What is the rubber hose on the engine called?
1 Answers
The rubber hose on the engine is called the crankcase forced ventilation tube. The purpose of crankcase forced ventilation is to maintain the pressure balance of the crankcase inside the engine body, preventing damage to sealing parts due to excessive or insufficient pressure. When the engine is idling or operating at low speed and low load, the crankcase is in a state of significant negative pressure. This condition can cause a large amount of engine oil to enter the intake system along with blow-by gases and participate in combustion, leading to oil burning and severely affecting the engine's performance and emissions. Therefore, the crankcase must be forcibly ventilated. When the pressure inside the crankcase increases, the crankcase is ventilated through the exhaust valve or oil-gas separator, keeping the pressure fluctuations within a reasonable range. Inspection method for the forced crankcase ventilation system: Remove the ventilation hose from the forced crankcase ventilation valve, remove the crankcase ventilation valve from the rocker arm cover, reconnect the crankcase ventilation valve to the removed ventilation hose, start the engine, and let it idle. Place a finger over the opening of the crankcase ventilation valve to feel and confirm whether the intake manifold reaches a vacuum (whether the finger is attracted). At this time, the plunger of the crankcase ventilation valve will move back and forth. If no vacuum is felt, clean or replace the crankcase ventilation valve.
