Sudden gas leak

Tiny
JIM SPECKMAN
  • MEMBER
  • 1995 GMC JIMMY
  • 6 CYL
  • 4WD
  • AUTOMATIC
  • 156,000 MILES
Drove 250 miles recently, pull out garage leaked gas on floor then stopped. I cannot find where it came from.
Sunday, May 29th, 2022 AT 12:54 PM

7 Replies

Tiny
KASEKENNY
  • MECHANIC
  • 18,907 POSTS
What is the general location of the leak on the vehicle? Is it located towards the front, under the engine, from the fuel tank?

Basically, once we get the general location then we can narrow down the possible causes.

However, the most likely cause of something like this is a rusted through fuel line. They are normally fine one day and then the next they leak fuel all over the floor. The reason is, once they let go, the pressure in the system opens them up and it dumps fuel.

The next likely cause of this is the filter connections.

https://www.2carpros.com/articles/how-to-change-a-fuel-filter

So, it is a good idea to check these connections for any fuel at all.

The best way to go about this is to dry the floor and then turn the key on so that you pressurize the pump. Then when you have a small puddle of fuel you will have an idea where this is coming from.

Then with the key off, start inspecting this general area for anything wet.

Clearly you don't want to lay on the ground under a fuel leak. So, try to get an idea first and then we can go from there.

Thanks
Was this
answer
helpful?
Yes
No
-1
Sunday, May 29th, 2022 AT 8:19 PM
Tiny
JIM SPECKMAN
  • MEMBER
  • 1 POST
Tried to answer, gas leaked good size puddle one time. Ran car leak stopped? Could this be an injector problem?
Was this
answer
helpful?
Yes
No
Monday, May 30th, 2022 AT 9:48 AM
Tiny
KASEKENNY
  • MECHANIC
  • 18,907 POSTS
Sorry, that was not helpful, but I am going to need more info to give a better idea as to what this could be.

It would not be an injector if you found the leak on the external of the vehicle. If an injector is leaking it will leak into the engine.

So, if the leak stopped, is it still leaking now or did it start again? If it is not still leaking, then I am not sure we are going to find it. However, a fuel leak normally doesn't leak and then stops so did this happen to leak right after you filled the fuel tank?

Are you sure it was fuel?

Where was the leak in relation to the vehicle?

Basically, I need a little more info to go on than what we have so far.

Thanks
Was this
answer
helpful?
Yes
No
Monday, May 30th, 2022 AT 4:34 PM
Tiny
JIM SPECKMAN
  • MEMBER
  • 1 POST
One time leak, good size under drivers on the floor. Nothing wet around fuel filter, did not leak again. Ran engine drove up and down long driveway, no leak?
Was this
answer
helpful?
Yes
No
Tuesday, May 31st, 2022 AT 10:16 AM
Tiny
KASEKENNY
  • MECHANIC
  • 18,907 POSTS
That is strange. The strange thing is that it only did it one time. Clearly if there is a fuel leak it will not correct itself. Once a fuel line starts leaking, I have not seen one stop as they are pressurized lines and once it breaks loose, it does not stop leaking.

The only thing that makes sense would be something was overfilled but that would be back by the tank and not under the floorboard.

Is there any chance that someone is playing a prank on you? Kids? Best friend that would think pouring fuel on the floor is funny? Clearly that is a long shot, but this is strange that it would only happen one time and with a leak that large that the engine started with no issues.

Did you touch it and confirm it was fuel by smelling it? Also, did you just find the leak, or did you see it dripping? Meaning did you see it when you pulled out of the garage while you were in the vehicle or did you see if before you got in?

The only reason I ask is that fuel evaporates pretty quickly so if it were there when you walked out but it was not dripping when you walked out then that would not add up either.

Just let me know more details about what happened when you find this. Was it first thing in the morning? Did you just drive the vehicle and come back out to find it?

As much detail that you can offer would be great. Thanks
Was this
answer
helpful?
Yes
No
Tuesday, May 31st, 2022 AT 5:31 PM
Tiny
JIM SPECKMAN
  • MEMBER
  • 1 POST
I took the vehicle out of house garage backed it back to the barn to check tire pressure one tire was low. Drove it back to the house 160 feet pulled into garage smelled gas checked it out saw puddle of gas under center of car. Backed the car out of garage still leaked small gas on drive. Took it to barn as reported jacked it up no leak no wet spot so far, no leak back in garage 2 days now no leak?
Was this
answer
helpful?
Yes
No
Wednesday, June 1st, 2022 AT 10:30 AM
Tiny
KASEKENNY
  • MECHANIC
  • 18,907 POSTS
Well, this is indeed an odd one or we are just missing something.

When you say it has been 2 days, have you been driving the vehicle like normal? Or has it just been sitting still and not running?

I think either way, the only way we are going to solve this is to get it leaking again.

So, what I would do is just turn the key to the on position so that the fuel pump primes the system and then start watching for a leak. Do not start the engine because if it starts leaking, we don't want to deal with hot exhaust or other possible fire causes.

Let me know what questions you have. Thanks
Was this
answer
helpful?
Yes
No
Wednesday, June 1st, 2022 AT 11:26 AM

Please login or register to post a reply.

Sponsored links