FREQUENTLY ASKED QUESTION ABOUT WHITE SMOKE FROM EXHAUST
Q1: why does the exhaust port of the car emit white smoke when starting?
When starting, the exhaust pipe emits white smoke. The possible causes are as follows:
Broken or warped cylinder head.
Gasket failure.
The engine block is cracked.
Cracking of the engine block can cause coolant leakage in the engine combustion chamber and cylinder, which is very dangerous as one of the most common problems. This needs special attention.
Q2: what causes the exhaust pipe to emit white smoke when accelerating?
Maybe the air filter is dirty, as a result the air intake is insufficient. The carburetor is faulty, or the oxygen sensor in the exhaust pipe is polluted, which can not provide the correct information to the gas distribution computer. It may also be that one of the engine’s pistons is broken and the engine oil starts to burn. Naturally, the thick white in the exhaust gas is due to the high content of water in the exhaust gas.
If the coolant is insufficient or the engine is overheated, the cooling system can be pressure tested. If not, the gasket may also be leaking. It needs to be replaced.
Q3: what causes the white smoke in the exhaust gas to smell like gas?
Car smoke is usually water vapor or steam. Because water and carbon dioxide are generated after the gasoline is completely burned. Water is water vapor at high temperature. Water vapor is colorless and transparent at high temperature. However, when the temperature is lower than 100 ℃, water vapor will condense into water. If the condensed water drops are very small and suspended in the air, the water vapor will appear as white gas. The water drop discharged from the exhaust pipe is the result of condensation of water vapor generated after combustion of gasoline in the exhaust pipe and muffler. If there is water in the fuel or there is leakage in the cylinder head gasket, in this case, the driver can smell a smell of raw fuel.
If the cylinder pad of the engine cylinder is worn, a certain clearance will be generated, which will cause a large amount of water from the cooling system to enter the combustion chamber through the clearance. The incombustible water will generate water vapor after being heated and will be discharged directly from the exhaust pipe. In addition, some cars emit white smoke because they encounter the legendary “black-heart gas station”, where the fuel products are mixed with water by illegal businesses, but this situation usually starts to emit white smoke after a certain refueling, which is relatively easy to find out the reason. Replace the fuel if necessary.
Q4: what causes white smoke from exhaust at idle speed?
When the idle speed of a cold car is high, there will be more natural burning gasoline and more water vapor, which is related to the thickness of the exhaust gas and the size of the three-way catalytic mesh. Combustion chamber engines may get oil in them, which causes them to burn off and exhaust. This will also lead to white smoke. This problem should be solved quickly, because the longer the oil stays in it, the greater the damage to the spark plug, and the spark plug may need to be replaced.
Q5: what causes white smoke at the exhaust port when it is cold?
It should be normal for cars to emit white smoke in winter, because the gas emitted by cars is hot. When the hot gas is cold, it will become white gas. If it has nothing to do with winter, then it should be the leakage of cylinder gasket. The antifreeze runs into the silencer through the cylinder barrel and turns white when heated. Then the cylinder gasket can be replaced.
Q6: what’s the difference between white smoke emitted by diesel engine and gasoline engine?
A small amount of white smoke is normal. While a large amount of white smoke indicate that the air cylinder is flooded, the air cylinder mattress is flushed, or the water jacket is damaged.
The ignition mode of gasoline engine and diesel engine is different. Gasoline engine needs spark plug to ignite the mixture, while diesel engine only needs to reduce the mixture pressure to a certain space, which will cause the mixture to self ignite. White smoke from diesel and gasoline engines may be a sign of different car problems.
When the diesel engine emits white smoke, the working temperature of the engine can be increased. For example, when the water temperature is about 70 ℃, the color of exhaust smoke changes from white smoke to black smoke, which can be judged as poor atomization and oil dripping of the injector.
The diesel engine emits white smoke when it is just started and black smoke when the temperature rises. This shows that the cylinder pressure is insufficient. Although this pressure can maintain the start-up of the diesel engine, due to the low temperature during the start-up, part of the diesel oil will evaporate into steam and be discharged without combustion. Check the tightness of valve closure, gas distribution phase, whether the gasket of cylinder gasket or oil injection seat hole leaks, whether the cylinder is excessively worn, whether the piston ring is stuck or whether its opening is overlapped, etc., and then solve the problem.
When the diesel engine is running at high speed, it works unevenly, acceleration is not sensitive, temperature is too high, working is weak, and the exhaust pipe emits gray white smoke. This indicates that the injection time is too late. Check and adjust the fastening condition of the fixing screws of the connecting plate and the condition of the keys and keyways. Slowly advance the injection time to eliminate the white smoke and ensure the normal operation of the engine. If there is no improvement after the adjustment, check whether the timing adjusting screws of the plunger of each cylinder of the injection pump are out of alignment and take measures.
Conclusion
The problem of white smoke from cars cannot be ignored. White smoke may mean that your car is in trouble and requires special attention. If necessary, let the professional maintenance personnel check and repair the car.
