How many kilometers does Volvo 460 tractor adjust valve?

Excuse me, how many kilometers do you want to ask Volvo 460 tractor to adjust the valve? Adjust the valve every100000 km, and Volvo 460 tractor adjusts the valve every100000 km to compensate for the expansion of the valve after heating. When the automobile engine is working, the valve will expand due to the temperature rise. If there is no gap between the valve and its transmission parts in cold state or the gap is too small, the thermal expansion of the valve and its transmission parts will cause the valve to close loosely in hot state. It causes the engine to leak oil during the compression stroke and the power stroke, thus reducing the power and making it difficult to start in severe cases.