Fuel Tank Noise

We recently had our fuel pump replaced on a 98 Tahoe. Now, after it has been driven, is turned off, sits for about 3-5 minutes, the gas tank makes a noise like it is expanding or contracting - a "thunk" noise.

Any ideas out there. Is the gas cap bad, allowing air in?
Thanx.

I have a 2000 Tahoe and it is doing the exact same thing....has ever since I bought it! I am VERY interested to know the cause/solution. You are the first one I've seen with this problem too.



We recently had our fuel pump replaced on a 98 Tahoe. Now, after it has been driven, is turned off, sits for about 3-5 minutes, the gas tank makes a noise like it is expanding or contracting - a "thunk" noise.

Any ideas out there. Is the gas cap bad, allowing air in?
Thanx.

I have a 99, and have had this problem. At 30,000 miles I had it in the dealer for this problem, and they said they could'nt find a problem. That was 60,000 miles ago. It seems to have dimminished.

OMG! I thought I was going nuts! I seem to be the only one that ever heres it make the noise. I'd be very interested to here what is causing this.

one of the tahoe issue classics, everyone has this problem it seems, the pump is in-tank and when the tank becomes more and more empty the space allows for the pump to make more noise, modern engines like the vortec have to sustain fuel pressure around 60 psi so pumps have to work harder, noise means operation, be worried when you dont hear your pump ;P

I have a 97 n I hear a hmmmmmmin sound, its like its whinin. is that good or bad?

I have that same problem, kinda like a wheezing sound. It even stays on for about 2 seconds after turning off the vehicle. I was going to replace my fuel pump. I thought once it starts making noise, that means its fixing to go out.

Yup, that noise is a bad sign. My fuel pump just went out on me, and now its going to cost between 259-279. Good thing I have under quarter of a tank.

You doin it your self? Is that the price of the pump?

yeah, fixing to install it now. I found one at pep boys for $169, came out around $218. I have the hoses disconnected, skid plate off, and the tank loose. Im fixing to go drop it right now. im going to use a jack to help hold it up.