Motor Vehicle Maintenance & Repair Stack Exchange is a question and answer site for mechanics and DIY enthusiast owners of cars, trucks, and motorcycles. Join them; it only takes a minute:

Sign up
Here's how it works:
  1. Anybody can ask a question
  2. Anybody can answer
  3. The best answers are voted up and rise to the top

I dented the tray under my gas tank, reducing my capacity by about a gallon. It's a wide dent; there's no damage to the plastic. I'd like to drop the tank and pound out the dent in the aluminum tray. Draining the gas, removing the fuel lines, fill hose, electrical running to the gas pump, and the straps seems pretty straightforward.

What I don't know is:

  • When I hook everything back up, will the car start right up again? I don't exactly know how the car will handle any air that's entered the lines, or will the automatic choke and gas pump take care of everything?

I've heard some cars, after running out of gas, need to be filled to a certain level before they'll attempt to start again. Should I have a small tank or a 5-6 gallon tank standing by? What little I drain out will probably not be going back into the tank.

It's a 2007 Pontiac G6 -- does anybody know if the tank is anchored to the bottom of the chassis by anything other than the straps? I've seen some cars have a clip or bolt under the seat in the back.


share|improve this question
up vote 6 down vote accepted

The fuel pump combined with the fuel pressure regulator should take care of any air in the lines. If you don't like the idea of cranking the car continuously until it starts (it would take 3 cycles or so), then turn the key into the "on" position without cranking it. This causes the fuel pump to run, because it primes the fuel system in anticipation of cranking. You may hear the pump running. Turn it off and on several times, and the fuel pressure regulator should allow the fuel to reach the injectors. It should crank up on the first start at this point.

As long as there is enough fuel to surround the fuel pump, the pump will be able to pick it up and send it forward. On most cars 2-3 gallons should be fine.

You really need a full repair manual for this specific car to answer the rest. There may be additional anchors or special considerations in how to lower the tank to avoid breaking lines that can't be seen above the tank.

Be sure to watch out for static as you work around all of those fumes.

share|improve this answer
Thanks, this is exactly what I was looking for. – Cᴏʀʏ Mar 8 '11 at 19:58

Your Answer


By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.