4TNV98 ENGINE TURBO CHARGER 129908-18010 For YANMAR

Bearing damage

Phenomenon: the supercharger bearing is damaged, the engine power is reduced, the oil consumption is high, and black smoke is emitted. In serious cases, the supercharger cannot work.

reason:

1. Insufficient lubricating oil pressure and flow.

a. The lubricating oil supply of turbocharger journal and thrust bearing is insufficient;

b. Insufficient lubricating oil to keep the rotor journal and bearing floating;

c. The supercharger has been running at high speed, but the lubricating oil is not supplied in time.

2. Sundries or sediment enter the lubrication system.

3. The engine oil is oxidized and deteriorated.

a. The diesel engine oil is overheated, and too much gas flows between the piston and the cylinder wall;

b. The cooling water leaks into the engine oil;

c. Improper selection of engine oil and failure to change engine oil regularly as required.

Treatment method:

1. Check whether the lubricating oil pressure is normal and whether the oil quantity meets the requirements.

2. Replace the lubricating oil regularly according to the specified requirements and ensure that the lubricating oil is clean.

3. Lubricating oil shall be used in strict accordance with the specified requirements and shall not be mixed.

4. Avoid the engine from working under high temperature and keep the normal working temperature of the engine.

1. Clean the engine and replace the filter element. Drain the dirty oil, add 70% diesel oil and 30% engine oil to the engine, start the engine for 3-5min, clean the engine and oil passage, and then drain it. Add an appropriate amount of engine oil, run for 5-10min and then drain it. Replace the oil filter element and air filter element, and then filter and add clean lubricating oil to the full scale of the oil scale, so as to ensure that the engine lubricating oil and oil passage are clean.

2. Check the turbocharger. Check whether the model of the new turbocharger matches the engine. Rotate the turbocharger rotor by hand and it should run freely. If the impeller is sluggish or has the feeling of rubbing the shell, find out the reason and then install it.

3. Check whether there are sundries in the intake pipe of compressor and the exhaust pipe of engine in front of turbine to prevent the impeller from being damaged by sundries.

4. Check the oil inlet pipe and oil return pipe of the supercharger. The oil inlet and return pipes of the supercharger shall be clean, and the oil inlet and return pipes shall not be twisted and blocked. If a sealing gasket is used for the oil inlet and return port of the supercharger, check whether the gasket is corroded and deformed. The gasket cannot block the oil inlet and return port.

5. Prelubricate the supercharger. The supercharger is installed on the engine, and the oil pipe is not connected temporarily. First, add clean oil into the supercharger from the oil inlet of the supercharger, and rotate the rotor manually to fill the bearing of the supercharger with lubricating oil before connecting the oil pipe.

6. Test run. When starting the diesel engine, the oil inlet of the supercharger must show the oil pressure within 3-4s to prevent the bearing system of the supercharger from being damaged due to lack of lubricating oil. Run for 2min, check whether the rotor rotates smoothly without noise, and then stop the machine to observe whether the rotor can operate smoothly by inertia. Under normal conditions, the rotor will not stop until about half a minute later.

8. When the engine operates under load, the oil pressure must be between 196 and 392kpa to be safe. When the engine operates at idle speed, the oil pressure should not be lower than 70kpa.

9. The exhaust back pressure and the pressure drop of the air filter behind the turbine shall not exceed 4.9kpa. The air filter element shall be kept from being wet because the wet filter element will significantly increase the pressure drop.