I drove my fb last night on my once a week keep-it-alive-until-i- can-fix-it-up-right trip...just an errand to the store. Took the long way home thru some twisty roads and was driving it harder than usual. Near the end of my imaginary autocross there was a horrible rattling noise...generally from the front right..but not as far on that corner as would seem to be the wheel. Pulled the clutch in...not the motor.rpms did not affect it..like something spinning was hitting something else...slowed with road speed...nothing while stopped.
Brakes were good..gauges were good..steering as bad as usual..
Pushed onward gingerly... It seemed to be getting quieter and after a mile it was gone. I made several mild shicanes on a straight road but noise did not come back.
After getting home my son reminded mine it had done this a few years ago when it was his car and i was testing it out..on the same twisty road no less. .at that point i went through the front end...brakes tierods etc...didn't find anything then though and i bet it hasn't been driven that hard since.
So what the heck...something that's been there for three years and only shows up when pulling some force on the turns...then goes away. Body flexing enough so the driveshaft Shroud hits the driveshaft? Rear end getting misaligned so the shaft is hitting the body? I remember when it would happen before i could feel the rattle somewhere on the transmission hump on the passenger side...a little forward of the shifter....any ideas?

 

Idler arm bushings need replacement is my guess.

 

That would be my guess, too. Sometimes with the stock part, the bushings will take a set in an awkward position and allow front wheel misalignment. Once you get it back on a straight line, the bushings return to the centered position. Simple check, just grab the idler arm from below and try to move it around. Check out the MOOG idler arm replacement which will survive WW3.

Could also be the transmission tail shaft mount which would allow the Trans to slide far enough to let the driveshaft scape against the heat shields, which is also an intermittent issue.

 

front wheel bearings can do this too, as many people forget to grease it all back up when changing the front rotors.

 

^ this was my first thought, they got hot and may have been seizing up slightly, and after they cooled of with normal driving they cooled back off and all was good again

To me it sounds like something got hot, and cooled back off, which usually an idler arm doesn't do

 

Thanks for the replies!
I drove it again the next day because I was working on my van, made several short trips to the auto parts store, hardware store, etc...
I whipped one turn hard, even got the back end loose (on purpose and not in traffic) and it did that rattle thing but just for a moment and not that loud.

Im pretty sure we replaced everything in the front end over the last 10,000 miles, but I will check that stuff out again. Maybe inspect the drive shaft for some fresh scrape marks.

I will say this, the rear suspension is getting pretty noisy over potholes, I gotta go thru that as well.

 

Check the idler arm bushings and ensure the bolts are tight that secure the idler arm to the body. Your best bet is to get the car in the air on a lift and start inspecting everything. Did you have an alignment done after you replaced the suspension components in the front?