Why Is The Sound Of 2004 Mitsubishi Shogun Diesel Approximate

My car is a 2004 Mitsubishi Shogun, Diesel with 160,000 km. I have a feeling that the engine noise is a bit harsh. Although the oil is regularly replaced, the filters are in good condition. Is it time to make or calibrate the settings? The car can travel a maximum of 120 km, is it normal? And Also Why did the black smoke come out while the car was traveling more than 80 km / h?

Thanks
Andre

Answer:

Using a car with a diesel engine does not mean that no maintenance is required. Like a petrol engine, a diesel car must be treated as a setting and so on, not just by replacing the oil or filter. The background noise of the motor is usually caused by a space of the valve whose space is already within the tolerance limit, which is restarted to overcome it.