Symptoms of a Bad or Failing Positive Crankcase Ventilation (PCV) Valve

Schedule Check Engine Light is on Inspection
Service Area

$79.99 - $89.99

Price range for all vehicles
Average rating from 4,810 customers who received a Check Engine Light is on Inspection.

The positive crankcase ventilation (PCV) valve works to evacuate gas from the crankcase of the engine. The PCV valve directs these gases back into the combustion chambers via the intake manifold. This plays a large role in engine efficiency, improving emissions and the overall operation of your vehicle. A bad PCV valve will affect the performance of your vehicle, so there are a few signs to watch out for before the valve completely fails:

1. Excessive oil consumption and leak

A bad PCV valve may have a leak, which will cause excessive oil consumption. In addition, you may also notice oil leaking through the seals and dripping on to the floor of your garage. This is because the pressure in the crankcase may increase when the PCV valve fails, so the oil is pushed out through the seals and gaskets since there's no other way for the pressure to be released. The leak will cause your vehicle to burn oil and leak oil beneath your vehicle. If you notice either of these, consult a professional mechanic to have your PCV valve replaced.

2. Contaminated filter

A filter called a breather element may become contaminated with hydrocarbons and oil once the PCV valve starts failing. This is due to the increased pressure building up in the crankcase, which pushes water vapor through the breather element. The water gets mixed with the gas, which causes the buildup and can increase fuel consumption in your vehicle. One way to check this part is to physically inspect the filter for buildup. Another way is to measure the gas mileage on your vehicle. If it starts to go down seemingly without reason, the PCV valve may be going bad.

2. Overall poor performance

As the PCV valve starts going bad, the performance of your vehicle will get worse. This can be exhibited by a buildup of pressure in the exhaust or the engine could stall out. The bad PCV valve may not close all the way, so oxygen may get into the combustion chamber. When this happens, the fuel and air mixture is diluted causing your vehicle to run poorly and lean out.

If you notice your vehicle is leaking oil, consuming large amounts of oil, you have a contaminated filter, or the car is not working like it should, have the PCV valve looked at and replaced. This will keep your vehicle running smoothly and keep your fuel economy where it should be. YourMechanic makes getting repairs to your positive crankcase ventilation valve easy by coming to your location to diagnose or fix issues. YourMechanic’s experienced technicians are also available for any questions that may arise. You can book a service online 24/7.


Next Step

Schedule Check Engine Light is on Inspection

The most popular service booked by readers of this article is Check Engine Light is on Inspection. Yourmechanic’s technicians bring the dealership to you by performing this job at your home or office 7 days a week between 7AM-9PM. We currently cover over 10k cities and have 100k+ 5-star reviews... LEARN MORE

SEE PRICING & SCHEDULING

The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details

Recent Check Engine Light is on Inspection reviews

Excellent Rating


YourMechanic Check Engine Light is on Inspection Service

Average Rating

4.8/5

Number of Reviews

4,810

Rating Summary
4,424
187
47
28
124
4,424
187
47
28
124

Joel

19 years of experience
741 reviews
Joel
19 years of experience
Acura RL - Check Engine Light is on - Jacksonville, Florida
very knowledgeable and precise. able to fix electrical issues in my car. Right on time for the appointment.
Toyota Highlander - Check Engine Light is on - Jacksonville, Florida
Joel was very efficient with inspecting my vehicle. He told the issues with the vehicle and gave great advice on what needed to be done for the repairs. I will definitely use this service again.

Matthew

31 years of experience
639 reviews
Matthew
31 years of experience
Jeep Patriot - Check Engine Light is on - Norfolk, Virginia
Matthew was on time which was a relief, he is very knowledgeable and was easy to understand what was wrong and what was being done. I am recommending to friends and family due to the great experience Matthew gave me. Extremely professional 10/10
Mercedes-Benz E320 - Check Engine Light is on - Williamsburg, Virginia
MATT WAS AMAZING! HE EXPLAINTED EVERYTHING SO WELL! HIS EXPERTISE AS A MECHANIC IS EVIDENT AND I HIGHLY RECOMMEND HIM.

Michael

14 years of experience
501 reviews
Michael
14 years of experience
Ford Mustang - Check Engine Light is on - Decatur, Georgia
Michael was extremely courteous and knowledgable, he diagnosed and solved my issue in record time. Will definitely look to him next time I'm in need of a mechanic!
Chrysler Sebring - Check Engine Light is on - Atlanta, Georgia
Michael arrived on time and was efficient. He also explained the issues my car was having in an understandable way, and gave me good advice on what to do moving forward with the repairs.

Christopher

15 years of experience
41 reviews
Christopher
15 years of experience
Honda Accord - Check Engine Light is on - Fairburn, Georgia
Christopher was excellent! He explained everything in detail to make sure I understood. He was professional and provided me with the next course of actions to resolve my care issues. I'm glad he was sent to service my car.

Need Help With Your Car?

Our certified mobile mechanics make house calls in over 2,000 U.S. cities. Fast, free online quotes for your car repair.

GET A QUOTE