Fixed my hissing Explorer

[TequilaSnrs087]

About two months ago I got the typical vaccum leak hissing from my Explorer along with rough idle. Turning the truck off and restarting it fixed it that time. After that, I would occasionally get the hissing and rough idle. Usually flooring it cleared it up, and it wasn't that bothersome. Yesterday, the hissing got really bad, idle was around 500 RPM, and I could not get it to go away with my usual fix of beating on the truck...this is a $950 beater afterall. I finally decided to look for the source of the problem. I popped the hood and checked all of the vaccum lines. They were all fine, but I noticed that the PCV valve was pushed 1/2 way out of its grommet in the valve cover. I pushed it down, and the idle got better, but was still rough. I bought a new valve and put it in. Idle is now smooth as silk, the hissing is gone, and the truck is much quieter at idle. Amazing the difference a $3 valve makes. Normally, the PCV valve is one of the things I would replace right off the bat with a used vehicle, but the previous owner provided receipts showing that it had been replaced recently. I guess it went bad quick though. Anyway, for those of you with a hissing Explorer and no obvious vaccum line problems, check your PCV valve.

 

[adub98]

Mine does it only in gear. If I put it in N, the sounds goes away. I really hear it in the drive through (the sound comes off the wall). Is this the same thing you were having? I do get rough idle from time to time.

 

[TequilaSnrs087]

I never tried shifting into N. Mine would do it off and on...shudder, hiss, shudder, hiss, shudder, hiss. Until yesterday it was fine once I got the engine RPM up. Mine was also loud at drive throughs, but I could hear it just sitting at lights too.

 

[adub98]

Hmm well I think my problem is either the AIC or PCV valve. It seems they have similar symptoms.

 

[rob17san]

Humm i should try this. Due to the fact I could not find the PCV valve, I never changed it. I am sure its original at 86k miles.