SUMMER TROUBLES

New Zealand Herald, Volume LXXII, Issue 22010, 17 January 1935, Page 15

SUMMER TROUBLES

OVER-HEATED ENGINES A VARIETY OF CAUSES

The extremely hot summer at present at its height is responsible for a host of over-heating troubles becoming apparent in motor-vehicles, and many owners have encountered perplexing faults without realising their origin. There is a general tendency on the part of motorists to "leave well alone," that is, to clean or adjust no part of the engine of their car as long as the unit as a whole is functioning efficiently. Driving the car every day, it is almost impossible to sense the gradual fallingoff in performance, and the ultimate refusal of the engine to start or to run evenly, comes as a considerable surprise. Over-heating can be due to a variety of causes, but is, of course, hastened in hot weather. A dirty engine is always inclined to run hot, as is one with the spark incorrectly adjusted, or with the wrong carburetter setting. Other causes of over-heating are too finely-adjusted tappets, too wide a gap between the spark-plug points, or too light a grade of oil for summer running.

Other more obvious causes of an engine becoming unduly hot are lack of water in the radiator, an obstruction of any kind in the cooling-system, or slip in the fan drive. Few owners tako the trouble to drain the radiator occawonally, and to flush out the coolingsystem with a powerful jet from a hose. If this has not been done for some time, a surprising accumulation of rusty sludge is likely to be removed, thus clearing a serious obstruction.

The correct adjustment of the fan is also of importance. If the ordinary type of belt is either too tight or too loose, slip is: likely to result, so that the fan will not revolve at its correct speed, and is thus less efficient for keeping the motor cool. Owners who are in the habit of running with the fan disconnected, to enable their cars to warm up more rapidly, have found it impossible to continue this practice during the last few weeks. Incidentally it is ns well to remember that an elusive squeak or rattle can frequently be traced to an unlubricated fan spindle. Manv modern high-compression motors' tend to run hot, their normal efficient operating temperature being considerably above that of some of the older types. Consequently, they are more sensitive, and a comparatively small fault, say in the ignition, is sufficient to cause over-heating, and perhaps boiling. Sparking-plugs should be kept clean and correctly adjusted, if one of the greatest charms of the modern car, quick starting at all times, is tobe enjoyed.