Guys I may be over reacting to this, but I will not take my chances. I noticed a slight hizzing sound coming from the fuel tank area, left side(driver side) close to were the fuel lines meet the fuel tank. Is this simply the sound made by the fuel being sucked away from the fuel tank or should I take it to the dealer? Can some of you guys confirm this and see if your outies make this noise also, you will have to pay attention and get close to the tank, I dint notice ituntill I changed my oil and heard it, now I'm paranoid and hear it all the time.

 

I'm no expert but it's common to hear a buzzing noises from fuel pumps in hot weather

 

You had the thing running when you did the oil change? I know you didn't just sounds like thats how you said it. If the sound was coming from the gas tank area when you had the outie running and it has been hot lately maybe its a vent bleeding off. The tank could be heating up from the exhaust running past it. Look for vents and see if it does the same sound when it cools down at night and the motor has cooled off.

 

I'm with Anto on this one - likely venting. Temperature and atmospheric pressure changes impact it the most. Assuming there are some breather hoses coming off the tank somewhere(and are readily available for inspection), make sure no road debris is clogging them.

 

There are no vents to the outside world from the fuel tank. The vent system, called EVAP (for evaporative emissions) is computer controlled througha series of valves through a charcoal canister that is not in the tank. This is because evaporative emissions have the potential to cause more greenhouse pollution than the emissions coming out of the tailpipe on a properly running new car. If the system is leaking you WILL get a check engine light. The same code will set if you leave your gas cap loose. P0455, P0456 or P0457 depending on the size of the leak. I would say though, if you are worried about it, take it in, I assume you are under warranty still. Why not put your mind at ease.

 

I ran the car this morning to see if it did it again, and yes it did. The noise is not constant though, its more of an on off on on off on off pattern to it. By the way, yes I'm still under warranti, but my mitsu dealer only has onetech, andits a pain to get a hold of him everytime not to mention he's an idiot( had thebearings replaced with the exact same ones that were causing the noise) soI wouldnt want to make an unessesary trip, if this is abnormal however, I'm willing to drive to another dealer(2 hrs away). So, has anyone actually ran theyr cars up and see if theirs make the same noise from there? I think I started to notice it once the car was warmed up. It is really not that notisable unlessyou get down to the tank(driver side)and pay attention,so it may be normal,if it is and you guys can confirm byproving it with your 07 outies, you would save me a lot of headaches amd time, so thank you in advance.

*EDIT* oh by the way I looked for a vent hose or any vents and could not see any? this maybe either normal suction noise or a bad line inside the tank? who knows?.

 

Id put money on it being the fuel pump. The pump would likely cycle on off at idle. I had a toyota truck that I had to replace the fuel pump so instead of dropping the tank I put an aftermarket inline. It was very noisy it whirred and made a fluid moving sound that you could hearfrom several feet away,it was a very reputable brand of pump so I know it was just the nature of the beast. I wonder if the outies are blessed with an outside fuel pump instead of in the tank, I doubt it though.

 

 

So thats more than likely what I'm hearing? the "pressure relieve valve". If so, why do I hear it almost right after initial start up, even when the engine has sat all night?

 

The pressure relief is emergency situation only. Should not be happening unless fuel tank pressure is WAY too high, and the EVAP system is not working. And, the fuel pump won't cycle on and off. It runs constant. I havn't noticed this type of noise from mine, so I can't say what it is for certain.