Hope you guys can help me out again,
2000 F150,SuperCab,5.4,Automatic,2wd,Gibson shorty headers,Magnaflow(Lightning) exhaust,117,000 miles...
I have an irritating moan/rumble/buzz that resonates throughout the cab and can also be heard at times outside the cab.It only does it at idle or just above idle in gear,doesn't matter whether its in drive or reverse.I can duplicate the noise by just barely touching the accelerator with my foot on the brake or with the e-brake.It is below 1000 rpm's and reverberates like a subwoofer.I have removed all of the heat shields above the exhaust,loosened clamps and retightened,loosened engine and trans mounts and resettled them,removed my bedliner,and installed an additional vibration damper further forward of the original.This has been happening for a while,but has progressively gotten worse.
One thing that I did yesterday was to put a jack under the exhaust hanger that is above the transmission mount and the vibration went away.I know it sound like I solved my own problem,but has anyone else had this same problem???..Can I remove this hanger without risking damage to something else???..I've searched,but is this a common problem,or should I just replace the hanger???.. Please help me out..!!!

 

Since I haven't been under my truck for awhile I'm not sure what exhaust hangers they use but this reminds me of a loose exhaust grommet on my Mustang TSB. They use a stainless hose clamp to cinch the grommet. Here's the tsb. Might give you an idea. http://www.themustangsource.com/gala...er_console.pdf

 

That is a different type of setup from what I can tell,but thanks for the suggestion....Anyone else have any ideas????

 

Anyone...Please

 

I have a 2000 f150 5.4 supercab 4x4 with gibson shorties and gibson super truck exhaust cat back out the side the y pipe hanger is hung with a square weldment off the trans mount that goes and bolts to y pipe, is the rubber square grommet in the mount missing or something?

 

Nope,.The Grommet is still there,but not sure if it is making contact within the mount or what...I guess its possible it could be deteriorated and/or be hardened enough to cause this,but I've done everything I can think of short of removing parts until I find it..

 

Could I possibly have an engine or trans mount that is collapsed internally that is causing this.I can see that the trans mount upper shell(don't know if that is the correct term) is not making contact with the crossmember..What I mean is,..It's not rubbing the crossmember.It doesn't take much pressure at all with the jack to make the noise go away..

 

If you only put upward pressure on the y pipe and it stopped maybe is is the grommet

 

With my engine running that y pipe doesnt really have any vibration to it

 

The grommet( Ford calls it an isolator) is available separately from Ford,have you or anyone else ever replaced it by itself before, Is it a pain in the butt,just curious,because I've only got one good Arm to work with...

 

I unbolted my y pipe there before ,but replacing it ,takes removing the trans mount, and supporting the trans up with a floor jack,unless you rather remove the y pipe

 

I just ordered the grommet/isolator from Ford..$13.00...I'ts cheap enough to try it out,I'll inspect the trans mount once I get it apart and post with my results...Thanks for the help...

 

It really just sounds like you exhaust needs to be neutraized. All you do is loosen the downpipes and any other joints in the middle of the exhaust system. You only have to back the bolts off just enough to where they can move. Not so loose that they flop all over, and loosen the nut that holds the crossover pipe on the crossmember if you still use it i guess. Once they are loose start the truck. yes there will be exhaust leaks. Put it in reverse, drive and then neutral. Shut it off and then tighten the bolts back up. I usually go back to front. I have done this many times. Sometimes it works miracles other times it doesn't. But at the end of the day it doesn't cost you anything

 

Thanks for the advice LLADNAR,I have already done just exactly what your describing.I even went a little further and loosened engine mounts,trans mount,bed hold-down bolts,and just about everything I can get to easily without too much teardown and reassembly.The only things I haven't replaced for this issue are the engine and trans mounts,along with this isolator for the exhaust.I'm going to loosen stuff up again after I get the part installed from Ford and see what happens.I remember that this same noise has been present for years,but it was always ambient temperature related.If it was hot like in the summer,its was noticeable but not always audible.When the weather was cooler,it never did it at all.I've owned the truck since NEW,and have always done my own maintenance and upgrades.I would like to say that I know this truck like the back of my hand,but this has gotten worse and more constant.Your probably correct about it being all bound up.I also seem to recall that this noise occured after I put in the shortie headers,but they have been on the truck for nearly 90,000 miles.Thanks again,I'll still keep everyone posted....