PCV Valves

The Positive Crankcase Ventilation (PCV) valve hose transfers excess gasses from the crankcase to the PCV valve. From there, it is added to the intake manifold and used by the engine. If the PCV valve hose breaks, the gas will not be transferred back into the engine, and your vehicle will be less efficient and have increased emissions. There are a few symptoms to watch out for when you have a bad or failing PCV valve hose / diaphragm.

1. Poor fuel economy

If the PCV valve hose is clogged or has a leak, it may cause poor fuel economy. This is because the vacuum on the intake side of the cylinder head will not be able to properly signal the correct amount of fuel that needs to be fed into the engine and can result in a lean or rich engine condition.

2. Check Engine Light comes on

The Check Engine Light may come on for a variety of reasons, and one of them is a failing PCV valve hose. This is because the PCV valve hose works directly with your engine to ensure everything is working properly.

3. Misfiring while idling

Another symptom of a bad or failing PCV valve hose is your vehicle will misfire while it is idling. This can be from a loss of vacuum due to the hose not working properly because of a leak, the hose being pinched, or becoming clogged from buildup over time. A misfire will sound like the engine has a vibration to it is a sign it is not running properly.

4. Noise from the engine

If you hear a hissing sound from the engine, it is time to get your vehicle looked at. The PCV valve hose may have a leak in it, which is causing the hissing sound. Leaving this for too long can cause misfires, rough running, vacuum leaks and you will have a more extensive repair on your hands.

5. White smoke out the exhaust

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