Smokes in the cold

machine smokes in the cold most often when valve stem seals are worn, when piston rings are stuck, when using unsuitable viscosity or simply low-quality engine oil. On diesel engines, this can be a symptom of problems with the glow plugs, with the fuel system (high pressure pump) and manifests itself when using off-season diesel fuel.

Situation	Cause the smoke on the cold
Smokes on cold start	valve stem seals worn out; partially sunk piston rings; faulty ICE sensors; poor quality fuel.
Smokes in the cold, and then stops	incorrectly selected oil; low-quality or clogged oil (and sometimes fuel) filter; leak injectors.
Smokes white smoke when cold	antifreeze gets into the cylinders; a lot of condensate that evaporates through the exhaust pipe.
Smokes blue when cold	a small amount of oil entering the cylinders due to faulty MSCs or piston rings; low viscosity engine oil.
Smokes black smoke on cold start	re-enrichment of the fuel mixture; diesel engines may have black smoke if the glow plugs are not working properly.

Why smokes on a cold gasoline engine

The reasons why a gasoline ICE smokes on a cold one completely coincide with both injection and carburetor power units. This is due to the fact that, usually, the problems lie not in the power supply system of the motor, but in the operation of the unit itself. in order to understand why there is smoke on a cold ICE, you need to look at its color. Exhaust gases can have a different shade - but most often, it is white, gray or dark blue smoke. The cause of cold smoke may be one of the details and materials further considered.

Clogged oil seals

The basic task of oil caps is to prevent engine oil from entering the cylinders. However, when they wear out, a small amount of oil may seep into the combustion chamber. Two situations are possible here. The first is that on a cold internal combustion engine, the gaps in it are smaller, therefore, after starting the internal combustion engine, the oil seeps a little into the cylinders during operation, but then the gaps increase and the oil stops leaking. Accordingly, after a few minutes of ICE operation, the blue smoke from the exhaust pipe stops.

Another case implies that some ICEs are designed so that a small amount of oil can get into the cylinders when the car is idle. Similarly, at start-up, this oil immediately burns out, and after a few minutes the exhaust returns to normal and the car no longer smokes oil.

Piston rings stuck

Quite often, the internal combustion engine smokes when starting on a cold one due to the fact that the piston rings “lie down”. At the same time, both gray and white smoke can come out of the exhaust pipe.

A lot of oil can get into the cylinders, including due to stuck piston rings. After warming up, until the problem worsens, the piston work is getting better, and accordingly, it smokes when it is cold, and then stops when the engine is hot. Also, the problem may go away after decoking the internal combustion engine.

If it smokes white when cold, then this indicates the presence of coolant (antifreeze) in the cylinders. However, antifreeze usually enters the cylinders through the cylinder head gasket. For example, if it is somewhere in one place is not pressed or damaged. If the cylinder head is not tightened enough, smoking with white clubs may stop after warming up due to the expansion of the metal and the restoration of a snug fit of the surfaces.

To find out what condition the rings are in, disassembling the internal combustion engine will help. However, before that, it is better to check the compression of the internal combustion engine. If you do not resort to repairing the internal combustion engine, then oil additives help to temporarily solve the problem.

incorrectly selected oil

This reason is typical for worn-out ICEs with serious mileage. The fact is that in most cases, the automaker allows the use of engine oils with different viscosities, depending on the condition of the car's internal combustion engine. If the motor is worn out, then the gaps between its rubbing pairs will be large, for example, on piston rings. Accordingly, thinner oil can seep into the cylinders until the engine warms up and the gaps increase. With thick oil, this cannot happen.

How to choose oil

the correct selection of engine oil will affect the operation of the vehicle’s internal combustion engine. In order to choose the best oil for internal combustion engines, follow the recommendations of the car manufacturer and look at the specifications, tolerances, as well as originality Read more

 

There are cases when the car smokes when it is cold, even though the viscosity of the oil, as it would seem, is chosen correctly. This is due to its low quality, in other words, a fake or low-quality oil is poured into the engine. For some motorists, the car may smoke when cold, then it stops after oil filter replacement if it also turns out to be fake.

Condensation in the exhaust

In the cold season, the car almost always smokes immediately after cranking. This is due to the fact that after the internal combustion engine cools down, condensation forms on the walls of the exhaust system. In cold weather, it can even freeze. Accordingly, when the internal combustion engine is started in the morning, the exhaust gases heat up this condensate and it turns into steam. Therefore, after starting, it takes several minutes for the condensate to evaporate from the exhaust system. The evaporation time will depend on the temperature outside, the volume of the internal combustion engine and the design of the exhaust system.

