Blue smoke indicates oil getting into the combustion chambers, and constant smoking is a sign of severe wear of the cylinder-piston group parts. The appearance of smoke during revving, after prolonged cranking with the starter, after long idling or immediately after engine braking indicates, as a rule, wear of the valve stem seals.
Black smoke - too rich mixture due to faulty injectors or sensors engine management systems. Blue smoke with an admixture of moisture (especially after the engine overheats) means that coolant has entered the combustion chamber through a damaged cylinder head gasket. If this gasket is severely damaged, the liquid sometimes enters the oil pan, causing the oil level to rise sharply and the oil itself to turn into a cloudy whitish emulsion.
White smoke, especially when the engine is not warmed up or in cold weather, is normal.
It is quite common to see a car standing in the middle of a city traffic jam with its hood open, emitting clouds of steam -engine overheating. It is better, of course, not to allow this, looking at the temperature gauge more often. But no one is insured against the fact that the thermostat, electric fan may suddenly fail, or the antifreeze may simply leak. If you missed the moment of overheating, do not panic and do not aggravate the situation. Overheating is not as scary as its possible consequences.
Never turn off the engine immediately - it will get a thermal shock and, possibly, after cooling down, completely will refuse to start. When you stop, let it idle - this will keep the fluid circulating in the system.
Turn on the heater to maximum power and open the hood. If possible, pour cold water on the radiator. Only after achieving a decrease in temperature, stop the engine. But never open the cap of the expansion tank immediately: on an overheated engine, a geyser from under the open cap is guaranteed. Do not rush, let everything cool down, this way you will preserve the health of the car and yourself.
[The article is taken from the website: VAZBOOK.ru]
Almost all car manuals recommend that the clutch must be depressed when starting the engine. This recommendation is only justified in the case of starting in severe frost, so as not to waste battery energy on turning the shafts and gears of the gearbox in thickened oil. In other cases, this is simply a recommendation to prevent the car from moving if a gear is engaged due to forgetfulness. This technique is harmful to the engine, since when the clutch is depressed, significant force is transmitted through it to the crankshaft thrust bearing, and when starting (especially cold) lubrication does not reach it for a long time. The bearing wears out quickly, the crankshaft gets axial play, and starting from a standstill begins to be accompanied by strong vibration. In order not to damage the engine, get into the habit of checking the position of the gearshift lever before starting and starting the engine with the parking brake on, without squeezing the clutch unless absolutely necessary.