mystery sound in my coupe's behind
 

Hi to all: i'm a newbie here so please bear with me, ..Anyway, I recently purchased a 2004 crossfire, 2 months ago, and i've replaced front bearings, leaky seal, on p. steering unit, shocks (all 4),and that's it. I did the shocks, but since i finished the rear shocks, it may be a coinscidence, but now i have this random banging sound , in the rear of my car.its like if i had a spare tire compasrtment, with no tire, but the chain keeps banging back and forth.Sometimes when i hit a bump,when turning, well, its hard to pinpoint when and if it sounds off, or not. at first i thought the exhaust tips, but they're pretty dam secure. they have a little movement, but upon testing them to see if they're maybe too much play, i dont see noway they couild be hitting the body, back there. is there an empty space below the jack, and flat tire area, that i'm unaware of.. Cuz like i said, the car is new to me, and i'm just kinda lost with it.. I'e never had a car with a rear axle like this. These cars are a special breed. Everytime i open, owners manual, i learn so much abouit this car, and all the little , these and those, things in my car.. I'll stop for now, i'm getting off the suject at hand. But please if any of you guys oiut there, have any siggestions, advice, anything at all, please send it..it'd be much appreciated.. pre-thanx to all. charles921545

Re: mystery sound in my coupe's behind
 

Congratulations on the new car. I would start by checking the tightness of the bolts on the new shocks.

Re: mystery sound in my coupe's behind
 

;) Hello Charles, welcome to the best car forum I ever belonged to. While your there checking the shock bolts, check the sway bar (?) swivel mounts above the rear axle on the body. Some have had them break away (bad welds) on one side or the other. Only other question I have besides already pointed out is did you check the bolt diameter before mounting the lower shock mounts? I had a set of rear shocks from RockAuto (for my truck) that had a larger bolt hole, and if I had installed them the lower bolt would have 'floated' in the mounting. I would not have a smaller diameter bolt in a larger hole on lower shocks. RA ate the whole set of 4 (it was a kit) because of that defect/miss-listing. Hope you find it, good luck! ;)

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Re: mystery sound in my coupe's behind
 

If you replaced with KYB's, then you might have to add extra washers at the shock top bolts in order to get then nuts tightened enough to compress the rubber bushings before you run out of thread. I did, and the clunks went away.

Re: mystery sound in my coupe's behind
 

Check out my profile for my ongoing saga of chasing down noises in the rear end. Most recently, I turned on the car radio while working on the car and could hear a clunking emanating from the ghost spare tire. I could only hear it because the bass was way up and I have a sub in the back, and I was under the car. But it gives me a new series of tests to run, looking for this noise.
Basically, noise in your back end under various conditions could be anything. Make sure everything is tight, then do it again. Punch things with the fatty part of your balled first and listen to the noise. Tug, push, and twist on things. You gotta test everything at every angle. Take out everything in your trunk., and the spare tools, and the foam then test and bang with fist. Have a little person sit in the back and point at the noise. It's in the back end, but it's not guaranteed to be suspension.

Edit: and Godspeed you poor SOB

Re: mystery sound in my coupe's behind
 

Generally speaking, if you do something to the car and then you have a noise that was not previously present, go back to your work to find the culprit. Check everything that was changed or moved, tightened, loosened, etc. Don't over complicate things, they are usually simple.

Re: mystery sound in my coupe's behind
 

If the noise was there before you did the shocks I would guess it could be the mountings for the rear sway bar breaking loose. It could be by coincidance that they have just broke loose now.

Re: mystery sound in my coupe's behind
 

I had the clunking after installing the KYB's, I added extra washers to the tops so I could compress the rubber bushings before running out of thread.
You can easily eyeball the sway bar mounts to see if they are separating from the body.