2002 Mountaineer...

Underneath the passengerside dash board. There are vacume lines that plug into a black plastic round little container. I have an small air leak out of it, but wondering what the heck that vacume line controls?

any info would be great!!

 

Sounds like your accumulator. You have a little capsule looking tube that holds vacuum. When you turn the heater on, the blend door is actuated by vacuum and it controls the inside/outside air vent. When you have this actuated and say, floor the gas pedal, you loose all engine vacuum. This accumulator keeps enough vacuum on the blend doort to keep it in position until you let off the gas and engine vacuum is restored. If it is leaking, I would suspect your heater controls to be off a bit too.

 

Thank you VERY MUCH!!

whats happening is that once I start to truck, there is a whisling noise from that capsule looking thing that last maybe 5 seconds. As soon as I step on the gas, I hear it getting louder and faster, only when I have my foot on the gas pedal.

when I turn the truck off, there you hear the whisling letting air out of that capsule that last a good 5 or 6 seconds. I crawled under there and tried to push in the vacume line tight into that capsule, and acually put silicone around that area to keep the air in, it worked a little bit, but sill does it.

I know this is a little thing, but it bugs me :-(

 

More than a little thing. This is called a vacuum leak. This condiion lets unmetered air into the intake. The computer doesn't know the air got there so it does not provid enough fuel - runs lean. The O2 sensors can compensate for some of this but if te leak is big enough, it could cause serious engine damage - siezed piston. Doesn't sound that bad yet but I would address it ASAP.

 

I did take it once to a dealership already for this concern, the tech test drove it with me, confirmed the noise, but then said "it's normal" ???!!!!! I know its not normal since it did not do this when I bought it, but he went on to say that I should not be worried, but when when reading your last post, this scared the hell out of me, the last thing I need are engine problems due to this!

I feel like taking it back to that dealer and getting someone else to look at it

 

Is it still under warranty? Maybe you have an extended one. If so, sure make them fix it. If ti's normal, tell them to show you how this noise is present on any one of their new vehicles out on the lot. Morons.

If it's not under warranty, take it apart and fix the leak. Not sure if it's a bad line or a cracked accumulator but it should be any easy fix.

 

It only has a Power Train warrenty remaining. After reading your post, I went outside with a bowl of soupy water and a brush trying to see if I can find exactly where this leak is coming from. I applied the soupy water to that little black container, and the vacume lines connecting to it. I started the engine up, and nothing was bubbling with the soupy water?? I turned off the engine since it releases air for 5-6 seconds so I was hoping I could find that spot then, but still nothing was happening. But I still hear the leak. I pulled down the glove box and took a look at the blend door is it? the foam the moves back and forth? The air leak sounds like its inside or very close to that thing but I can't pin point it.

this is frustrating, but thank you for all the help so far you have been giving me!