Anyone ever experience this?

[Doozi]

Last night I got home from work at about 5:30pm and parked the 4Runner in the garage. At about 12:30am (7 hours later), I went out into the garage and heard what sounded like a neighbor's air compressor running or something similar. Then I realized that it was coming from my 4Runner! I walked around it trying to find the source and it was coming from somewhere near the fuel tank... probably the fuel pump. I went in the house to grab my keys and when I got back to the garage, it had stopped running. From when I noticed it until it stopped running was probably only about two minutes.

Could it have been the fuel pump? Is it normal for the fuel pump to cycle while the vehicle is off?

For the record... it starts right up, runs great, and has no symptoms of anything wrong.

Thanks!

 

[satanos6668280]

Does your runner have rear air suspension? Sounds like the compressor leveling it out no the fuel pump shouldn't cycle when the key is off

 

[gm350reratliff]

Could also be the EVAP system doing a self test.

 

[Cali4Runnea]

It's Alive, it's Alive! Bwhahaha....

Sorry, I have no clue, I've never heard something like that before from my Runner.

 

[Doozi]

No RAS, but I didn't think of the EVAP system... that could be it. I agree that the fuel pump shouldn't cycle. When I later turned on the key and the fuel pump cycled, it was a different sound... faster and higher pitched. The noise that I heard was definitely more of an air pump sound like one of those aquarium bubblers. I'll look into the EVAP system. Thanks!

 

[earthrealm]

should be the evap system doing a self check..its also written on the manual.....the system checks for leaks by pressuring up the system some hours after being parked

 

[BlackWorksInc]

Its the LDP (Leak Detection Pump) kicking in. The EVAP system kicks in a couple hours after shut-down to test for leaks, its all automated and uses its own little compressor and calibrated .020" hole and stuff; super neat stuff that makes testing for EVAP problems pretty damn easy.

 

[Doozi]

Thanks for the info!!

 

[2007toyota4runners]

In the owners manual its states that a strange sound may be emitted several hours after the vehicle has been turned off. Its just a self diagnosing system that comes programmed into the car. Its completely normal