There’s nothing like a vehicle breakdown to spoil the beginning of your holiday. Every year thousands of motorists set off on their annual holidays, and many experience a failure or two. In most cases, an hour or so spent examining the car carefully before setting off would have highlighted any need for repairs.
While electronic management of many functions has reduced the amount of maintenance that an enthusiastic owner can do, a significant number of parts can still be serviced, or at least inspected, at home. Even if you’re not in a position to fix anything, you’ll be in a better position to deal with the garage than somebody who simply takes his car in for an annual check-up.
We’ve published many articles about servicing the previous generation of engines, so now we’ll concentrate on the latest designs. There’s not much you can do about the fuel injection, ignition and various other electronically controlled parts, but a surprising number of components haven’t changed very much. It’s worth buying a workshop manual, if you can find one for a reasonable price (but you can manage without one, by surfing the Internet). If you don’t own a computer, pop along to your local Internet café. You’ll be surprised at the amount of detailed servicing information available on the Net, even for the most obscure vehicles.
Modern designers like to hide the engine underneath a plastic cover (said to reduce cabin noise levels and “beautify” under-bonnet layouts). This cover can frighten most people into leaving the engine well alone, but a good engine inspection must start with its removal. It is usually kept in position by a few bolts or screws, and once they’re removed the engine will look more familiar. This is also a good time to inspect the engine from underneath, because there’ll be more light around without the cover. Look for signs of an oil or fuel leak, a loose or frayed wire, loose bolts, and corrosion on parts such as Welch plugs and cooling hose entry points. Have a good look at the heater hoses, too; they often get neglected.
Most modern engines have hydraulic valvegear that doesn’t need adjustment, so servicing entails replacing the various filters, engine oil and spark plugs. Oil and air filters should be replaced at the recommended mileages, but fuel filters tend to get blocked up at irregular intervals, so replace them every two years or so. It’s also worthwhile carrying a spare. A blocked fuel filter can cause hard starting, affect acceleration, or limit your top speed. Good news is that spark plugs last a lot longer than they used to, especially if they’re platinum tipped. If you’re using unleaded fuel, you should get at least 60 000 km out of a set. On some modern engines, you’ll need a special tool to remove the plug leads without damaging the end-fittings. Be careful when replacing the plugs because it’s very easy to get cross-threading. Good quality plug threads will be coated with anti-corrosion oil and should be installed without any additional coating.
Here are some tips to prevent overtightening: if the plugs have a captive gasket, turn the tool until a resistance is felt, and then turn through another 90 degrees if the plugs are new, plus an extra 30 degrees if the plugs have been used. Some plugs have a tapered seat, and these should be turned only through 15 degrees after feeling a resistance.If the engine has a timing belt, check it for signs of peeling, wear, cracks at the sharp corners where the teeth join the belted portion, hardening and oiliness. You’ll have to remove the timing belt cover to do this, but it’s usually a simple operation. Do not remove the belt, or try to replace it, unless you’re a very experienced home mechanic, because you’ll disturb the valve timing – leave it to an expert. Likewise, tensioning such a belt is also a lot more precise than tensioning a fan belt. You need a special gauge, and it has to be right, otherwise the belt will not last. Also, bear in mind that even if the belt seems to be in good condition, it should be replaced at the recommended mileage.
The modern flat grooved accessory belts that run on grooved pulleys are also far removed from the old-fashioned V-belts, and should likewise be set with special gauges. However, if your engine has V-belts then set them so that the longest run of the belt, between pulleys, has a play of about 15 mm. If the belt is too loose it could slip, and this may result in the alternator not charging enough, or the engine overheating. Tell-tale signs are that the belt and pulley will be excessively hot and the side of the belt will be shiny.
