Shag Finger
10-03-2008, 10:28 AM
After doing some searching on various forums I have come to find out that the noise I have been hearing from my 05 Libby the last month or so is probably the evap self test. It sounds like a little compressor running for just a few seconds then shuts off. LOL its been driving me nuts because I will be outside, hear it and not know where it was coming from until last night. I was standing in the driveway talking to my father in law and it would happen every 5-10 minutes, sometimes louder than others and sometimes I was the only one to hear it. We finally figured out it was coming from the gas tank of the Jeep... WTF???? It is my daily driver except for the days I take the motorcycle to work and it has a little over 50k miles on it. It has been sitting in the same spot for a few days since I have been riding the bike to work this week and I thought maybe the TX sun beating down on the gas tank had heated it up and it was venting since the rear of the Libby faces due west when parked and the direct afternoon sun can get quite warm even on days when its only in the 80s, but this was at 9pm. I had also already popped the gas cap once to see if there was a lot of pressure in the tank, there was a little and I heard it release so I thought that was it. However, the pump ran again 10 mins later and there was pressure in the tank yet again, albeit a much lesser amount.
So, this makes me think, I know the fuel systems require the gas tank to be pressurized, but why would it try to maintain that pressure when the engine is not running, especially for a few days? This also seems to have started just a few months ago and I have owned it since new.
So, this makes me think, I know the fuel systems require the gas tank to be pressurized, but why would it try to maintain that pressure when the engine is not running, especially for a few days? This also seems to have started just a few months ago and I have owned it since new.