ENGINE KNOCKS

Taranaki Daily News, 26 November 1925, Page 14

ENGINE KNOCKS

A MESSAGE BY’ SOUND. DETECTING TROUBLE. Knock! Knock! Knock! Coming events cast their shadows before, and the experienced motorist usually cultivates a of hearing to the point where every little unusual sound in the engine or in the body of the car warns him of impending troubles. There is a great deal of satisfaction in driving along the highway and listening to the smooth running of a perfectly performing engine. By driving a car day in and day out, we grow familiar with the various pitches of sound, given forth by the car at various speeds. Therefore any sound that is out of the ordinary conveys its message to the driver’s ear and is the alarm which, if answered immediately, often prevents serious difficulties. THREE TYPES OF DRIVERS. There are three types of drivers. One fel’ow plugs along and never hears anything; another with a imagination never misses a sound. • Between these two extremes there is a happy medium, the wise driver who recognises sounds that are ominous and does not worry over the squeaks and noises that come and go with every change in the road. In a car that is properly cared for and frequently serviced, deterioration is . slow. A warning sound, therefore, is usually given out by the motor in ample time to remedy a fault. This warning may come in the form of a light knock or rattle and, if located immediately, the necessary repairs can be made before serious faults have developed. Sharp metallic or rattling sounds usually indicate loose connecting rods, carbon in the cylinders, spark knocks, etc. Deep sounding metallic knocks or thuds indicate trouble in the main bearSqueaking sounds are generally located in the spring assembly, in the body of the car, in the fenders ami hood joints, or in the friction areas of the hood, in dry bearings, generator brushes, etc. NEXT WHISTLING SOUND Whistling sounds mean leaks in the gasoline manifold, in the cylinder head gasket, in thfe spark gasket, in the exhaust manifold, etc. Blowing sounds generally come from the lower half of the crank case. These are often caused by a leak past the piston rings. Grinding noises generally ceme from the timing gears and chains. The location of annoying sounds in the car is often a considerable problem, and even an experienced mechanic may often be at a loss to locate the seat of the difficulty. There are numerous parts in the engine, such, as piston pins, cam-shaft bearings and a dozen and one other elements where the sound may be located, and the ‘ £ divining-rod” method is a simple but effective way to trace the noise to its source. USE ORDINARY STICK. Use an ordinary stick or switch about the size of your finger, taken from the limb of a tree, cut it to a three-foot length. Place it in your teeth or against the forehead, the other end near or .on that part of the car or motor that you think the noise is coming from. Put your fingers in your ears, and the sound will be heard and can easily be traced. An iron bar will do as well. A little knowledge is a dangerous thing, and if you are not really acquainted with the mechanism of a motor you may frequently do far more damage by attempting repairs, and it is far cheaper n the long run to call on an experienced, workman who is provided with the proper tools to reach the seat of the trouble at once. UNWANTED ADVICE TO DRIVERS. A SOURCE OF DANGER. Bad drivers are always being criticised. So far the bad passenger, who is not only a nuisance, but also a potential source of danger, has escaped comment. There are several types. Some err through sheer "ignorance, others owlw to nervousness. To my mind ( says a London writer) the worst offender is the ultra-nervous passenger who insists on dinning advice into the ears of the man at the wheel—often wrong advice given at the wrong moment. If the driver is at all nervous himself, the running fire of comment by the passenger is only likely to shake his confidence. AH passengers should remember that the driver sees far more of the road and what is happening on it than themselves. If he is experienced, his eyes are trained to the task. To inform him, as some passengers do, that a tramway-car is approaching or that- a level-crossing is closed, or that a party of people are about to cross the road, is challenging his intelligence. DISTRACTING ACTION. If ho is so blind that he cannot see this himself, he should not be driving. To call attention suddenly and in a startled voice to any unexpected danger that may arise may often distract his attention at a moment when he requires the full coneentration of his faeult.es.’ This type of passenger is by no means uncommon. Curiously enough, drivers themselves often make the worst passengers, because they visualise every possible, danger. They know, too, a tight corner when they see one. Often such a passenger will go through the motions of declutching with his foot and, down steep hills, of putting on the foot brake. Ihe ignorant passenger who knows nothing whatever about driving or road dangers is often the ’best man to have beside you. provided ho keeps quiet when you are proceeding over difficult crossings or when an emergency requires concentration. Al] passengers should make a point of never talkin" to the driver in such circumstances. °