Popping sound, gas cap area?
Thread Starter
Senior Member
Joined: Mar 2002
Posts: 333
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From: LI, New York
All of them, as much as I can...
Popping sound, gas cap area?
I used to get this on my E430; now I hear it again on my E350. The SAs had told me it was some sort of relief valve in the gas tank and that it was normal. Is it? Anyone have the same experience?
Thread Starter
Senior Member
Joined: Mar 2002
Posts: 333
Likes: 0
From: LI, New York
All of them, as much as I can...
>>at idle at a light(radio/ac off)<<
Usually. It almost sounds like the gas cap door closing except muffled. I hear it when I brake and coast to a stop...then a second later, pop. Sometimes, pop, pop.
LOL a member said here when I posted it about my E430, that my car had a gas problem. It was farting
Usually. It almost sounds like the gas cap door closing except muffled. I hear it when I brake and coast to a stop...then a second later, pop. Sometimes, pop, pop.
LOL a member said here when I posted it about my E430, that my car had a gas problem. It was farting
Super Member
Joined: May 2004
Posts: 755
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From: USA
LS7 powered Corvette
I have heard of this once before....
Ask them to check out the fuel sending units. The sending units that attach to the tank from underneath the rear seat are actually two pieces. They are seperated by springs that allow the unit to flex up and down. The reason they have these springs to allow contraction is b/c when the purge system is operating, a vacuum is on the fuel system and can cause the fuel tank itself to shrink.... these can create the type of noise you are describing. The case I am talking about it was fairly obvious and happened about every time you drove the car. If the dealer doesn't hear it, they will most likely not attempt a repair.
I usually drive mine with the radio on but I will check it later and see what I come up with.
Ask them to check out the fuel sending units. The sending units that attach to the tank from underneath the rear seat are actually two pieces. They are seperated by springs that allow the unit to flex up and down. The reason they have these springs to allow contraction is b/c when the purge system is operating, a vacuum is on the fuel system and can cause the fuel tank itself to shrink.... these can create the type of noise you are describing. The case I am talking about it was fairly obvious and happened about every time you drove the car. If the dealer doesn't hear it, they will most likely not attempt a repair.
I usually drive mine with the radio on but I will check it later and see what I come up with.
