Roaring Sound Under Carriage

[jtrippy]

During our last trip we noticed a roar sound on and off under our 2300. This is the first time we have heard the sound. We took it to our local RV dealer and he is completely stumped. He said he has no idea. We thought it was just when moving and the motor running. We discovered yesterday, just closing the door started the sound. Any ideas. It is very annoying.

My wife just told me that it sounds like a gas furnace when it first starts up but continues and then quits.

[bgilly]

Check the engine exhaust pipe hangers. The noise might be the rub/vibration of a loose or broken hanger. There are about 3 hanger positions down the coach. You might also check the heat reflector plates. There are at least two heat reflector plates, one as it passes the propane tank and one as it turns to come out from under the coach.

I found my mid-hanger was loose from the exhaust pipe - the J-hook weld broke from the exhaust pipe. Now I have to determine if it is a Forest River fix or a Ford fix since some frame add-on is done after it left Ford.

[bclemens]

I'm guessing that is a FR fix since we handle all of the exhaust work. Heat shields is normally us too.

[bgilly]

Thanks.
Now I need to find someone closer to do my FR warranty work. My selling dealer is over 60 miles away.
Bobby

[RoadTrip]

Weird. First thing I thought of was that maybe you ran over a lion or cougar or something on your last trip and it was still stuck under there.

But that seems pretty unlikely…can you tell me more about what conditions the roar happened. In my mind, you're driving down the road and then "roar". And then you standing in a parking lot, engine off all closed up and wife closes her door and "roar".

Was it happening with the engine both on and off?

Have you checked the furnace? It will automatically cycle if left on. I found that out our last trip when it turned on in the garage one evening. Hadn't turned it off from the last trip...

[jtrippy]

I had my guy check the exhaust system etc. while the sound was happening. No luck. He said it may be a muffler baffle blown, (it does resemble that type of sound) but since it will do it when the engine is off, that is out.

It happens when you close the door or the other day while I had help with putting on the cover, the person on top was walking along and the vibration started.

Could it be the Firestone air springs making this blabbing vibration sound when the coach is shaken, the vibration starts and ends in about 10 or 15 seconds. When you are driving, it comes and goes with the coach going up and down with the road.

[bgilly]

I didn't understand the noise occurred when the engine is off. You got me stumped on this one.
I can't think of anything sounding like the furnace with everything off (refrigerator with an outside fan? )

Bobby

[jtrippy]

Everything is off.

It is like you shake something that vibrates and you quit shaking, it stops. When you close the door, it vibrates the unit and then the vibration from whatever starts and quits in 10-30 seconds.

Do you think is may be the Firestone bladder letting off air or something?

[paulmlac]

Originally Posted by bclemens

I'm guessing that is a FR fix since we handle all of the exhaust work. Heat shields is normally us too.

Oddly enough, I had just noticed what seems like a louder than normal exhaust sound too. Are you saying the exhaust system from engine to side exit is FR and not Ford? Seems like that would be Ford as part of the chassis.

[bgilly]

Originally Posted by jtrippy

Everything is off.


Do you think is may be the Firestone bladder letting off air or something?

No, I don't believe it is your rear Ride-Rite air assist system unless you have an onboard air compressor that would be a pressure maintainer - but not likely.

Do you have auto leveling system? Maybe one of the hydraulic pumps are cycling from a short which reminds me of another reported noise a while back with the battery isolation monitor: http://www.forestriverforums.com/for...ise-44435.html

Bobby

[jtrippy]

I do have the Big Foot system. They do leak off occasionally but a buzzer comes on to let you know to raise them. Do you think a jack would make some blabbering vibration noise by just shutting the door?

[bgilly]

I mention it as if there is a short. There are two solenoids at each hydraulic station. If there is a short everything "normal" is out the door. I'm thinking of items that would make noise with the engine off and nothing else in the coach running.

[MotocrossCamper]

Does the new Ford chassis have anti-lock brakes? A good friend just had to have his pump that controls the anti lock brakes on his ford pickup changed. It malfunctioned and would randomly start running even when it was parked and turned off. If you have one you should be able to follow the brake lines down the frame rail and you will come across a pump that the brake lines run into. You can unplug the wire harness and see if it stops the problem.

When it ran while he was driving it was loud enough to hear and feel it in the cab.

[jtrippy]

I don't know. I need to check that out. Thanks.

[jtrippy]

I wish the factory rep would throw his two cents in?

[bgilly]

Originally Posted by jtrippy

I wish the factory rep would throw his two cents in?

If you are referring to Brian; he has read the topic and commented on posts he had clear information on, otherwise he is like the rest of us in trying to diagnose something strictly on a narrative. Just one of those that you have to be with the coach to properly diagnose.
If your dealer doesn't have a clue (the ones that are able to crawl all over the coach) - those of us on the other end of the World Wide Web are surly in the dark.

JMO,

Bobby

[jtrippy]

Got it.....Just thought they may have had a slant on the subject since they are the people who built it!

[bgilly]

An understandable assumption but I believe if he had something to say to check he would have by now.

[fonzie]

Could it be your water pump cycling?

[jtrippy]

Yeah, I think your right. Maybe he is checking on it for us. Thanks for your heip.

I am going to try to make a video and post it on you tube. Maybe that would give you a better understanding.