Car Preventative Maintenance
Body panels rust, moving parts wear, weatherstripping and bushings stiffen and crack; cars inevitably get old. They can be kept running nearly indefinitely as long as replacement parts, either new or from junkyards, are available, but eventually the costs of upkeep outweigh the utility of the vehicle, and we can say that it has come to the end of its useful life.
Driver behavior and preventative maintenance can extend the life of a vehicle considerably. Jackrabbit starts and hard stops cause premature wear, as can skipping routine preventative maintenance. Repairing all paint scratches and chips immediately helps to keep rust in check, as does flushing salt from the vehicle during warm spells in places with icy winters. If your car has an interference engine, replace the timing belt, timing belt tensioner, and any other device (such as the water pump) driven by the timing belt at the recommended service interval. It is also important to correct engine or suspension trouble right away. Problems do not disappear on their own, and seemingly minor trouble in the undercarriage can damage more parts and even lead to catastrophic failure if left for too long.
More important than anything else is to keep everything lubricated and to replace any fluids which might become contaminated with particulates, moisture, or corrosive impurities. Don't put off learning that your car has transmission fluid until your transmission fails! Engine oil, coolant, transmission fluid, brake fluid, power steering fluid, and, on rear-wheel drive cars and trucks, gear lube all have finite lifetimes and must be drained or flushed and replaced from time to time. Performing this maintenance is worth the time and expense; the alternative is premature component failure, which can cost hundreds of dollars and even result in a collision. Delaying fluid changes beyond recommended service intervals hastens failure. Most quick-lube shops and all full-service mechanics will change these fluids on request, but usually charge considerably more for labor than they do for an oil change. You can save money by doing all fluid changes yourself, and avoid the inconvenience of having to wait around at the mechanic's shop or dropping off the car and getting a ride.
Keeping the following in mind will lengthen the life of your vehicle:
(1) Wax now or paint later.
Waxes make a car's finish shiny, but they serve more than just a cosmetic purpose. The layer of wax over a vehicle's clear-coat provides a mechanically protective layer against particulate abrasion, oxidation, nicks, and minor scratches, and keeps already-existing chips and scratches from corroding. Most paste waxes also protect against the UV damage that can cause paint to come off of vehicles in sunny climates. Wax your vehicle at least twice a year. Don't neglect flat-black metal trim components; special waxes are now available to protect these, as well.
(2) Change the timing belt at the recommended interval.
Most overhead-cam engines drive the camshaft with a notched belt called a timing belt, usually kept under a cover on one end of the engine. If this belt snaps, valves and pistons are likely to collide, necessitating that the top half of the engine be rebuilt, an expensive proposition, often more expensive than the cost of replacing an economy car. Check your vehicle's owner's manual or telephone a dealership to determine the recommended service interval for your vehicle's timing belt. 60,000 miles is standard but some vehicles have longer service intervals. Don't try to save money on this by replacing just the belt, either; the tensioner, idler pulley (if any), and water pump should be replaced at the same time.
(3) If your vehicle as solid lifters, don't neglect valve service.
Most Toyota and Hyundai engines and quite a few others now use solid "bucket-and-shim" valve lifters to couple the camshaft to the valves. Shims wear with age, leaving too large a gap between the camshaft and lifter. This throws off timing slightly. Modern computer-controlled engines can compensate, but with some loss of power and economy as the car ages. Leaving too much lash will cause premature camshaft wear, leading to further loss of power. Wear-and-tear on valve seals, piston rings, and bearings will cause engines to become a bit less efficient with age, but there's no need to lose power because valves are out of spec. Check the valve lash with feeler gauges at 60,000 miles and every 30,000 miles thereafter, and replace the shims if necessary.
(4) Have alignment service done yearly, or every time you service front-end components.
Out-of-alignment wheels not only cause tires to wear prematurely; they also put abnormal stresses on suspension components. It's difficult to align a vehicle in a home garage, especially without a hoist. Once a year (or every 15,000 miles), every time front-end components are dismantled or replaced, and whenever the vehicle "pulls" noticeably to one side, take your vehicle to a professional shop for an alignment.
(5) Change engine oil every 5000 miles
Combustion byproducts and moisture from the air blow by the piston rings every time an engine cylinder fires. The amount is minuscule, but it adds up over time to contaminate the engine oil. Heat and some of these byproducts break down or react with some of the compounds in the oil to change its viscosity and reduce its lubricity. These changes to the oil are reflected in the darker color, increased opacity, and more acrid odor it develops over time. Additionally, the sulfur compounds that lubricate metal surfaces, like cylinder walls and piston rings, that aren't or cannot be coated with a film of oil all of the time get "used up" up over time; if you wait too long between oil changes, metal will start to rub against metal. Of all of a car's fluids, engine oil must be changed most often, every three to five thousand miles or six months, whichever comes first.