If you use your car mainly for short trips in town, then the cooling system will come under increased stress on a long trip. With time, rust and dirt tends to block some of the passages in the radiator, and the best way to remove this material is to reverse-flush the radiator. Undo both top and bottom hoses and force water through from the bottom of the radiator upwards using a hosepipe. You’ll be surprised how much muck will come out. Inspect the hoses for cracks, they should be neither hard and brittle nor soft and mushy. Even if you don’t flush the radiator, and you don’t feel confident enough to remove the hoses, you can still learn a lot from the exterior appearance. A hose that shows signs of old age where the clamp pinches it will also have weak walls. By the way, it’s a good idea to always use anti-freeze, even if you live in the tropics, because it contains an anti-corrosion compound.
If the water pump is noisy it’s a sure sign the bearings won’t last much longer. The fan blades should be carefully inspected for cracks, even if your car has an electric fan. Should a piece of blade break off, the fan will be out of balance, and the resultant vibration could break mounting brackets, and even the waterpump body.
This is also a good time to take a look at the battery. Clean the exterior and make sure the connections are clean and tight. If there are six filler openings then you have a normal, or low-maintenance, battery.Bring the electrolyte levels up to the MAX markings by adding distilled or demineralised water. In an emergency, such as when you’re faced with a dry battery while travelling, tap water may be used. If the battery has no filler holes, then it is a maintenance-free battery, and will need attention from a battery centre if it is not functioning properly. If the engine has an electronic control unit then don’t remove either of the battery connections unnecessarily, because it may affect the computer’s memory. When you replace a battery, most electronic control units reset themselves after being disconnected, and you may find that the engine will run badly for a while, but full performance should return after you’ve switched the engine off and restarted a few times.
The next step is to jack up the car and put it on stands. Any home mechanic worth his salt has at least two stands, because a jack should never be trusted. Take a good look underneath for excessive oil leaks, broken or frayed exhaust hangers, and perished or torn CV-joint covers. Many CV-joint failures are due to dirt getting past these covers and contaminating the grease inside. Brake pads and discs should also be inspected. Some cars have sensors that indicate when a pad needs changing, but if not then you’ll have to remove the wheels to inspect the pads and discs.
A useful tip is to mark the position of the wheels so that you can replace them in the same position to preserve the balance. The pads should be replaced, in sets that include both front or both rear wheels, when one or more of the pads are worn to within two millimetres of the metal backing. The discs should be smooth, ie show no sign of scoring or cracking. If you’re going to replace any brake items yourself, take some time to study the layout, taking note of the presence of sender units and wires for the wear-sensors and ABS units. Before removing the old pads, remove the master cylinder filler cap, and make provision to capture any brake fluid that may overflow.
You have to push the brake cylinders back to get the pads out, and this will cause the brake fluid level to rise and possibly spill over. Push the brake cylinders, behind the pads, very gently with a something soft, like a piece of wood, to prevent damage. The new pads, and the discs, should be kept free of dirt and grease because even one greasy finger-mark can upset the brake balance between wheels. You can remove glaze on the discs with 80 grade emery cloth, and remember to fill the master cylinder to the correct level. Lastly, the brakes should be bedded-in by gently braking a few times on a deserted road until the pedal feels normal.
While the car is still on stands, check the steering links and ball joints for wear. Ask somebody to move the steering wheel from side to side a small amount, so that play is accentuated. Replace any parts that show excessive wear. If the tyres show any uneven wear then try to find the cause. If it is not something obvious, then consult an expert.
Spend some time making sure all the lights work properly and that the windscreen wiper blades are still doing their job. Usually, the windscreen washers can be adjusted by trial and error, using a pin thrust into the hole to change the jet angle. Headlight adjustment has become too precise to be done at home, so you’ll have to go to a dealer.
Finally, after all your hard work, take the car for a test drive of at least an hour at 120 km/h, no matter who has worked on it, to make sure that everything is functioning properly. Those jokes about a car having to recover from its service are often true, and this means that your car should be serviced at least two weeks before you intend going away, so that any malfunctions that turn up after the service can be fixed in time.
Enjoy your holiday!
