How to troubleshoot common cooling system problems(2)
1.3. Sudden engine overheating
① fault phenomenon: the water temperature meter pointer quickly indicate the position of 100 ℃; engine power dropped significantly; cold start, the water temperature rises rapidly and boiling, in the supplemental cooling water turned to normal.
② cause of failure: fan belt break or generator fixed pivot point loose displacement; thermostat main valve off; water pump shaft and impeller loose, cooling system serious leakage; cylinder gasket wash bad, the water pump and cylinder communication, high pressure airflow into the waterway.
③ diagnosis and exclusion: In the operation of the engine suddenly overheating, should pay attention to the charging indicator (ammeter) dynamics, if the engine speed is increased, the charging indicator light, or the ammeter shows no charging, indicating that the fan belt break caused by the water pump does not work. If the hand touch test radiator, engine, found that the engine temperature is high, the radiator temperature is low, indicating that the water pump shaft and blade loose. If the temperature rises rapidly when starting cold, cooling water boiling, mostly for the thermostat main valve off. If necessary, check whether the cylinder gasket is damaged.
④Applicable products: engine fan parts, cylinder head
2. Low engine temperature
①Failure phenomenon: temperature gauge indication value is lower than the normal working temperature of the engine, the engine work sluggish, muffler when there is a gun sound; fuel consumption increased.
② cause of failure: cold areas do not use insulation facilities; thermostat failure: too much engine lubricating oil.
③ diagnosis and exclusion: check the amount of engine lubricating oil, if too much, should be released, retain the appropriate amount of lubricant, and then check whether the thermostat failure, if the failure effect replacement.
④Applicable products: engine thermostat
Thermostat is like a valve that opens and closes according to the temperature of the engine. The thermostat isolates the engine from the radiator until a certain minimum temperature is reached. Without a thermostat, the engine will always dissipate heat to the radiator and will take longer to warm up.