Hello, and question about rattling noise

[cardtarget]

Hey everybody, today is my first day as an RV owner! Bought a 2002 Coachmen Pathfinder Class C. 75k miles on it. Ford E450 chassis.

Anyway, drove it about 200 miles home today and it drove very well except for one weird thing. A while into the trip (or I didn't notice at the beginning), every time the RV would cross 20-21 MPH, there would be a noticable rattle from the front right part of the engine (passenger side). It didn't sound like grinding, but more of a shaking rattle. It would last for a few seconds at most, and then back to running fine. Seems to be slightly more pronounced upon deceleration but appears when going 20 MPH both when accelerating or decelerating. Any ideas?

Looking forward to getting involved in this forum and fixing up the RV for a good trip this summer.

[pnichols]

cardtarget wrote:
My wife was in the passenger seat tonight and to her it felt like it was coming from under her seat.

Same here!!

P.S. My rattling is harmonic also.

[cardtarget]

It sounds as if something is loose and rattling, but definitely a harmonic rattle sound.

My wife was in the passenger seat tonight and to her it felt like it was coming from under her seat. Does that help narrow it down at all?

[pnichols]

I've had the same rattling in my 2005 E450 Itasca Class C for several years now. So far I haven't been able to figure out what is causing it ... it first started during an RV trip along RT66.

I've banged all heat shields from down below and above and it doesn't seem to be coming from them. I'll check the dipstick tube next. I hope it isn't the cat converter - that'll be an expensive way to eliminate a rattle.

[navegator]

On some units there are heat shields that were installed by the coach manufacturer rather than the chassis builder and they can rattle, also check the heat shields on the catalytic converter, they come loose sometimes.

Other sources of rattles are the beauty covers, on the wheels they are held by two nuts, I took mine off after driving down an alley and hearing the rattle they produced.

Also check in the engine compartment the oil and transmission dip stick tubes, if they are loose they can rattle.

navegator

[OFDPOS]

Hope this makes since ?! Does the noise sound tinty or more solid metalic ?
Reason why I say that if its a heat shield on the exhaust there can be up to several along the exhaust route it sounds tinty , if its suspension it would sound more metalic meaning solid.

I know I have found several heat shields missing nuts/bolts or just loose and just the right harmonic balance ( acceleration/deceleration ) would make that rattle noise.
Worth a look to crawl or have someone crawl around looking at the heat shields etc.

[tatest]

If it is road-speed dependent rather than engine-speed dependent, the rattle is likely coming from some part of the front suspension, wheels or brakes rather than from the engine. At 20 mph accelerating you will still be in first or second gear, slowing down you will be in third, maybe still in overdrive, at that speed. This gives you more places to look for the source of the noise.