Fortunately for us, auto manufacturers make it easy to change the engine oil. You will need fresh engine oil, a drain pan, a new oil filter, and box or combination wrenches to do it yourself. Most auto parts stores put a reference book near the oil filters listing the correct part number for nearly every auto sold in the last half-century. Use the weight of oil recommended in your car's owner's manual. 10W-30 is most common, but many older vehicles with wider clearances require 10W-40. An oil filter wrench will come in handy; I prefer the kind made of a nylon strap and a steel post. Have a few rags and a good hand cleaner like Gojo or Fast Orange on hand; this job is inevitably messy.
Drive the vehicle around the block a few times to get it warm, then raise it and support it with ramps or a jack and jackstands. (Never get under a car supported solely by a jack.) Locate the oil filter and the oil pan on the underside of the engine. Place the drain pan underneath and slightly to the rear of the drain plug on the oil pan. Use a combination wrench to loosen the drain plug, then remove it by hand. Let the oil drain for several minutes. Grease or oil the threads of the drain plug and replace it in the drain pan, tightening it to finger-tightness with the wrench.
Next, move the drain pan to underneath the oil filter. Clean any grime or dirt off of the filter, dry it with a rag, and spin it off. If it won't come off by hand, use an oil filter wrench. Lubricate the gasket of the new one with some grease or oil, then spin it on by hand, finger-tight. Do not tighten it with the oil filter wrench. Fill the engine with enough fresh oil to come to or near the correct marking on the dipstick. Oil is refilled either through a tube or a hole in the valve cover; the cap will be clearly marked in either case.
If the oil has a milky appearance, make an appointment with a mechanic or get ready for a lot of work. Milkiness indicates water or coolant in the oil, which is a sign of a head gasket that is leaky and about to fail.
(6) Grease the suspension, if possible.
If you own a car with grease zerks, it is generally a good practice to lubricate the suspension every time the oil is changed. Nearly all cars built before the mid-1990s had grease zerks; many pickup trucks and SUVs still do. Locate the zerk fittings on the ball joints, tie rod ends, and often but not always on the driveshaft U-joint on rear-wheel-drive vehicles, and pump some grease into the joint with a grease gun. One or two pumps of the grease gun handle is usually sufficient.
(7) Change coolant before it becomes corrosive.
Engine coolant slowly becomes corrosive over time, and needs to be changed periodically to avoid damaging the water pump or radiator. Traditional "green" coolant should be changed every 20,000 miles; Dex-Cool "orange" long-life coolant needs to be changed every hundred thousand miles or five years, whichever comes first.
Raise and support the vehicle, then depressurize the cooling system and open an air inlet by removing the radiator cap or, on cars without removable radiator caps, the fluid reservoir cap. Do not do this while the system is hot, as you can be severely scalded by steam or hot coolant spray. Locate the drain valve at the bottom of the radiator, usually near a corner, place a drain pan underneath, and loosen the drain valve to let the coolant out. If you cannot locate a drain valve, drain the coolant by removing the lower radiator hose.
Close the valve or re-attach the hose, and refill the system with distilled water. Leave the radiator or reservoir cap off. Turn the engine on and let it run until the thermostat opens, allowing coolant to circulate between the engine and radiator. Stop the engine, drain again and flush once more with distilled water in the same manner. After two flushes, refill the system with a 50/50 mix of distilled water and the appropriate (orange or green) antifreeze.
A cooling system with a removable radiator cap will have to be "burped", to get air out of the radiator. Like burping a baby, this can get messy. After the final flush, leave the radiator cap off and place a drain pan under the filler hole. Start the engine and run it until the thermostat opens. Watch the coolant level when this happens; if it drops, top the system off. Wait for air bubbles to make their way to the filler neck. Sometimes when this happens, it will cause coolant to spill out and into the pan. Just keep replacing the spilled coolant until several minutes can go by without any more "burping". Shut off the engine and replace the radiator cap on the filler neck.
(8) Transmission fluid must be changed as well, usually every 30,000 miles.
Most automatic transmissions are filled with a sticky, smelly, red oil called, appropriately enough, "Automatic Transmission Fluid". Some manual transmissions are filled with this, some with ordinary motor oil, and some with gear oil. These fluids don't have to be changed as often as engine oil, because they don't get as hot, but they still break down over time. Check your car's owner's manual for the correct choice of fluid and service interval. 30,000 miles is typical, and changing the fluid more often than is recommended won't hurt the system.
Before beginning this job, you will need to purchase, in addition to the appropriate transmission fluid, a transmission pan gasket and a transmission filter from over the counter at the local auto parts store. You will also need a torque wrench, as most modern transmission housings are made of cast aluminum, with bolt holes that are easy to strip. It is possible to repair stripped threads with something called a "helicoil", but it's no fun and can lead to more trouble if you break off a tap in a blind hole. (Trust me, I've done it!) Just use a torque wrench from the start to avoid problems. If you do not own one, many auto parts stores have loaner units available.
