What are the common problems with the B12 engine?

[LailaMarie]

The common problems with the B12 engine include: 1. Unstable idle speed, fluctuating between high and low; 2. Lack of power during acceleration. The car engine is the device that provides power to the vehicle, acting as the heart of the car, determining its power, fuel efficiency, stability, and environmental performance. Depending on the power source, car engines can be classified into diesel engines, gasoline engines, electric motors for electric vehicles, and hybrid systems. Common gasoline and diesel engines are both types of reciprocating piston internal combustion engines, converting the chemical energy of fuel into the mechanical energy of piston movement to deliver power. Gasoline engines are characterized by high rotational speed, low weight, low noise, and easy starting; diesel engines feature high compression ratios, superior thermal efficiency, excellent fuel economy, and emission performance.

[IsabelAnn]

I've driven several cars equipped with the B12 engine, and the most common issue I've encountered is oil consumption. After running about a thousand kilometers, the oil dipstick shows a significant drop, mostly due to the less-than-ideal design of the oil-gas separator, which doesn't fully separate the oil vapor. Additionally, during cold starts, the timing chain often makes a clunking sound—this needs to be replaced promptly to avoid valve damage. The valve cover gasket also tends to leak oil frequently, as the plastic components are prone to deformation under high temperatures. Idle vibration is another annoyance, usually requiring carbon deposit cleaning or spark plug replacement. Overall, this engine delivers good power, but you need to check the oil level regularly and perform maintenance ahead of schedule to ensure longevity.

[LeEmilia]

Having worked on numerous B12 engines, I'll highlight some common issues. Firstly, the timing chain system has a high failure rate, with plastic guide rails prone to aging and cracking, resulting in rattling noises during cold starts. Secondly, the oil separator often fails, leading to excessive oil consumption - keeping spare oil in the trunk is advisable. Thirdly, valve cover gasket leaks are prevalent, especially in vehicles over 5-6 years old, as the rubber seals typically deform. A frequently overlooked issue is the unstable coolant temperature sensor, which tends to generate false trouble codes. Regular endoscope inspections for valve carbon buildup are recommended for early detection and treatment.

[SanBrantley]

Owners who have used the B12 engine for a long time can relate—after 50,000 kilometers, minor issues start to surface. The most common problem is abnormal oil consumption, especially when accelerating hard, with blue smoke appearing in the exhaust. Oil leaks from the valve cover are another hurdle, but switching to an aluminum alloy cover can make a big difference. Timing chain system failures typically strike around 100,000 kilometers, and the rattling noise during cold starts is particularly frustrating. Some electronic components are also troublesome, like the camshaft position sensor, which tends to fail and cause unstable idling. Pay extra attention to these points during routine maintenance, and don’t hesitate to replace critical parts when needed.

[VonSpencer]

Common issues with the B12 engine are concentrated in these design flaws: The timing chain uses an open guide rail, where plastic components become brittle and prone to breakage under high temperatures. The valve cover is made of composite material, leading to poor sealing due to thermal expansion and contraction. The labyrinth structure of the oil-gas separator is ineffective, allowing oil vapor to directly enter the combustion chamber. The crankcase ventilation system is poorly designed and prone to clogging. These problems are not obvious in new vehicles but tend to emerge collectively after 70,000 to 80,000 kilometers. When addressing these issues, remember to replace parts with improved versions, which are more durable than the original factory components. Regular carbon deposit cleaning can delay the onset of symptoms.