Holden Commercial Range

Start with the basics. How old is the battery and what condition is it in? Sometimes you can check a battery’s voltage is at 12 volts with a meter, and have lights on the dashboard, and be tricked into thinking the battery is okay. But if the battery is worn out, when you turn the key to engage the starter motor, the extra load on the battery sees it lose the plot and nothing happens. You might hear a clicking noise, or you might hear nothing.

Modern engines rely heavily on electricity to run and will cut out if they aren’t getting enough voltage from the electrical system and, again, a dud battery can be the cause even if the alternator is working properly. You need to have the battery tested when a load is applied to it. If the voltage plummets when you apply that load, the battery is definitely ready for replacement.

Don’t forget the other basic stuff like the tightness and cleanliness of the battery terminals. Dirty or loose terminals can provide enough power to light up the dashboard, but can fail you when you apply the load of the starter motor.

This is not an uncommon problem with the head unit in a lot of makes and models. Like any other computer-driven piece of equipment, they have a finite lifespan and, once they’re done, they’re usually done for good. That’s why the dealer would be recommending to replace the unit rather than tyring to fix the one you have.

What a lot of people do is that this opportunity to upgrade to a newer, better head unit with better sound, better connectivity and more up to date apps. There’s loads of choice in the aftermarket and you can spend as little or as much as you want. Many owners also use this as a chance to upgrade speakers and perhaps add a sub-woofer or extra amplifier for much better sound. And you’re right; if the original unit died, a replacement of the same type may well have the same problems.

Just because you can’t see where coolant is escaping, doesn’t mean it isn’t. Equally, a lack of milky oil in the sump does not guarantee that the problem is not a head gasket-related one. Even an external leak from a hose or fitting can be hard to track down as the hot coolant evaporates before you have time to find the witness mark or the coolant drips on the garage floor.

Your best bet is to have the car’s cooling system pressure tested. A mechanic will pressurise the system and leave it for a period of time. If the system holds pressure, that’s a good sign that there’s no leaking. If it loses pressure, you have a problem somewhere in the closed-loop cooling system. That could indicate a problem with a radiator, hose, water pump, head gasket or even a split bore or cracked cylinder head.

But there’s one other check to make that might save you a lot of time and hassle. Takle a close look at the car’s overflow tank. This is also called the expansion tank and is designed to catch coolant as it expands (through engine heat) before allowing that extra coolant to return to the engine as the car cools down at the end of the trip. If this tank is leaking (even from a tiny crack) coolant that expands into it will be lost and the cooling system will appear to be continually losing coolant.