Why Do Some Cars Burn Engine Oil?
3 Answers
Here are the specific reasons for burning engine oil: 1. Worn valve seals: Valves are used to prevent oil from leaking into the combustion chamber, but over time, they can wear out or age. Severe wear can affect the sealing performance of the valves, making it easy for oil to burn. 2. Excessive piston clearance: When a car is used for a long time, carbon deposits from incomplete combustion can accumulate on the piston rings. If not cleaned for an extended period, this can enlarge the gap between the piston rings and the cylinder wall, allowing oil to enter the combustion chamber and cause oil burning. In severe cases, it can even lead to engine seizure. 3. Driving habits: Frequent rapid acceleration and prolonged high-speed driving can easily damage the lubricating oil film, leading to poor engine lubrication and wear on certain parts, which may also result in oil burning. 4. Excessive oil level: If the oil level is too high and exceeds the maximum mark, the excess oil can easily enter the combustion chamber (due to excessive internal pressure) and form gummy carbon deposits.
As someone who has been driving for nearly thirty years, I've seen quite a few cases of engine oil burning. This is usually related to engine aging, such as worn piston rings that can no longer seal properly, allowing oil to slip into the combustion chamber and burn. If the valve stem seals harden or crack, they can also leak oil. Long-term driving wear is the main cause, especially for older vehicles that have been driven extensively, as high temperatures and vibrations accelerate component fatigue. I recommend regularly checking the oil level with the dipstick and topping up with the appropriate oil if it's low. If left unrepaired, carbon buildup can become severe, spark plugs may get dirty, and the engine could overheat and seize, leading to expensive and troublesome repairs. Gentle driving without excessive throttle can reduce wear and extend the vehicle's lifespan. Make it a habit to check the oil regularly, as naturally as eating or drinking, to save both hassle and money.
After years of car repair experience, common causes of oil burning include excessive piston ring gaps, aging valve stem seals leaking oil, or severe engine cylinder wall wear. Imbalanced internal engine pressure can suck oil into the combustion chamber to be burned; design issues like certain cars' valve stem seals not being heat-resistant can lead to early failure; a clogged crankcase ventilation system also increases pressure causing oil leaks. For prevention, change high-quality oil and filters on schedule to reduce dust entering the engine and causing wear. If oil burning is detected, inspect promptly and perform compression tests to identify the fault. Neglecting repairs can lead to soaring fuel consumption, blue smoke from the exhaust, and a significant drop in engine efficiency. It's recommended to use oil with appropriate viscosity and maintain good ventilation - these small measures can prevent major overhauls.
