Strange Sound Emanating from My Coach

[Richard Barnes]

For two months I've noticed a sound as I sleep at night. It sounds like a muffled jake brake and it cycles over and over from high pitch to low. Since I've been in an RV park across from the Long Beach Ports, I actually thought it may have been the trucks that service this area 24 hours a day. But, I moved the coach this weekend to a quite locations and guess what, I woke at 3:00 AM thinking I had brought the trucks with me. I turned off every breaker in the coach and the sound did not go away. I was plugged into 50 amp power and the inverters were on but I couldn't tell if they were the cause. Any ideas to keep me from going completely nuts?

Richard Barnes

[jack14r]

some tank(water,black,gray) level sensors have air pumps that run every so often,I think that they sound like your description,they usually only run 10-15 seconds every 10 minutes or so.

[Richard Barnes]

some tank(water,black,gray) level sensors have air pumps that run every so often,I think that they sound like your description,they usually only run 10-15 seconds every 10 minutes or so.

This is continuous. It cycles over and over. It is not so loud as to be annoying when the TV is on or when the AC units are blowing but in the still of the night or day for that matter, it never stops. It is a mystery!

[JIM CHALOUPKA]

Well, I was thinking aux air comp until you said you shut everything off?

Is your coach up on the bags when overnighting, or is it down on the stops. If you keep it raised, where is it in the morning? The sound could be that last evacuation of air as the pressure gets low and the bus sinks to the stops.

Just guessing.

JIM

[Richard Barnes]

Well, I was thinking aux air comp until you said you shut everything off?

Is your coach up on the bags when overnighting, or is it down on the stops. If you keep it raised, where is it in the morning? The sound could be that last evacuation of air as the pressure gets low and the bus sinks to the stops.

Just guessing.

JIM

Jim it is on the bags at all times. This is a real mystery and I'm sure it will drive me absolutely nuts before I find it.

[truk4u]

Richard,

Putting your conversion and year in your signature would help you with answers. I don't have a clue what you have.

[Richard Barnes]

Richard,

Putting your conversion and year in your signature would help you with answers. I don't have a clue what you have.

1998 Liberty XL
Thanks, Richard

[Richard Barnes]

Richard,

Putting your conversion and year in your signature would help you with answers. I don't have a clue what you have.

Tom,

I have a 98 Liberty XL
Thanks,
Richard

[Coloradobus]

Richard,

Could it possibily be one of the Inverter fans?? Don't know about Liberties, but in Marathons of our vintage, the fans are hardwired and shutting off all breakers wouldn't silence them. One could be going bad.

[Jon Wehrenberg]

Richard,

Now I can get specific. If the noise is under the dish, see if the satellite is looking for a signal. That thing makes lots of noises if it loses a signal due to trees, heavy clouds, or just because it is acting up.

On both sides of the last bay you will hear the timy pumps that Jack and Roger mentioned. They cycle periodically. If you think that is what is doing it, turn off the switches at the level displays over the front windows in the TV control box.

If it is the aux air compressor you will hear that coming from beneath the floor somewhere under where the floor slide is. The bottom LH switch in the electric panel should kill that noise.

If it is the inverter fans, making lots of noise is a bad thing. My inverters are under the bed. Yours may be in the electric compartment. Regardless of where they are, if they are making the noise that needs to be takne care of pronto. A noisy inverter fan is one that is failing, and if it does quit heat can damage the inverter.

Other things that make noise in my coach are the refrigerator. It has a condensing coil fan located in the rear bottom near the compressor. If that is the noise that needs to be replaced also or your refrig is done working.

There are a lot of other fans and noise makers but they are assocated with stuff like the Webasto. The Webasto sounds like a jet plane when it lights off. The circulating pump sounds like a whine, and the various heat exchangers throughout the coach just make a lot of noise.