Introduction to the causes of oil leakage from the diesel heater exhaust pipe: Check for external oil leaks: Pay special attention to whether there is oil leakage at the front and rear crankshaft oil seals. A cracked, damaged, or aged front crankshaft oil seal, or wear on the contact surface between the crankshaft pulley and the oil seal, can cause oil leakage at the front of the crankshaft. A cracked or damaged rear crankshaft oil seal, or an excessively small oil return hole in the rear main bearing cap, which obstructs oil return, can cause oil leakage at the rear of the crankshaft. Additionally, check for oil leakage at the rear camshaft oil seal. If the oil seal is aged or cracked and leaking, it should be replaced promptly. Furthermore, inspect all components of the engine lubrication system for any external leaks. Oil leakage at the front and rear oil seals: If oil is seeping from multiple locations, such as the front and rear cylinder head covers, front and rear valve lifter chambers, oil filter, oil pan gasket, etc., but no obvious leak source can be found, check the crankcase ventilation system. Clean the crankcase ventilation pipes, especially inspecting whether the PCV valve is malfunctioning due to carbon buildup or sticking. Poor crankcase ventilation can significantly increase pressure inside the crankcase, leading to oil seepage from multiple locations.
