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.
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. If you suspect a PCV valve hose is the reason you have been getting poor fuel economy, contact the professionals at YourMechanic to have your PCV valve hose replaced.
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. The mechanics at YourMechanic can diagnose the exact reason the Check Engine Light is on, whether it is the PCV valve hose, the PCV valve, or a combination of parts.
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.
YourMechanic makes getting repairs to your PCV valve hose easy by coming to your home or office to diagnose or fix issues. You can book a service online 24/7. YourMechanic’s qualified Technicians are also available for any questions that may arise.
This article originally appeared on YourMechanic.com as Symptoms of a Bad or Failing PCV Valve Hose and was authored by Spencer Clayton.