Please note that in fog and simply at high relative humidity, the exhaust gases from the pipe can be seen much better than in dry weather. Therefore, if you see that the car smokes white smoke in wet weather, but not in dry weather, most likely there is nothing to worry about. Unless there are other side effects, of course!

Malfunction of engine sensors

In injection ICEs, the electronic control unit of the ICE is responsible for the composition of the fuel mixture. It focuses on the readings of various sensors, including coolant temperature and intake air temperature sensors. Accordingly, at start-up it is quite possible to use a re-enriched fuel mixture, which will result in black smoke on a cold one. After the internal combustion engine warms up, the fuel mixture becomes leaner and everything falls into place!

Smoke after overhaul

After a major overhaul of the internal combustion engine, the car can also smoke for a while when it is cold. This behavior is associated with rubbing parts to each other.

Smokes on a cold diesel

Diesel engines have other reasons why they smoke when cold:

• nozzle failure. Incomplete combustion of fuel occurs. If at least one of the injectors does not work correctly, then the internal combustion engine starts to triple on a cold one. This is usually due to nozzle contamination or poor spray quality. As the engine warms up, the fuel mixture burns better, respectively, the engine starts to work better.
• crankcase ventilation clogged. For this reason, the diesel engine pulls up the oil, and it burns along with the fuel. As a result, black or dark blue smoke exits until the engine warms up sufficiently.
• Glow plugs. When the glow plug does not warm up correctly or does not work at all, then in the cylinders, when cold, the fuel may not ignite or the fuel may not burn out completely. As a result, black smoke appears in the exhaust. It will be present until the engine warms up sufficiently.
• fuel. Cold diesel smoke often has a black color, because even with a slight leak from the fuel injectors, it leads to such a phenomenon after starting the internal combustion engine.

What to do if the internal combustion engine smokes on a cold

If, after a long idle time, the machine smokes heavily, and after a while it stops, then the check must be performed according to the following algorithm:

1. Estimate the mileage of the car's internal combustion engine, and also remember what kind of oil is poured into the crankcase and how long ago it was changed. Accordingly, if the motor is worn out, and low-viscosity oil is poured there, then it is worth replacing it with a thicker one. Along with changing the engine oil, do not forget to change the oil filter, and it is advisable to take the original filter. If the oil is old and the internal combustion engine has high mileage, then it is advisable to flush the oil system before changing the oil.
2. The appearance of gray or black smoke on a cold internal combustion engine is an occasion to check the compression and the condition of the piston rings. If the compression is low, you need to find out the reason. In some cases, the cause can be eliminated by decarbonizing the rings. Along with decarbonization, it is also advisable to pour flushing oil into the internal combustion engine for cleaning purposes, and then change the oil to a new one, however, taking into account the viscosity according to the state of the internal combustion engine and its mileage. If there is a consistently high oil consumption, then it is worth changing the piston rings.
3. Check the condition of the oil seals. This is a fairly common reason why a car smokes when it is cold. For domestic cars, the approximate mileage before the next replacement of the caps is about 80 thousand kilometers. For foreign cars, taking into account the use of high-quality oil, this mileage can be two to three times more.
4. check the sensors using the diagnostic tool. If it shows an error in any of the nodes, then it is worth taking it more carefully and replacing it.
5. Check oil level and condition. An increase in volume or a change in color may indicate the presence of antifreeze. When the level of one of the fluids decreases, additional diagnostics must be performed - check the valve stem seals, rings, cylinder head gasket.

For owners of diesel engines, in addition to the above recommendations, it is also advisable to perform several additional procedures.

1. If, in addition to smoke, after starting the internal combustion engine, it also “troit”, then you need to check the condition of the fuel injectors. If a failed or contaminated nozzle is detected, it must first be cleaned, and if this does not help, replace it with a new one.
2. Check and, if necessary, clean the EGR.
3. Check the operation of the high pressure pump, the check valve and the fuel line as a whole for fuel leaks.

Hack and predictor Aviator

According to statistics, in about 90% of cases, the reason that the car smokes when it is cold is failed valve stem seals. Therefore, first of all, you need to check their condition. After that, you need to check the condition of the piston rings, the viscosity and the general condition of the oil. It will not be superfluous to diagnose the control unit for errors. As an option for the fastest diagnosis and finding out the origin of smoke, an ordinary sheet of white paper near the exhaust can become. By the traces and smell left on it, you can quickly determine what gets into the combustion chamber - liquid, fuel or oil.