What Causes the Increase in Engine Oil in Dongfeng Nissan X-Trail?
4 Answers
Engine oil increase occurs because the engine injects a large amount of gasoline during startup. Sometimes, due to excessive injection and incomplete combustion, the high pressure on the cylinder walls forces gasoline into the engine oil. Normally, gasoline evaporates once the engine reaches operating temperature. However, frequent cold starts and cold weather in northern regions can prevent the engine oil from warming up sufficiently, making it difficult for the gasoline to evaporate, leading to a continuous increase in engine oil. Here is a related introduction to engine oil increase: 1. Hazards: When the engine oil increases to a certain extent and exceeds the upper limit on the dipstick, some oil may enter the combustion chamber and participate in combustion, resulting in oil burning. Oil burning can have serious consequences, such as failure of the catalytic converter, rapid damage to the vehicle's oxygen sensors, increased carbon deposits in the combustion chamber, unstable idling, reduced acceleration power, increased fuel consumption, and excessive exhaust emissions. 2. Solutions: In low-temperature environments, perform actions like warming up the engine or driving on highways to allow the engine to reach sufficient temperature conditions, enabling the gasoline or moisture mixed into the oil to evaporate. If there is a slight increase in engine oil, try raising the engine temperature to resolve the issue. However, if the oil increase phenomenon does not improve, it is best to visit a 4S shop or a repair shop for a thorough professional inspection to identify the source of the fault, solve the oil increase problem, and ensure the engine oil can better protect the engine, creating a favorable working environment for engine operation.
I have repaired many X-Trail vehicles and found that the most common cause of increased engine oil is gasoline mixing into the oil, especially in direct-injection engines during cold starts and short trips, where unburned fuel can seep into the oil pan. Another key issue is the design flaw in the crankcase ventilation system, which causes excess gases to condense into water or oil droplets, raising the oil level. For example, the 2.0-liter engine in Dongfeng Nissan X-Trail may have this defect, and there were recall cases around 2018 for certain models. If you smell gasoline or notice higher-than-normal oil levels during an oil check, it's best to visit a dealership for diagnosis as soon as possible. Otherwise, prolonged use can wear out engine bearings and reduce service life. Regularly checking oil levels during routine maintenance is a good habit to prevent major issues.
I've been driving a Nissan X-Trail for three years. Last winter, I suddenly noticed that the oil dipstick showed a higher oil level, and the oil had a distinct gasoline smell—a classic case of oil dilution. Experts say the cause is fuel dilution, where unburned gasoline from the engine seeps into the oil, especially during short trips in cold weather. From my personal experience, I went to the dealership to have the oil changed and the relevant components cleaned. After they adjusted the crankcase ventilation system, the issue was resolved. Now, I always avoid high-speed driving immediately after a cold start and let the engine warm up properly, and the oil problem hasn't recurred. I recommend X-Trail owners check their oil levels every few months and address any issues promptly if they arise.
I think the oil dilution issue in the X-Trail is likely caused by low-speed engine operation. When the vehicle frequently starts and stops in urban traffic, unburned fuel can leak into the oil pan. Combined with a clogged ventilation system and accumulated condensate, the oil level naturally rises sharply. During inspection, check if the oil appears diluted or has an unusual odor. Early intervention is key—replacing the affected components can restore normal operation.
