1998 Lincoln Navigator Strange Noise

Does it happen if you don't use the AC? Also, does it have an air ride suspension?

No, it does not do it with the a/c on. It happens when I am parked and not driving it at all.

Yes, it has air-ride suspension.

Sorry, I ment does it make the sound after using the AC? Also, if you have air ride, is the vehicle riding level and does it change after hearing the sound?

I honestly wouldn't know if it was riding level. How would I know that? I did notice that it appears to look a little "lop-sided" when I look at it from the front end while it is making this noise but I thought it was the air going out more on one side than the other. Again, it only makes this noise when it is parked and not when I am driving.

I've only had the vehicle for about one week. It was making this noise and the person said it was the air going out of the shocks or something to that. He said the SUV, when you start it up, will raise up and then when you are not driving it lets the air out. I personally have never heard this before and don't know whether to believe it. I'm afraid if I take it to a mechanic they will charge me an enormous amount of money to check it out so I thought by coming to this forum I would get the answer I am looking for. All I want to know is if this is normal or is it a mechanical problem that can turn into a major problem if not fixed.

As far as the A/C question.... I have not even turned the A/C on since I bought it so I don't think it has anything to do with this noise.

Cances are the air is leaking from the air ride. If it looks level when the it's running, chances are everything is ok. I asked about the AC because they will make a noise like that when they are turned off.