Drive the vehicle to warm up the fluid, then raise it and support it. Place a drain pan underneath one end of the transmission pan, then drain the fluid by loosening the pan bolts progressively from one end to the other, so that the pan tips one way as it comes off. Let the fluid drain, then remove the pan completely. Clean the pan using citrus degreaser or denatured ethanol, taking care to remove any metal shavings from the pan magnet, if present.
Apply a bead of silicone sealant to the mating surface of the pan and place the new gasket (or old gasket on vehicles with reusable pan gaskets) on the pan. Allow this to cure for a little while, but not completely, then apply a second bead of silicone to the top of the gasket. Replace the pan on the transmission and tighten the pan bolts to the manufacturer's specification (this can be found in a Chilton or Haynes manual, the official service manual, or on the Internet), usually approximately 12 foot-pounds.
Refill the transmission with fresh fluid. If there is no dipstick, look for a level set plug on the side of the transmission housing. Remove the plug and fill the transmission until fluid leaks out of the hole, then replace the plug.
(9) Don't neglect gear lube, every 100,000 miles.
The gears and limited-slip mechanism in a rear-wheel drive car's differential are also lubricated, by a fluid even stickier and smellier than automatic transmission fluid, commonly called "gear lube". This doesn't get as hot as transmission fluid, and breaks down very slowly, but does accumulate metal shavings over time and should be changed every hundred thousand miles. Changing this is similar to changing transmission fluid, except that there is no filter. Drain the gear lube by removing the differential's cover, then replace the cover and refill with fresh gear lube.
(10) Change power steering fluid every 60,000 miles, to prolong the life of steering components.
Power steering is achieved by means of hydraulics. A belt-driven pump is used to assist the driver in turning the front wheels one way or the other. The working fluid can absorb a bit of (corrosive) moisture over time, and also tends to accumulate particulates. Changing it every two years or sixty thousand miles will prolong the life of the expensive power steering pump and lessen the chance of failure of the even more expensive steering rack.
There are two easy approaches to changing the power steering fluid. One is to draw most of the fluid out of the reservoir with a turkey baster, replace it with fresh fluid, drive as usual, and repeat the process daily until the fluid in the reservoir is the same color as the fresh fluid. The other is to remove the power steering pump return line from the fluid reservoir, directing it to a drain pan. Remove the old fluid from the reservoir, top off with new fluid, then turn the steering wheel both ways to help drain fluid from the power steering system, top off the new reservoir with fluid, and repeat as necessary. This is easier with an assistant. Have the assistant turn theengine on and turn the steering wheel back and forth; keep topping off the reservoir until the fluid coming out of the return line is the same color as the fresh fluid, then have the assistant turn theengine off. This approach is somewhat risky; don't let the power steering pump run "dry" during this procedure, and try not to let any air into the system.
(11) Brake Fluid absorbs moisture; change it every time brakes are serviced, or every two years.
Brakes are hydraulic, too. Your car's brakes operate much like a jack, transforming a large but low-force displacement of the pedal into a small but extremely high-force squeezing of the shoes or pads against the drum or rotor. Brake fluid is extremely hygroscopic, and over time can absorb enough water to become corrosive or to have too low a boiling point to be reliable. (Hot brakes can cause the fluid to boil, which can cause brake fade.) Moreover, the brake fluid can accumulate air bubbles, which cause a "spongy" feel. Change the brake fluid every two years.
Changing the brake fluid is best done with a partner. Raise and support all four corners of the vehicle and remove the wheels. Remove old brake fluid from the master cylinder with a turkey baster, and top off with new brake fluid. Have your partner press the pedal to the floor and signal you when this is done. When you get the signal, open up the bleeder valve (located near each brake caliper). Opening the bleeder valve is made easier with a special wrench available at most auto parts stores. Repeat, toppng off the master cylinder as necessary, until the fluid runs clear, then close the bleeder valve and repeat at each wheel. If the car is equipped with antilock brakes (ABS), have the assistant depress the brake pedal with the ignition in the "on" position (no need to start the engine), then turn the ignition to "off", all the while holding the pedal down. Open the bleeder valve when the ignition is "off", top off the master cylinder, and repeat as necessary.
It is possible to perform this job yourself if you cannot locate a partner, using a hand vacuum pump and a set of adapters. Kits are sold by Mityvac and others. The principle is the same as above, but the fluid will be pulled out by vacuum instead of being pushed out by the master cylinder. Follow the directions that come with your particular kit.
(12) If you own a high-end vehicle, consider rebuilding or replacing your engine if the rest of the vehicle is in good condition.
Rebuilding an engine can be expensive and time-consuming, but is worthwhile on some more expensive vehicles, which can be said to outlast their piston rings and main bearings.
