Hissing noise from under car

[usranger1]

When I start my car I hear a hissing sound coming from underneath.the sound is coming from the back of the car.
I believe from near the gas tank. Does anyone have any advise
on what it could be. I have a 99 Grand Am GT 3.4

[sunrunner_pei]

Originally posted by usranger1
When I start my car I hear a hissing sound coming from underneath.the sound is coming from the back of the car.
I believe from near the gas tank. Does anyone have any advise
on what it could be. I have a 99 Grand Am GT 3.4

Quite simple. :) That's your fuel pump. Perfectly normal.

[usranger1]

It sounds like a air leak it does not sound like the
fuel pump.

[99GrandAMSE]

Originally posted by usranger1
It sounds like a air leak it does not sound like the
fuel pump.

Do you hear it for a couple seconds when you turn the car to the ON position without starting the car? If so, then it is definately your fuel pump :)

[usranger1]

No it is a constant hiss. it does not stop.

[pittviper]

sounds like it could be a small exhaust leak .
just jack the back of your car up and start it then crawl under it and run your hand along the exhaust pipe and around the muffler to see if you feel any air comming out from it .
or you take it to a mechanic you trust and have him check it for you .

[SC/TGrandAm]

its normal all the GT's do it. Its the fuel pump.

[99GrandAMSE]

Originally posted by usranger1
No it is a constant hiss. it does not stop.

I doesn't stop even if you leave the car in the ON position without starting it?? I still think you are hearing the fuel pump ... but like another member said, it could be a small exhaust leak too :(

[SC/TGrandAm]

mines a constant hiss too both my GT's did it. Its normal, but if you think its an exhaust leak take it to the dealer if you feel the need.

[ramairgt1]

my car does it as well, its the fuel pump :)

[Baggs927]

I have a 97 Grand Am and i have been stumped on this for a while. My car when it heats up makes a hissing/high humming sound which seems to be coming from the rear mid driver side of my car. Also my car runs rich and leaks coolant. I have no idea what the problem is. I have replaced a O2 sensor, thermastat, PCV Valve, and Fuel Filter. Nothing seems to help ANY of my problems.

[carlover626]

First, my GT is always hissing from the back - it's the fuel pump. I can hear the first hiss in the morning (Cold start) then if I start it and get out the noise is still there, I can even hear it in a drive thru.
Baggs927
Where are leaking coolant, or is it just "dissappearing"?
Have you inspected your plugs/wires?

[Baggs927]

The coolant seems to be coming from directly underneath my coolant resivoir. It ends up as a puddle right underneath my car next to the front passenger tire. My noise is more of a humming coming from the middle underneath the car, and it only starts after the car heats up to normal temp.

[RocketFast321]

Sounds like your water pump. Very easy fix.

as for the hiss, bad cat???????? I dunno

[Baggs927]

How much does that cost do do it yourself?

[RocketFast321]

$24 at most

[RocketMan]

Originally posted by pittviper
sounds like it could be a small exhaust leak .
just jack the back of your car up and start it then crawl under it and run your hand along the exhaust pipe and around the muffler to see if you feel any air comming out from it .
or you take it to a mechanic you trust and have him check it for you .


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