Holden Astra Problems

Going back to first principles, anywhere that a power wire that should be insulated is allowed to touch an earthed part of the car is a potential source of a short circuit. As such, there are about a million places where a wire or cable carrying 12 volts from the battery could be shorting out by touching an earthed part of the car.

Typical sites of a short-circuit include anywhere where a wire runs through a metal bulkhead (say, from the car’s interior to its engine bay) anywhere a wire is continually flexing (the wiring inside a door jamb where it passes through the body) a switch of any sort or anywhere else where friction could have worn away the wire’s insulation. Sometimes the insulation just gets old and falls off the wire (Mercedes-Benz cars from the mid-90s were notorious for this).

The clue will be in what components have suddenly stopped working. Checking the fuse box to see what fuses have blown in response to the short circuit is also a good indicator or where to start looking. If you suspect the short-circuit is at the battery itself, there will be no need for forensic investigation; a short at the battery will produce a violent spark and lots of smoke. Unless, of course, the car is fitted with a great safety feature called a circuit breaker on or near the positive battery terminal. If you’ve suddenly lost all power to the car, that’s where to start looking.

Finally, don’t assume that a loss of power to the car or some of its components is due to a short circuit. Sometimes a fuse can simply fail for no good reason and call a halt to play. If you’re unsure, an auto electrician can work miracles that the rest of us cannot generally fully comprehend.

If it’s only the low beam light not working and we’re not talking about crash damage here, then you can change the globe at home. You’ll need a H7 replacement globe for the Astra, and the blown left-hand side globe can be removed by undoing a small, plastic access hatch inside the engine bay at the back of the light, squeezing the spring clip that holds the globe in its mount, and then removing the wiring plug. Then, you take the new globe and reverse the process, being careful not to touch the glass part of the globe as that can damage the new globe.

That all sounds pretty simple and it is if you’ve done it before, but it’s also a bit fiddly if you’re a first-timer. But before spending money at a workshop to have the globe changed, check out some of the bigger chain auto parts stores. Many of these have a free fitting service for things like wiper blades and globes.

A leak in the tail-light lens is a remarkably common problem in a lot of vehicles. It’s even more likely if the vehicle has previously been in a crash and the tail-lights replaced by cheap imported units. You’ll spot a leak like this by condensation that will form inside the lens on a warm day.

Your mechanic is correct, too, if water gets into the light unit, it can then make it into the boot or hatchback area. From there, it will wet the carpet or boot-liner and potentially run down inside the rear quarter panel or the area where the spare tyre lives, where it will sit and start the process of rusting the car’s metal. If there’s a musty smell when you open the hatch, then you probably have a leak and it needs to be fixed pronto.

You could have a fault with the car’s wiring. The starter-motor takes its power from the fat, red and black leads that attach to the battery, but it also needs a low-voltage signal from the ignition key that tells it to do its thing. If there’s any sort of loose or missing wire, you might not be making the necessary electrical connections. You could also find that there’s an on-board security system that is blocking the starter-motor from turning. You could even find that the ignition key has a flat battery and is not unlocking the car’s on-board computer.

You say that the battery has voltage, but I wonder how you checked this. You can often put a multimeter across the battery terminals and see 12 volts, but this can be what’s called a surface charge that’s strong enough to light up the dashboard, but then disappears when you put the battery under load (by trying to start the car). Attach the multimeter and check the voltage while actually trying to start the engine. You may find you have a dead battery after all.

This engine has a reputation for failed EGR valves which are part of the emissions control system and live within the rocker cover. Without this valve working properly, the car’s tailpipe emissions can be higher than they should be, as well as causing the oil leak you’ve noted. And any time you have oil hitting a hot exhaust system, there’s the potential for a fire.

In some cases you can simply change the EGR valve, but experience suggests that with some engines, the solution is to replace the entire rocker cover which will incorporate a new EGR valve. The parts can usually be bought online.

It sounds very much like the ignition barrel has failed and is jamming the key inside. But it could be something else, too. Modern cars often have an interlock between the gear selector and the ignition key. If the car isn’t in Park, it won’t release the key as a means of making sure you leave the car in a safe state (where it can’t roll away). If any of the micro-switches and sensors that control this function have failed (or are in the process of failing) you might find that to be the cause.

Unless the water has come up through the floor and somehow got into the seatbelt mechanism or parts of it, the most logical answer is that rainwater has entered through an open window, run down the seatbelt webbing and into the mechanism under the seat. Failing that, if the floor and carpet has somehow got wet in the past, some water may have leached into the mechanism.

The question is: how do you know this has happened? The pretensioners only ever fire in the case of a collision, so their condition is pretty much an unknown until you need them. If, however, you’re referring to the inertia-reel mechanism that locks the seatbelt when you pull on it suddenly, then I’m sticking with the open-window-rainstorm theory, as water could definitely run down the belt webbing and into this part of the seatbelt assembly. Failing that, the moisture could be condensation that collected if the vehicle had been stored in a damp environment for some time.

For a start, it’s never a good idea to drag a car anywhere with the wheels, hand-brake and steering locked. You can damage anything from the transmission, steering column, driveline and even ruin (flat-spot) the tyres.

If the clicking noise when you drive it wasn’t there before, then a mechanic would suspect that there’s been damage done to the front driveshafts. This would be consistent with the car being forcibly dragged along the ground. If you’re worried, have a mechanic check the car over and send the repair bill to your (now possibly ex-) housemate.

When you look at how the Park setting works in an automatic transmission, you can see how this could happen. Basically, Park is engaged by a small pin that (typically) slides into the transmission’s output shaft and locks it, preventing the shaft from turning and effectively locking the drive wheels.

The problem is that the Park pin (also called a pawl) is almost comically small for the job it has to do. The point being that Park pawls have been known to fail, at which point, the car will be free to move if the park brake isn’t applied.

Best practice when parking an automatic car is to stop where you want to park, but leave the transmission in Drive and apply the foot brake. Then apply the park-brake, take your foot off the brake and let the park brake take the weight of the car. Then select Park. You’ll still have the security of being in Park, but you won’t have the car’s weight resting on that little park pawl.

You might be lucky and simply have a low transmission fluid level thanks to a leak, or perhaps even a selector that is not properly connected to the transmission.

But the fact that the transmission works in Reverse but not Drive suggests something internally wrong. You could be looking at a broken torque converter, failed clutch or band, a faulty pump, blocked valve body or even a broken gear set. A transmission specialist is going to be your best bet here.