Recently my wife, and I have noticed a strange higher pitched humming noise coming from her tc2. It does it at completely random intervals, and only when the car is turned off, and no key in ignition. It seems like it's coming from the little black box next to the gas tank, or the fuel pump, or something in that area. Can't seem to exactly pinpoint it. It stops as soon as you turn the key to acc. Anyone have a similar issue, or happen to know what causes this noise? More concerned of it draining the battery than anything else. TIA for any help

 

There are a few things it could be, if you let your car sit on E for awhile, dirt, debris or other gunk can build up could be blocking it up. Check to see if there's any damage to the fuel pump b/c that can also make it produce a whining noise. Or maybe another part of the car is damaged. If a hose that xfers fuel to the engine or carburetor is damaged it can release air into the fuel system reducing the pump pressure causing it to whine.

 

Car is off when this whine occurs so how could it be the fuel pump? Most likely it is some kind of ventilation system, I haven't paid any attention to mine but I know my parents Toyota's do this at random times.

 

"Noise from under vehicle after turning off the engine: Approximately five hours after the engine is turned off, you may hear sound coming from under the vehicle for several minutes. This is the sound of a fuel evaporation leakage check and, it does not indicate a malfunction."

That's from page 20 of the manual.

I've owned my car for almost 3 years and have only been lucky enough to catch this process once.

 

this


heard it only once, referenced my manual like anyone else would do, and course i found it.. double checked with my buddy who works at my toyota dealer and he confirmed, says only 1 out of every 50 customers at least has noticed it, other cars do it as well

 

My wife and I have 2011 & 2012 tc's and I have heard them both make that sound and was told its normal.

 

Thanks everyone for all the responses. That's actually kind of interesting. Something I never would have guessed. Never dawned on me to check the manual either...

 

My son heard it for the first time and came into the house and said "You didn't just buy a car, you bought a Transformer".