So, I've been fighting a vibration that started that feels like it's coming from the driver rear, only happens 25-35 MPH, only after the car has been off and for the first quarter to half mile. (I made another thread before but this has some different info)

Now, here's where it gets tricky. I just started driving with windows down and noticed the second the vibration stops, I hear an air blow off. So, what could possibly have an air blow off valve that could cause a vibration and only when I start driving, and only at those speeds?

 

Airmatic pump? but it's located up near the left front headlamp

 

It's funny you say that because I was just looking at some things and was reminded of something. I noticed the pump was loose one day when i was under it, so I went to turn the nut to snug it up and the bolt broke. I managed to get the nut back on the bolt about 3/4" further down the bolt so it was secured but obviously not in the same position. I feel like this vibration and that instance happened at the same time.

I just looked through some threads where people were saying there was a vibration and that was it, a broken mount for the compressor. Perhaps it just feels from the rear, the speed thing doesn't make any sense unless the compressor isn't kicking in till those speeds to adjust ride height. The blow off sound does sound like driver front which I would pin to that compressor.

So, is there a potential fix other than all new mount for it? If I can right something up for that 1 bolt to not make it vibrate that would be awesome, because replacing that whole mount will suck.

 

It would appear Bean93x's comment was just what was needed to solve this problem that's been racking my brain. I checked the compressor and it wasn't super stiff on the mount, but I backed off the one that broke before a little to make it as loose as the others. Then I noticed something, one of the air lines had a tear in it. That would explain why I heard the blow off so loud and would certainly make the compressor act irregular and move more. I replaced the hose, barely hear the blow off when I was listening for it and no vibration all 3 times it should have done it.

So, the compressor coincidentally was doing some function at the speeds it was doing it at, go figure.

 

Lol I noticed mine doing it as well. Same thing. Busted bolt.

The reason you hear it for the first bit of the drive is because the car always does a test to see if everything working properly, and it also fills the bags and tank incase they're low. Usually takes 10-15 seconds.

 

The odd part of that is it only did it 25-35 MPH. I feel confident it was related to the air line issue. I'm just glad it's fixed, it was very irritating, especially being predictable.