1. Eliminate whether there is engine oil in the exhaust pipe. If the valve oil seal leaks, it will leak the engine oil to the exhaust branch pipe, and then blue smoke will be generated at high temperature.
2. Excluding the above reasons, most of them are because the gap between the piston and the cylinder is too large, and the piston ring can't clean the oil, so it will emit blue smoke.
3. The sudden death of the piston ring will also produce blue smoke, because the piston ring expands internally. The engine after overhaul must be run-in according to the specifications. Remember to slam on the gas pedal.
Extended data:
Engine maintenance method:
1. Listen: Start the engine and listen to whether there is noise or abnormal sound when the engine is running at idle speed, medium speed and high speed.
Second, check:
1. Check the cylinder pressure or vacuum degree, remove the carbon deposit in the combustion chamber and grind the valve if necessary, adjust the valve foot clearance, and check whether the oil seal and crankshaft rear bearing leak oil. ?
2. Dismantle the carburetor and gasoline pump according to the situation, and test and adjust them on the test bench when necessary to make them meet the standards;
3. Check the bolts and nuts fastening the cylinder head, intake and exhaust manifolds and muffler, check the engine fixing parts, and check the connection and fastening between the flywheel housing and the cylinder block.
4. Check the working condition of the air compressor and the tightness of the pipeline, adjust the belt tightness, remove the oil, water and dirt in the air reservoir, and check the wiper and its air duct.
5. Check the fixing of radiator and cover, the working condition of water pump, whether there is water leakage, add grease to the feed pump shaft, and check the working efficiency of shutters.
Third, change:
1. Clean or replace coarse and fine oil filters, remove or replace oil pan, clean oil pump and oil filter screen, check or replace bearing bush, install oil pan and fasten it.
2. Replace the air filter and engine oil, and clean or replace the pipeline and connector of the gasoline filter.
Fourth, cleaning: develop a good habit of cleaning the engine compartment in spare time, and wipe off the dust, dead branches, leaves and fine powder on the surface of various parts inside the engine compartment with a rag, which can prevent spontaneous combustion, help the engine to dissipate heat better, and be cleaner and more beautiful, and look pleasing to the eye.