Undercarriage Noise

[mustangguy506]

I'm a bit stumped and could use some help.

2004 Mach 1
45,000 miles
off road x-pipe
borla catback
CAI
4.30
Steeda Tri-Ax shifter
custom tuned

Very recently I've been getting a loud 'clack' noise from the drivers side undercarriage. It appears to happen only when weight is transfered from front to rear or rear to front ie. when I accelerate (doesn't have to be like I'm leaving the hole at the strip - even very moderate stop light city driving) or downshift from 4th to 3rd while in the stopping process. I have 4.30's out back so it slows the car quite a bit, much more so than stock gears (again not aggressive stopping, the nose isn't flirting with the ground, just normal driving). Happens 98% of the time when its wet (cars wet, streets are wet). I've tried to make it happen in dry weather (I hammered on it pretty good, only did it once maybe twice). The car appears to have sub-frame connectors - I'm not sure if that is a stock component on a Mach 1 or not.

If I had to put a location on the noise I would say at or just behind the drivers seat but absolutely not coming from inside the car. It performs fine, no difference in anything but the added noise. I can only assume that will stay the same right up until it breaks


Anyone have any ideas or suggestions?
Thanks!

 

[trinity_gt]

Odd that it's most noticeable wet.

You might want to verify the condition of the engine and transmission mounts, whether there are any witness marks on the floorboards or SFCs indicating something is touching them.

Sounds like perhaps something reacting to engine torque (again...can't explain the wet/dry thing though...) Perhaps a loose engine mount is allowing the engine to move and it's causing the H-pipe to hit the floor or something...

 

[97rioreddohc]

I've had that happen to me a couple of times as well. The first time it was the muffler hitting the side of the frame rail when taking corners etc.. (try grabbing on to the tail pipe and move it left to right to see if you can duplicate it). Second time was just here recently when i added U/L control arms that needed lube on the bushings (so maybe adding some grease to the bushings may help). Those are my experiences just thought i'd share incase they help.