idle speed is reset, the oil light should not flicker on again. If it does, change the engine oil to a thicker (higher viscosity) specification.

The most problematic of the Cruze transmissions were the six-speed automatic fitted to Cruzes built between 2011 and 2013. Holden actually instituted a special repair program for owners of these cars and extended the warranty period on those that had been repaired under the terms of that program.

The 2015 car you’re looking at should not have these problems, but the Cruze itself was plague by a long list of other faults including oil and coolant leaks, overheating, cracked cylinder heads and more. To be fair, the later the build date, the less likely the problems were to occur, but any Cruze needs a careful, independent inspection before money changes hands.

You were on a pretty good bet that the problem was a case of warped brake rotors, but it seems new rotors have not fixed the problem. In which case, you need to start looking deeper into the suspension and front end of the car. There could be a worn bush or ball-joint, or perhaps something in the steering needs tightening or replacing. A slightly bent stub axle could also cause this. Make a note of whether it happens in corners (left or right) under light or heavy braking or even when accelerating. This information will help a mechanic diagnose the problem accurately.

But don’t ignore this as the problem will only get worse as whatever is worn becomes more worn. Eventually, you’ll have a car that shudders all the time and is unsafe to drive.

The first conclusion many mechanics will arrive at is that the engine’s head gasket has blown, allowing the oil and coolant to mix. Have a look at the dipstick. If the engine oil is milky, then this is a very real possibility. Perhaps when the cylinder head was replaced, the gasket has not sealed properly.

But if the oil cooler was replaced because it was leaking into the radiator (which is pretty common) then you might find that the oil you’re still seeing is just residual oil from the previous failure, and not a problem at all. Even so, it would be wise to replace the coolant and flush the system to try to eradicate all traces of the old oil.

A workshop can perform a chemical-based test to see if the head gasket is leaking. It’s worth the relatively small cost to rule this out and begin to look elsewhere.

There could be a complex, electronic, fuel-supply or engine-management reason for this, and if that's the case, having the vehicle scanned would be a good place to start. Or, it could be a case of human behaviour that is skewing your fuel economy figures.

By which, I mean that when you got the car brand-new, you gave it the kid-gloves treatment, understanding that the brand-new engine needed to be run in and would appreciate a slightly easier start to life. Then, as the novelty wore off and the vehicle began to earn its living, you subconsciously grew a heavier right foot. And it is this that's seen the fuel consumption creep up.

Failing that, you might have an on-board computer that has been silently recalibrating itself, perhaps in conjunction with software updates at the dealership which you may, or may not have, been made aware by the dealer. To be perfectly honest, I'd find 6.4-litre per 100km average on a Colorado borderline unbelievable, and the sort of economy only a dedicated fuel-saving driver could even get close to. Ten litres per 100km, meanw

The most common way to do this is to lower the window completely via the button, and hold the button down for an extra five seconds. Then, close the window fully with the up button, and hold that for another five seconds. Usually, this will reset the windows so that the body computer knowns where they are and can operate the automatic up and down functions correctly.

In some cars, you can achieve the same by standing next to the car and holding the locking button down on the key fob for 30 seconds. If that doesn’t work, try the unlock button for the same 30 seconds.

There are literally hundreds of things that can cause a check-engine light in a modern, computer-controlled car. A problem with the ignition, fuel system, emissions-control system, air-intake, lubrication, cooling and much, much more can cause this light to illuminate.

The best way to proceed is to have the vehicle electronically scanned. That way, the computer can tell the mechanic where the problem is and, hopefully, precisely what’s causing the check-engine light to flicker on.

For the record, however, a common fault with the V6 engine in this series of Commodores is a stretched timing chain that the computer interprets as incorrect valve timing (which it is). Plenty of owners of this model have discovered this as the cause of their check-engine light.