vacuum valve cutoff whine

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merope
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Joined: Wed Jul 22, 2015 4:02 pm

vacuum valve cutoff whine

Postby merope » Wed Jul 22, 2015 4:14 pm

Hi Everyone,

I have an 04 Pathfinder (R50) with 110 k miles. Recently I started hearing a whining sound when shutting the car off. I climbed under and identified that the vacuum valve cutoff between the fuel tank and the EVAP canister is making the sound, which is kind of weird. But tapping on it and pressing it made the sound stop and I could definitely feel it vibrating.

Q1: why is it doing this? I am certain it is not normal.
Q2: how big of a deal is this? I'd assume it is not, it will not cause the car to stall, it is "only" emissions.
Q3: should I replace?

Thanks!


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smj999smj
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Joined: Sun Jan 22, 2012 11:13 pm
Location: Prospect, VA

Postby smj999smj » Mon Jul 27, 2015 5:42 pm

There are several valves in the evap system. I'm assuming you are referring to the white plastic vacuum cut valve that has 4 vacuum hoses going to it, IIRC? It could be a faulty valve; there is a component test procedure for the valve listed in the factory service manual. I believe you need a vacuum pump to test it, but it's been a long time since I had to test one and my memory's getting bad! If the valve tests bad, then it should be replaced, obviously. It won't cause a drivability issue; it's for emissions.


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