What are the reasons for oil burning in the Peugeot 408 naturally aspirated engine?
3 Answers
The reasons for oil burning in the Peugeot 408 naturally aspirated engine are: 1. Abnormal oil consumption caused by damage to the exhaust valve; 2. Oil consumption due to aging of the engine valve seals and stuck piston rings. The solutions for oil burning in the Peugeot 408 naturally aspirated engine are: 1. Using higher viscosity oil to enhance the sealing between the engine pistons and cylinder walls; 2. Regularly checking the oil dipstick, changing the oil and oil filter periodically, and using genuine oil filter components. Taking the Peugeot 408 2020 360THP 10th Anniversary Premium Edition as an example: it is equipped with a 6-speed automatic transmission, with dimensions of 4750mm in length, 1820mm in width, and 1488mm in height, a wheelbase of 2730mm, and a body type of a 4-door, 5-seat sedan.
I have a Peugeot 408, the naturally aspirated version, and last year I noticed it was burning quite a bit of oil—losing half a liter every 1,000 kilometers. According to the mechanic's diagnosis, the main issue was worn piston rings. The piston rings seal the oil cylinder in the engine, and over time, the wear increases, allowing oil to leak into the combustion chamber and burn. My car is six years old and frequently used for long trips, so high mileage makes this more likely. Additionally, the seals on the valve stems may have aged—rubber hardens over time, letting oil seep in and burn. The signs of oil burning were obvious, like blue smoke from the exhaust pipe, especially during acceleration. This problem isn’t just a waste of money on oil; it also leads to increased carbon buildup in the engine, affecting performance and fuel efficiency. I ended up spending a few thousand to replace the piston rings to fix it. I recommend owners check the oil dipstick regularly, use synthetic oil to extend engine life, and not wait until it gets severe.
As a long-term driver with experience in the Peugeot 408's naturally aspirated engine, I've studied common causes of oil burning, including aging valve seals. These small rubber seals can harden and crack under high engine temperatures, allowing oil to leak into the cylinders and burn. Another major issue is piston ring wear leading to insufficient cylinder pressure, which draws oil up to be burned. I've also observed that PCV valve failure can sometimes be a contributing factor—a faulty valve increases crankcase pressure, forcing oil into the combustion chamber. The consequences of oil burning are significant: blue smoke from the exhaust, reduced power, increased fuel consumption, and over time, clogged catalytic converters that are more expensive to repair. Therefore, using high-quality oil is crucial, and regular maintenance, such as inspecting seals every 20,000 kilometers, can effectively prevent these issues.
