What are the symptoms of a faulty crankcase ventilation valve?
2 Answers
The symptoms of a faulty crankcase ventilation valve are as follows: 1. Increased pressure in the crankcase leading to oil leakage from the seals. 2. Inability to expel exhaust gases from the crankcase, accelerating oil deterioration. 3. Premature introduction of crankcase pressure into the intake system, causing unstable engine idle. The reasons for crankcase ventilation are as follows: During engine operation, a portion of the combustible mixture and exhaust gases always escape past the piston rings into the crankcase. The condensation of escaped gasoline vapors in the crankcase will dilute the engine oil, degrading its performance. The exhaust gases contain water vapor and sulfur dioxide; water vapor condenses in the oil, forming foam and disrupting oil supply, a phenomenon particularly severe in winter.
I've been driving that old car, and suddenly the engine started idling unevenly, going up and down like it's dancing, accompanied by some shaking and occasional stalling. Every time after starting, the car lacks power when accelerating, especially noticeable when climbing hills, and the fuel consumption has also increased significantly. Once after parking, I noticed oil leakage under the hood, all wet. Later, the mechanic said it's most likely the crankcase ventilation valve that's broken. That thing is responsible for regulating internal pressure, and once it fails, it's easy for oil to accumulate and cause air blockages, leading to foul emissions and black smoke. If not replaced in time, the overall lifespan of the engine will be shortened, so now I check it regularly.
