Knowing When to Replace the Fan Belt
Question: A service-station attendant recently told me that my car needed a new fan belt. I was a little leery, but I went ahead and had it replaced at the station. How can you tell when a belt needs replacing?
--R.W.
Answer: The V-belts that run the engine cooling fan, the power-steering pump and other components can show signs of wear that, if spotted early, can prevent you from being stranded. You can drive a car--although not very safely--with a broken power-steering belt, but if the fan belt breaks, you risk ruining the engine if you drive even a short distance. That’s because the fan belt usually drives the water pump that draws coolant through the engine block. Without it, the engine quickly overheats.
The V-belt (it gets its name because it tapers off to a “V” where it fits in the pulley) is made of a rubber compound laid over fiber cords. The belt is driven by a pulley on the end of the crankshaft, and it loops over other pulleys to drive the alternator, the cooling fan, the water pump, the air-conditioning compressor and the power-steering pump. The same belt will usually drive the alternator and the fan, while you may have separate belts for the air-conditioning and steering units.
The most common sign of wear is cracking on the underside of the belt, where it rides in the pulley. As the belt gets older, the rubber loses its flexibility and begins to crack. Sometimes, oil and grease get on the belt; this can damage the rubber compound and cause the belt to slip in the pulley. A belt may have a shiny, glazed surface, which is a sign that it is slipping in the pulley. A glazed belt can usually be tightened and should continue to work properly, but a cracked belt should be replaced immediately.
A belt should easily last three or four years, if adjusted to the proper tension. It’s a good idea to have all of the belts replaced routinely every 30,000 to 40,000 miles when you have the engine tuned up. And you should also carry a spare fan belt in the trunk. Then if the belt on the engine does break, a tow truck operator may be able to replace it with your spare without having to tow you to a repair shop.
Q: The instructions for my 1966 Chevrolet Nova recommend changing the oil every 60 days. Is it advisable to follow this schedule using today’s improved oils? Could one safely follow a schedule similar to that now being recommended for new cars, such as every eight months or 10,000 miles?
--E.L.S.
A: The lubricating oils being manufactured today are of much higher quality than those that were available in 1966, when your car was built. You should be able to go longer than 60 days without an oil change, but eight months might be too long an interval. The oil will retain its lubricating properties that long, but the additives in the oil, which control engine deposits, acid buildup and other problems, wear out with prolonged use in the engine.
If you drive about 12,000 miles a year, change the oil about every six months or 6,000 miles. Use an oil that has a service designation of at least SE. You’ll find this printed on the label of the oil container or on the lid. This means that the oil meets the established requirements for virtually all gasoline engines, no matter what year the car was built.
Q: My Ford LTD has 70,000 miles on it and will not start if it has been sitting for a long time. After much pumping of the throttle and more than 150 turns of the starter, the engine will catch, but with a lot of white smoke out the exhaust. I had the carburetor checked. Can you help?
--W.T.B.
A: The problem could be in the electronic sensor, which tells the ignition system when to fire each of the spark plugs. This device has been known to short-circuit on some models as the car gets older. When it doesn’t work, the plugs don’t fire properly and the car won’t start.
The sensor measures the rotation of the crankshaft to determine when each of the pistons is at the topmost position. As you continue to crank the engine with the starter, the resistance builds up in the sensor and finally causes it to work properly, allowing the car to start. You get so much white smoke because the engine has been flooded while you tried to start it.
Have the sensor checked.
Patrick Boyle cannot answer mail personally but will respond in this column to automotive questions of general interest. Do not telephone. Write to Your Wheels, You section, The Times, Times Mirror Square, Los Angeles 90053.
