I was wondering if anyone else’s compressor makes different sounds when it’s running. Sometimes when it is running the sound changes for a second or 2 and then goes back to normal. Is this a normal thing or something to worry about?
Thanks
is this when the vehicle is running or just on battery? Mine will make noises every now and then if i have another big draw at same time compressor is running… example- roll up both windows at same time (headlights dim a little too), or if you have a power hungry stereo…
Its just the alternator trying to keep up supplying the power most likely…
My compressor sounds like it is working extra hard (speeds up) sometimes… but usually when the pressure is getting up to about 110 - 120ish
mine changes with the times when the check valve opens and closes goes in/out of sync with the compressor speed. if you hear sharp rattling sounds then that’s another story.
I guess this makes sense. Usually I am just driving with the comp running to fill the tank and the tone changes. I don’t think I am doing anything else at the same time. I guess it’s probably the alt. trying to keep up.
I don’t have a gauge so I don’t know what psi it’s at.
i could not imagine not having a gauge… I have one in the bed on the tank, and have one in the cab …
It essential in making sure your pressure switch is doing what it is supposed to, and your compressor is working properelly…
If you have an extra port on the tank, get a gauge. they are cheap, usually $10 for a standard… If you dont have an open port, get a T fitting and split the output on the tank and mount the gauge that way…
My kit came with a gauge. I have an extra port but I don’t think even with a T I could get it to fit because of the way I have the tank. I don’t really think it’s necessary. If you disagree, please explain.
i have a changing sound on my compressor when i hit the brake 
must be sharing it’s load with the brakelight and the compressor
how long have you had the compressor? could the motor brushes be getting low?
It’s brand new. ( a few weeks) I figured it out today that it’s just sharing a load with other accessories. I hit the brake and it did it and I did it again and the sound changes. I don’t think it’s anything to worry about.
I did hit the horns under a bridge underneath a 6 lane highway and scared the **** out of 3 guys. One was a tough guy with a green mohawk and he cowered like a school girl.:eek:
The importance of the gauge is to make sure your compressor is shutting off at the right psi…
Good to have to diagnose problems when they arise.
I use mine on the inside of my truck to make sure i have a full tank to start my drive…
(if i was honking the night before and am just above the pressure switch turn on which is 110 psi for me, i will give it a little honk to kick it back up to 150 so i have a good strong blast waiting for that person that pulls out on me.
If you cant fit the gauge on the tank, of if the tank is under the bed, get some 1/8’ air line., adapters, run it into your cab…
Like Dan said. I know my 450 was old and going bad and it kept making random, not so good noises. Just tore it apart today and found the rod froze to the crank… Time for dual 480’s 
I am going to buy a remote gauge when I get some extra cash.