Symptoms of a Bad or Failing Gas Cap

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Cost of Replacing a Bad or Failing Gas Cap

Common signs include the cap not tightening properly, a fuel smell in the car, and the Check Engine Light coming on. Our certified technicians can come to you and diagnose the problem. You will receive a $30 credit towards any follow-up repairs that result from the diagnostic. Following are example prices for Gas Cap Replacement. Click on the button below to get an upfront quote for your car.

Cars Estimate Parts Cost Labor Cost Savings Average Dealer Price
2014 Hyundai Santa Fe XL $90 $20.13 $70.00 29% $127.63
2014 Fiat 500 $87 $17.17 $70.00 30% $124.67
2010 Chrysler 300 $81 $11.00 $70.00 31% $118.50
2009 Cadillac STS $91 $20.80 $70.00 29% $128.30
2004 Lexus GS300 $85 $15.47 $70.00 30% $122.97
2004 Porsche Cayenne $114 $44.40 $70.00 24% $151.90
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How to Diagnose a Bad or Failing Gas Cap?

gas cap

The gas cap, also known as the fuel filler cap, is a simple but important component that is found on the vast majority of road going cars and trucks. Their purpose is simple; to prevent dirt, debris, and dust from entering the gas tank, as well as providing a reliable seal. The cap also plays an important role in the operation of the vehicle’s evaporative emissions system, which is designed to capture and reuse fuel vapors from the gas tank that would otherwise be released into the atmosphere. Because the cap is frequently removed, every time fuel is added to the vehicle, it can wear out over time and will need to be replaced. Usually a bad or failing gas cap will produce a few symptoms that can alert the driver of a potential issue.

1. Cap does not tighten properly

One of the most common symptoms of an issue with the gas cap is a cap that does not tighten properly. Most gas caps are designed to click once they are tightened sufficiently. If the cap does not click, or clicks and then pops loose again then that may be a sign that it may need to be replaced.

2. Fuel smell from the vehicle

Another symptom of a possible issue with the fuel cap is a fuel smell from the vehicle. If the gas cap seal becomes damaged or worn it may cause fuel vapors from the gas tank to leak from the filler neck. This may result in a gasoline odor from the vehicle as a result of the escaping vapors.

3. Check Engine Light comes on

An illuminated Check Engine Light is another symptom of a potential issue with the vehicle’s gas cap. The gas cap is a part of the vehicle’s evaporative emissions system and can cause problems with the system if it has an issue. An improperly sealing fuel cap may cause an evap system leak, which will set off the Check Engine Light when the the computer detects the leak. The Check Engine Light can also be set off by a wide variety of other issue so having the computer scanned for trouble codes is highly recommended.

A bad or failing fuel cap will not necessarily cause major performance issues, but it can set off the Check Engine Light, which will prevent the vehicle from passing an emissions test. If you suspect that your gas cap may be having an issue, have the vehicle inspected by a professional technician, such as one from YourMechanic, to determine if the cap should be replaced.

Gas Cap
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Recent Gas Cap Replacement reviews

Excellent Rating


YourMechanic Gas Cap Replacement Service

Average Rating

4.5/5

Number of Reviews

27

Rating Summary
23
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Nicholas

8 years of experience
269 reviews
Nicholas
8 years of experience
He is a nice guy but I've had to have another mechanic come to look at the reason my truck is smoking ... there was 5 quarts of oil placed in my truck that only holds 3.5
2006 INFINITI FX35 - GAS CAP - HOUSTON, TEXAS

Yahshif

7 years of experience
128 reviews
Yahshif
7 years of experience
Yashif arrived early and finished quickly. He is extremely nice and professional. Great experience!
2003 MAZDA PROTEGE - GAS CAP - LOS ANGELES, CALIFORNIA

Duane

22 years of experience
323 reviews
Duane
22 years of experience
Showed up on time, very knowledgeable and professional
2009 NISSAN XTERRA - GAS CAP - SAN DIEGO, CALIFORNIA

Joel

18 years of experience
562 reviews
Joel
18 years of experience
Good Mechanic
2003 BUICK LESABRE - GAS CAP - JACKSONVILLE, FLORIDA

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