Car Gas Tank Leak Repair Cost


One of the most aggravating and troublesome vehicle repair issues is a leak in the gas tank. This is something you will immediately notice as it happens because of the smell and stain in the driveway. It is also something that needs to be fixed quickly. 

The cost of the repair can vary depending on exactly what the problem is. A fuel tank replacement costs between $1,263 and $1,411. If the repair can be done with epoxy putty or welding the tank, your car gas tank lead repair cost could be under $200. 

Read on to find out more about fixing a fuel leak in your car.

Basics of a Fuel Tank’s Function

Many people think of a fuel tank as just holding gas but there is more to it than that. There is a release valve on the tank’s neck that allows fuel going into the tank to replace the air that’s inside. A full tank messages the pump to stop.

The fuel tank’s mechanical float adjusts to read the fuel level. 

Fuel tanks rarely need to be replaced unless you are doing restoration or if there is a puncture. Those who live in extreme environments that include things like humidity, cold, heat, sand, salt, or water may find their fuel tank may not have the life of others in more moderate areas. 

The tank may need to be replaced if some emission components like a vent and return lines fail. 

Read: Why Your Car Is Leaking Gas

Figure Out the Problem

The first thing to do if you see a puddle of fuel underneath the car is to figure out if it’s coming from the gas tank or the fuel line. A fuel line repair is little trouble to fix so it’s also less expensive. It can cost between $60 and $100 and can even be done yourself at home if you have a little advanced knowledge of mechanics. 

You can have a mechanic do an inspection to determine where the leak is originating. The mechanic will look at the ground to see if the drip is directly under the tank. They will then inspect the tank to confirm whether or not it’s leaking. 

The mechanic will then tell you if the tank can be repaired or if it needs to be replaced. Some repairs can be done with the tank remaining in the car while others will require the tank to be pulled. 

Pulling the tank for repair or replacement means the gas will need to be drained, fuel lines disconnected, removing holding straps, and removing the tank. Your mechanic should also take the time to inspect the fuel lines while they are disconnected to ensure they are in good order. 

Read: What Are the Symptoms of Fuel Tank Vent Blockage?

What Causes a Leak in the Gas Tank?

Two issues will cost a gas tank leak. The first is corrosion. This typically happens with older cars and could be more common in areas where there is a lot of snow and salt on the roads. Corrosion and rust can cause the seams to develop leaks or may cause a small leak in another spot on the tank. 

A corroded tank may be repaired or resealed or the problem may require a new tank.

The second issue you may face with a leaky gas tank is a puncture. Gas tanks are pretty durable but can be punctured if you run over a tree limb or some other object that hits it exactly in the right spot.

The entire tank would need to be replaced in this case.

Read: How to Start a Car With a Bad Fuel Pump

Ways to Fix a Leaky Tank

Those who want to fix a leaky gas tank themselves will have to put in some time to make sure it’s done correctly. You will need to mark any spots that appear to be leaking and drain the gas. 

Look for spots that have fuel stains surrounding them or that are wet with gas. Pay attention to the size of the leaks.  You can use epoxy for small holes and cracks. 

Holes that are larger than 1 inch in diameter will require welding. The tank will need to be removed to repair it. You will need to thoroughly wash the tank if you plan on welding the hole because gas residue can catch fire. 

The area will also need to be sanded.  You will also need to scrub it with a degreaser or rubbing alcohol.

If you are using epoxy, you must knead the material with a putty knife for about 5 minutes to activate it. Then roll it in your hands until it is a blended, consistent color. Use putty that matches the gas tank and use one that is specifically for a metal tank. 

Then, shape the putty over the leaky area. It should go over the hole enough to result in an airtight seal. Blend it into the tank. You can cover it with a fiberglass mesh path to reinforce it.

Let it dry for an hour.

Read: Bad Fuel Pressure Sensor Symptoms


What are the symptoms of a fuel tank lead?

The first symptom you will have about a fuel tank is you won’t get the fuel economy you always got before. The second symptom may be the check engine light lighting up the dash. 

Another symptom is gas ending up as a spot on the driveway and the smell of gas. There could also be trouble starting the car and it will idle rough. 

Can I drive with a fuel leak?

No, you shouldn’t drive with a fuel tank issue. This could be a safety issue as gasoline is flammable. It could also cause corrosion and debris to be flushed into the fuel delivery system, which can cause bigger issues later. 

How important is it to let a mechanic inspect your fuel tank?

It is important to take your vehicle for a fuel tank inspection immediately after you notice a leak. Leaking gas could result in a car fire or even an explosion. A mechanic may be able to repair without replacing the tank. 

Gas leaks only get worse with time so it’s best to get repairs done now. 

Can I use Flex Seal to fix a leaking gas tank?

No, you can’t use this product for a leaky gas tank. Flex Seal is not resistant to gas or oil. You also shouldn’t use Flex Seal Liquid on a gas tank. It could still ignite or leak after using this product. 

What kind of epoxy should I use?

You need an epoxy that can withstand 900 psi of pressure and 300-plus degrees. There are a couple of brands on the market that can do that and be used on metal tanks. 

Can I fix a leaky gas tank myself?

That depends on your experience. If the leaky area is small, you may be able to fix it with epoxy but larger leaks that require welding may be best suited for a mechanic unless you have welding equipment and the experience. 

How long does it take to fix a gas leak?

It depends on the problem. It can take 30 minutes or a few hours if they have to pull and repair the tank. It could take a couple of days if they have to order a new tank.

Why do I smell gas in my car?

It could be that fumes are entering your ventilation system. This could mean that you have a bad fuel pressure regulator. Other signs of this are lower fuel efficiency and a loss of engine power.

Read: How Often Should The Fuel Filter Be Changed?

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