All,

I have a bad rattle coming from the rear of the car. It's done it for the last couple of years. I convinced the wife it was the stock cats so we got longtubes from Supermaxx. It kept rattling. It seems to get worse, and worse and...well you get the pic

So...ideas? I removed the heat shield 2 weeks ago...now it's twice as bad! Muffler, mount, Y-pipe...anyone? It seems to be coming from the passenger side in the trunk and freaking RUMBLES LOUD. HIGHLY ANNOYING!!!

Help please!!!! (And yes I searched but no luck)

 

Check to see if the Over-Axle Pipe of the exhaust is resting on the Panhard Bar. This would be the 3" Pipe that plumbs the exhaust gases from the I-pipe into the Muffler and is routed "over the axle".

When we installed a full exhaust system on friend's 98 Z28 the Over-Axle Pipe of the Magnaflow Catback was extremely close (almost touching) his Panhard Bar causing a rattle from the same area you're describing.

We ended up loosening the exhaust clamp at the Y-pipe to I-pipe connection and sliding the entire Catback towards to rear of the car then re-tightened the clamp. This gained us a little more clearance. Not a huge amount, but enough to eliminate the rattle.

Hope this helps. Good luck, man.

 

If its the upper panhard (stock) rod then just remove it.

 

It's the exhaust mount on the passenger side just past the axle (not the mount at the exits) Loosen the clamp on the I pipe and pull the entire catback towards the rear about 3/4 inch... I think you will see where it has been making contact with the mount. Let me know if this helps.

 

Thanks for all the replies! I'm not going to be able to work on the car until next week, but I'll check all of these and see what I've got. Looks like I have plenty of places to start the search now!

Thanks again and I'll post what it was when I find it.

 

Did you find the cause of the rattle yet?

 

I found that the i-pipe had expanded a little allowing the y-pipe to rattle against the inside of the i-pipe.

I used an exhaust pipe expander to expand the y-pipe so now it fits snug inside the i-pipe.

 

Are there any side effects to removing the panhard bar? My damn exhaust is riding on it and im about to rip out the bar.

 

I think so...I'm gonna take it out in a little bit and see. After checking everything listed here I got a better look at the heat shielding and it looks to be the culprit. One of the screws was missing and it looks like the shield was contacting the over axle pipe and since it was a little loose I think it was vibrating. I'll post back and let ya know for sure.

 

i was having this same issue and found the same problem, the screw wasn't hella loose but it was 3 turns loose and was lettin the heat shield have some play. hopefully this fixes it for the majority, i'm puttin brand new shocks and coils on by spring time so the ride will just have to suck until then lol

 

i found my issue my exhaust pipe is hitting the top portion of my rear end so it's either put stock springs in or do something with the exhaust to make it work