What are the reasons for oil burning in the Audi A6L 2.0T?

[DeGideon]

There are many factors that affect oil burning, including fuel quality, driving conditions, driving habits, maintenance habits, etc. The above reasons can exacerbate oil consumption and lead to oil burning. The effects of oil burning are as follows: Carbon deposits form in the combustion chamber, causing the compression rings of the piston rings to stick and resulting in poor sealing; sludge forms in the lubrication system, blocking the oil return holes of the oil control rings and weakening their oil-scraping performance; wear occurs between the piston and cylinder wall; the valve seals corrode and age, leading to sealing failure. The causes of oil burning can be classified into cold-engine oil burning and hot-engine oil burning. Below are explanations of cold-engine and hot-engine oil burning. Cold-engine oil burning: When the car's temperature has not fully warmed up, the engine exhaust emits a lot of blue smoke, but it returns to normal after the engine warms up. This phenomenon is caused by aging valve stem seals. Due to the drop in temperature, the rubber material of the valve stem seals becomes stiff, preventing complete sealing. Oil leaks from the valves into the combustion chamber, burns, and produces the above phenomenon. Hot-engine oil burning: After the car reaches normal operating temperature, the exhaust pipe still emits blue smoke, indicating poor sealing of the piston rings. Due to poor piston ring sealing, oil is forced by the oil pump through the leaking piston rings into the combustion chamber, where it burns, resulting in blue smoke from the exhaust pipe. Several factors can cause this phenomenon, such as material aging, carbon deposits causing sticking, excessive cylinder liner wear, etc.