Symptoms of a failing PCV system:
* Oil leaks: A faulty PCV valve or cracked hose can lead to oil leaks, especially around the valve cover and intake manifold. This is a very common symptom.
* Excessive crankcase pressure: This can cause oil leaks, as mentioned above, but also can blow seals and gaskets, leading to further problems. You might notice excessive oil buildup in the air intake system.
* Rough idle or stalling: A malfunctioning PCV system can disrupt the air/fuel mixture, leading to a rough idle or even stalling, especially at low RPMs.
* Reduced engine performance: The disrupted air/fuel mixture can also cause a noticeable decrease in engine power and acceleration.
* Increased emissions: The PCV system is crucial for removing combustion byproducts from the crankcase. A failure can lead to higher emissions, potentially resulting in a failed emissions test.
* Oil sludge buildup: Poor PCV function can lead to the accumulation of sludge in the engine oil, shortening engine life.
* Check Engine Light (CEL): While not always the case, a severely malfunctioning PCV system can trigger the CEL. The code will often point to a related issue (e.g., vacuum leak).
Common causes of PCV system problems:
* Clogged PCV valve: The valve itself can become clogged with oil and sludge, preventing proper ventilation. This is the most frequent problem.
* Cracked or damaged PCV hoses: The hoses connecting the valve to the intake manifold and valve cover can crack or become disconnected due to age, heat, or wear.
* Vacuum leaks: Leaks in the intake manifold or vacuum lines can affect the PCV system's function.
* Blocked breather tube/vent: The tube that vents crankcase gases might be clogged with oil and debris.
* Clogged intake manifold: In severe cases, oil residue from a faulty PCV system can clog the intake manifold.
Troubleshooting and Repair:
Diagnosing a PCV problem usually starts with a visual inspection of the hoses and valve for cracks, leaks, or blockages. The PCV valve itself is relatively inexpensive and easy to replace. A mechanic can perform a pressure test on the crankcase to determine if excessive pressure exists, indicating a PCV system problem.
Important Note: Ignoring PCV system issues can lead to significant and costly engine damage. If you suspect a problem, it's best to address it promptly. A simple replacement of the PCV valve and inspection of hoses is often a cost-effective preventative measure.
