Dodge Repair/pressure in fuel tank and whining noise
QUESTION: 2004 Dodge 1500 with 184K miles. Got a P0441 and the truck was stalling at stop lights. Replaced the Leak Detection Pump. The error code went away and no more stalling at stop lights. But now when I open the gas cap I releases a lot of pressure and I am now hearing a whining noise while the truck is running. Any idea of what I have wrong?
ANSWER: Hi Rick,
You may have not experienced the pressure you now notice because of the faulty leak detection pump which in fact pressurizes the tank on and off under control by the computer. So what you are concerned about may actually be normal. The evaporative emission recycling system is rather complex but it is well-monitored and when there is a problem it will likely produce a fault code. So if there are now no codes, the system must be working properly.
As to the whining noise, that is very difficult for me to conjecture about. So again. occasionally check for fault codes and note any persistent illumination of the "check engine" light.
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QUESTION: Thank you Roland...appreciate your quick response. Wish you were my neighbor. As for the whining sound...I believe from what I have read it may be the fuel pump? But never heard it before and never had that much pressure released when I have opened the gas cap. Sounds like I'm opening a big coke bottle. No codes but just concerned that the whine may be related and don't want to be caught down the road with the pump going out.
The fuel pump is located inside the fuel tank so try to localize the whine relative to the fuel tank. Does it seem to be coming from inside?
The fuel pump sound can be heard by simply turning the key to the 'run' position (have a helper do that while you crouch down near the tank to listen), and you should hear its sound for about 1 second, and then it ceases. You would hear it again when you turn the key to "start" position but it may be hard to hear it above the sound of the starter motor and then of course the engine may start as well. It will continue to run as long as the engine is running, but as soon as the engine dies or is turned off so too will the fuel pump. So that would be a way to determine if the whine is indeed the fuel pump or not.