In recent years, the number of models with turbo engines has increased significantly in the automotive market. This is due to the fact that, in comparison with atmospheric engines, these units are more powerful and more efficient, but they also have disadvantages.
For example, these engines do not tolerate cold so well, especially when it comes to the extreme conditions of the Russian winter, when the air temperature is often dropped to -30 degrees Celsius and below.
During operation, hot exhaust gases pass through the “snail” of the turbine and spin it over ten thousand revolutions. As a result, it can heat up to 1,000 degrees, but at the same time it is very sensitive to sudden temperature changes. What do you need to know to avoid possible damage to the turbine during the cold season?
Warm up the engine before riding
If you own a turbo car, try to avoid cold starts as much as possible. The engine should be warmed up even if the car has stood in the cold for only a couple of hours, not to mention long overnight stops. Otherwise, the breakdown of the turbine will not be long in coming.
This is due to the fact that in the cold the rubbing parts of the “snail”, shafts, bearings and other units change in size, and during long (night) parking in the turbine, the oil also settles, which is why the working surfaces are deficient in lubricant at the start …
As a result, if you get behind the wheel of a “cold” car and immediately decide to load it to the fullest, turning the engine over 2,500 rpm and thereby activating the turbine, the latter will face extreme loads. It will heat up sharply, while such a rapid temperature change will entail an active thermal expansion of the above-mentioned details.
At such moments, the gaps between the rubbing surfaces can be reduced to several microns, which creates the risk of rupture of the oil film and, consequently, damage to the working parts.
To avoid oil starvation, drivers are advised to wait about 5 minutes after starting the engine. The turbine is not activated at idle speed, and this time is enough for the pump to pump oil to all units and assemblies, thereby providing high-quality lubrication of all working surfaces. However, even after that, it is not worth taking off “right off the bat”.
You can completely warm up the engine on the move in about 15 minutes, during which the engine must be kept within the range of 2,300 – 2,500 rpm. This will avoid the activation of the still cold turbine and bring it into working condition. Finally, it will be possible to add gas only when the temperature of the coolant reaches 90 degrees, and warm air is drawn from the stove.
End your trip the right way
In the cold season, the owners of turbocharged cars should not only start correctly, but also stop wisely. Before turning off the ignition, the engine should run for a couple of minutes at idle, which will contribute to a smoother cooling of the turbine due to the oil pumped to it.
If you just turn off the engine and leave the red-hot turbine in the cold, then sooner or later the latter will have dents and microcracks, which will lead to serious damage. Plus, with this approach, after the ignition is turned off, the stagnant oil coking occurs, as a result of which a hard carbon crust forms on the bearings and working surfaces, which again does not contribute to the normal operation of the turbine.
Signs of a faulty turbine
If you operate a car with a turbo engine without observing the above recommendations, then the turbine will soon become unusable. It is possible to determine the turbocharging on its last gasp by the extraneous hum and whistle that appears after starting the engine. Plus, the malfunction is indicated by increased oil consumption and blue smoke from the exhaust pipe.
These signs of an impending breakdown are due to the fact that the lubricating fluid enters the turbine through the play in the retaining rings and is pumped along with air into the exhaust system. However, as the engine warms up, extraneous noise and smoke from the pipes disappear, but the oil consumption does not decrease.
Excess lubricant penetrates into high temperature zones, which causes carbon deposits to form on the bearing shafts. The presence of the latter first leads to the appearance of an imbalance on the volute, and then to the gradual destruction of the bearings themselves and other parts.
In the event of a malfunction, the turbine is no longer able to provide the required level of air pressure, which leads to a significant decrease in engine power.