If you have a 3" or larger over the axle exhaust pipe installed (do you??), it WILL contact the stock upper panhard bar on bad bumps/potholes, and when you get bad axle/wheel hop during launches (my Mufflex 3.5" over the axle section does this and it sounds louder than a jackhammer back there!).

 

I have the stock cat back with a magnaflow muffler welded in at the stock location. It's good food for thought though..I really need to get another go pro..then I could get video recording underneath while driving so that I could hopefully capture what's going on!

It's not a loud BANG at all in my case..it's a "loose" metal sound..almost like a heat shield or something. Maybe it's
the muffler hitting my 98's steel gas tank. But the exhaust is really secure I don't know!

 

did you check heaven forbid....the straps holding the tank in place are loose

 

I banged around that area with a rubber mallet and I didn't hear anything loose.
Are the straps attached with bolts are welded on with the 98's any idea?
Looks like it might be one of those annoying things I have to live with.

 

See if the noise goes away with the rear seat folded down flat.

 

Cool idea. ill try it on my commute tomorrow a.m.

 

Hmm..tried it..no dice. I think I'll have to wait until
I have a go pro that I can hopefully place under the
bumper to capture the sound.

 

^ Well, that gets you somewhere and eliminates a few pesky sources inside the car.

I also like to have someone else drive while I listen on the passenger side just to make sure I know the area its coming from. Sometimes, sound can be thrown around weird and you may be hearing it on the driver's side because that's where you have an ear closer to outside sounds.

Does the sound or pitch change with speed? Have you tried pressing on the rear corners of the car with the thing parked, so you can compress the suspension and let it rebound? Do you hear the squeak when you do that?

 

Good suggestion. Now, to find someone who will: (a) be confident driving my car (b)need a wide open parking lot haha. The squeak appears to be gone since the muffler shop "lubed some things up underneath." The banging over bumps and dips is still present.

No change regardless of speed. Yes I have. I've also tried opening the trunk and moving the quarter panels back and forth (no noise.) I've lubed up the latches with dielectric grease as well as spray lubed the trunk struts. Sooner or later I'll run out of things lol.

To me, it definitely sounds like it's coming from the rear of the car and underneath. But
sitting in the passenger seat would really help verify things!

 

... And during an Albertan winter!

You might also learn something by sitting in the back seat.

Most of the time the banging comes from loose stuff under the car or something in the spare tire compartment. You might empty that entire compartment out for a drive and see if that changes anything.

 

Indeed! Although, we are above zero again finally
and it's looking rather spring like.

Wide open parking lot is the way to go..gf does know
how to drive stick but she's scared of the powa
I figure a wide open lot is safe for her..and my car!!

I'll also try and remove the random crap I have in
my trunk, a bottle of oil and some microfibers are
about it but who knows.

I'll also check the jack again. Maybe wrap it in
a microfiber to buffer any potential noises.

 

Did the muffler shop take the sway bar bushings apart & grease the inside where they contact the bar??? Or just spray outside of them??? Only squeaks & clunks I have had in that area are related to the rear sway bar, as soon as it was greased it went away & needs grease once every 6 months or it comes back

 

They weren't really specific as far as what they actually lubed. I think
they just sprayed silicone spray in random areas. There's no way that they
took the bar off or anything. I'll tackle that when my drive shaft loop comes
in later this week (greasing the sway bar bushings/endlinks.)

 

So I removed everything front the trunk including the jack (no spare
tire with my car.) The noise still persists, although maybe it's a little
quieter (loose clunking sound from rear over speed bumps and dips.)

 

I put new lowering springs and shocks ball joints and tie rods and upper a arm bushings and that got rid of my clunking in the back ....i think u have a busted shock ......and if its still squeaky it might be ........ contributed to a foam bolster under your rear passenger sail panel on the inside their are wires that run around it my foam was loose and the double sided tape that was holding it in place was so old it came loose and was rubbing against the wires aswell....verrrrrrrrrrry annoying

 

How would I go about diagnosing that? We are talking the struts not the trunk shocks right? The struts are SLP bilsteins which were installed last October. Trunk struts look ok, they hold up the trunk but are a little slow. When I pulled the wheels off a couple weeks ago, I didn't see any oil coming out of my struts or anything unusual. It does make sense what you're saying though..just wish something could pop out so I could go that's it!! And fix it.

Should I take the car back to the muffler shop and ask them to test my rear struts?

 

well mine had a really bad clunking noise going on on the right hand of the car in the rear ....but your speak is also happening in my car in the same area with more rapidity ....over every bump...and crevice ......im going to have a bunddy drive and im gonna hop in the trunk as I have limo tint in the back window nobody will see me

 

Let me know guys what you find out my just be f-body woes

 

Had this problem in 3 of my cars, one had a loose ebrake backing plate which was quickly remedied,

The other 2 cars I had to replace the rear wheel bearings and axles. The seized bearing would etch a groove in the axles and when you hit a bump the rear end would rattle in the groove over every little bump in the road. So the sound you hear is the axle rattling against the bearing. You won't hear the whine from the seized bearing until you pull out the carpeting but it's there.

Soo change your rear end fluid, pull the rear end cover off and remove the c clips holding the axles in, pull the axles out and inspect the bearings and axles for signs of a seized bearing

 

someone told me to do that ...and I did....itll only cost about 200 to fix it yourself ......only after I got done it still did it ....so have of me thinks i wasted 200 and the other half thought it was a preventitive step :/