Those who neglect doing a quick mechanical check-over – even of newer cars – before taking to the highway are begging to be stranded. We’re not talking about rebuilding the cylinder head or performing a line-bore on the crankshaft mains. Below are just a few reminders that may slip your mental checklist in the rush to get bags packed and kids fed.
Your family is counting on you to take a few preventative measures before you hurl them into the gauntlet of our national highway system.
Engine oil: Check your oil levels and the date you’re due for an oil change, preferably in your driveway before you embark on that first 29-hour leg. If you’re close to the manufacturer-recommended oil-change interval listed in your manual, then change it.
If you’ll be going long distances, consider opting for a synthetic motor oil. If you’re traveling in hot weather or pulling a trailer, a fully synthetic engine oil such as Mobil Super™ Synthetic can give you the extra protection against thermal breakdowns that you need. It will also cut friction losses in the engine and bump your fuel economy while creating savings that you’ll see magnified on a long drive.
Transmission and differential fluids: Did you forget about the other oil reservoirs in your car? Both your transmission and drive axle have their own lubricant supply. Check your owner’s manual for their change intervals, as they are quite a bit longer than engine oil. A regular oil-change shop can handle the greasy job of changing manual transmission oil and the differential oil. While they are under the car, have them give the drive-shaft U-joints and any other grease points a squirt of grease.
Hoses: Rubber hoses would last 10 years if all they did were sit on a shelf. In a car, they are regularly exposed to temperatures around the 212-degree boiling point. At high temps, the plasticizers that make rubber squishy leach out at a faster rate. Once a hose gets hard, it cracks and hot water spurts out. Look first at where both the input and output radiator hoses attach to the engine and to the radiator. The extra stress on the hose from the pipe collar and hose clamp means they typically crack and fail there first. Also check your heater hoses, which run from the engine (usually near the thermostat housing) into the firewall and back. Look for bulges or blisters, which indicate a weakness in the hose wall. If your hoses have cracks or blisters, replace them. It’s easier to do it now than in the 112-degree heat of Death Valley. As a precaution, buy a hose-patch kit at the local auto parts store.
Belts: Check the engine belts by turning them sideways with your hand so you can see the friction surface. If they’re at all ragged, torn, cracked or showing the fiber cords, it’s time for fresh ones. Newer cars often have one large belt, called a serpentine, which runs the water pump and all the accessories (A/C, power steering and alternator). If your car has less than 50,000 miles, it’s probably fine. Older cars have more than one belt to run these devices. Make sure they are all in good condition. If you hear loud screeches when you pull away from a stoplight, a loose belt is probably the cause. If they are loose – in other words, if your finger can depress the belt more than a half-inch of deflection at a point halfway between pulleys – the belt is stretched. If it’s old and worn, replace. If it’s not, you’ll have to retension it or it may fall off, usually at a really inopportune moment such as in the 2-mile backup at the turnpike toll booth.
Engine coolant: New vehicles come equipped with engine coolant designed to go 100,000 to 150,000 miles. If your car is less than four years old, check that the under-hood coolant reservoir – usually a clear plastic bottle that says “engine coolant” on the cap – is topped up.
Water is water, right? Wrong. Not all coolants are the same, and they don’t want to be mixed. Be sure to use the same coolant type as is already in the engine. You can tell the difference from the color. Green coolant is the most common, indicating an ethylene glycol-based coolant with a standard package of rust inhibitors. Orange is called Dex-Cool, originally developed by General Motors but manufactured by other coolant name brands under license. The jug should have a large “Dex-Cool” trademark on it. It is also ethylene glycol-based, but it has an enhanced package of corrosion inhibitors (and, hence, tends to be more expensive). If you have an older vehicle, check both the coolant reservoir and the radiator. If your coolant is rust-colored or looks like mucky pond water, it’s time for a change.
Tire pressure and tread: Tires are your contact with the road, and since losing contact generally results in the remains of your vehicle being vacuumed up, check ’em out. Most people believe the appropriate tire pressure is listed on the tire itself. Actually, the number on the tire is the maximum amount of pressure the tire can hold and, if combined with extreme heat and speeds, could lead to a blowout. Be safe. Look on your driver’s side door, in the glove compartment, or on the fuel filler door for the recommended tire pressures, and check the pressure before you leave with a good gauge (available from your auto parts store) and an air hose (available at the corner gas station). Low tire pressures waste fuel and, more importantly, cause the tire to run hotter from the extra friction.
Also, look at the tread on all four tires to make sure it’s not too worn or unevenly worn. Most new tires come with about 10/32” of tread depth. If your tire tread-depth gauge (just a buck or two at the parts store) shows less than 2/32”, it’s time for new tires. You can also use a penny. If the depth is below Lincoln’s shoulder, it’s time to change. If your tires are on the bubble in terms of wear, or have a bubble in the sidewall from a recent bounce against a curb, it’s better to install new tires now than to take a chance on them wearing out while you’re on the road.
Brake system: Brake fluid classified by the government as DOT3 or DOT4 (most brake fluid, in other words) is a hygroscopic mineral oil, meaning that it attracts and absorbs moisture. As it ages, it turns the color of maple syrup and begins rusting your brake components. Check your brake reservoir for the color of the fluid, and make sure that it is topped up to the “full” mark. If you haven’t had a flush in two or three years, get one before you leave. Water-laden brake fluid, besides causing damage to very costly brake parts, also lowers the fluid’s boiling point. A lowered boiling point can lead to a squishy brake pedal, which may provide more excitement than you want while descending out of the Rockies with a 24-foot camper in tow. If your car is newer, it may be running DOT5 fluid, which is silicon-based and not subject to water absorption. Still, you will want to flush this fluid per the recommendations in your owner’s manual.
Battery: If the battery in your car is more than a couple years old, check that the terminals are corrosion-free and the positive and negative leads are tight. If your starter sounds sluggish, it’s either corrosion or a dying battery. Don’t wait to be stranded with a dead battery. If it’s not a sealed, maintenance-free battery, have a gas station test the electrolytes. If it is sealed, they can check the output voltage. If there is corrosion – white chalky stuff on the terminals – clean it off with a wire cable-brush available at your local parts store. Secure the leads tightly. If one falls off while you are driving, it can cause a harmful “voltage dump” that can kill the alternator, so make sure everything is tight.
Test the car: Do a quick run up the local freeway to listen for noises, feel for shakes, and watch for trouble signs in the gauges. Don’t assume everything is fine just because you drive your car every day. This is a test, not a commute, so focus on your car. Do you hear grinding or moaning from the wheels? That could be a bad wheel bearing or a worn CV joint. Does the car pull? Check for alignment problems or worn tires. Does it shimmy or squeal under braking? Might be warped rotors or worn pads. Does the brake pedal feel soft? Might mean worn pads or bad fluid. Do the headlights flicker at idle? It’s probably a loose alternator belt, a dying alternator or corroded battery terminals.