2000 C2 with annoying exhaust tip rattle

I have a 2000, 996 C2, 6 speed with an annoying exhaust tip rattle at idle "only when it's hot" I have had it running on the lift and the muffler and Cat don't appear to be the cause. Any thoughts? it's on the drivers side tip and if you place your foot on it or hold it with a towel etc. it quiets right down. I have checked the muffler support mounting bracket and the 3 bolts are tight and removed and re installed the tip, can a tip have a broken weld that would result in rattling when hot ? I've looked around on the forum and see lots of bad mufflers and cats and was looking to see if anyone had a similar tip problem. Please help point me in the right direction. Car has 50K miles on it and other than the annoying rattle it runs perfect... Thanks, Matt

There is a TSB out on this, number 9/02 2634 but it may not be applicable to your year. It is an easy fix, it adds an additional washer on the stud between the tailpipe cover and the tailpipe. Try that and see if it fixes the problem.

Take it into a Jewish garage. They will take a couple of inches off the end of the muffler for you haha.

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+1 You beat me to it. The TSB is posted over on Renntech. Good lord, that is an annoying rattle!

I had the rattle ... Bolt on tip was pretty rusted .. Some wd40 ... Reinstalled bolt ... Fixed the problem ...try a new bolt and two washer fix ...

i have same problem. can someone send me the link to whatever TSB is? What bolt? R u talking about the bolt that goes into the tip from the bottom, which i have taken out & reinstalled several times? thanks as always- m

If you do have some info for lingpoen please post it in the thread so I can see it as well Thanks for all your suggestions, Matt

Yes it's the stud on the bottom, that holds the tailpipe cover to the tailpipe. There should be a bolt and washer on the stud. The TSB adds another washer between the cover and the tailpipe. That's it.

Do the early year 996's have the stud on the bottom that holds the tailpipe cover to the tailpipe? I have found a photo with what your talking about but mine has no stud or nut, is the tip welded on, if so can you loose the weld?

Matt: Under my tip there is a hole to where a bolt with a long spacer & nut tighten around a clamp inside. Also, there is a flange running from insdie the tip to another clamp around the muffler that i must have grabbed a 100 times & banged on to see if it was loose..it was not. However, 2day i finally just took it off to learn it was sheared at the other end inside the tip, jiggling around in there driving me nuts. Problem solved. I may go get another flange, i may not. Picture of clamp & flange....hope this helps.

Thanks for the photo, glad you found the source of your problem but my 2000 does not have that bracket or clamp on either side. My tips look to be original and have the # EP4110 stamped into them. No stud or bolt to add the washer fix, I'm assuming that he tips may have changed as the model year's progressed? The rattles is at the tip, I'm thinking a broken weld or something loose "or worn out" but everything looks tight with he exception of the rattling tip... it's enough to drive me crazy Thank you all for your help finding my gremlin, please keep the suggestions coming. Matt

I suggest you remove it from the muffler and bench test it. See the photos here http://forums.pelicanparts.com/porsc...haust-tip.html It extends up a bit and is attached to the muffler by a big clamp.

Thanks Ahsai, I've removed the tip and it looks good, it's hard to bench test it as it only rattles when the car is at operating temp. I'm wondering if it could be a broken or cracked weld on the tip. With the car up and running on a lift the noise is just from the tip, listening to the cats and muffler they all sound the same on both sides. I simply love the car and will do what ever it takes to find the source of the rattle... Thanks, Matt

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Sorry I missed that you've already removed and reinstalled your tip. So with the tip removed, are you sure you don't have rattling when the car has warmed up? If it's truly the tip, I suppose a loose weld that opens up only when hot is possible. If you have examined the tip carefully already and still can't locate the source, can't think of a solution other than swapping it out with a new/used tip. Should be easy to source from junkyard for cheap. How are your motor mounts? Maybe new mounts can shift the vibration freq just enough to quiet the tip.

I was thinking along the same lines, I ordered a used replacement tip on eBay, I'll keep everyone posted Do motor mounts go with mileage or age? or a mixture of the two? I just turned 55K miles... Someone suggested it could be the isolation bushings on the muffler mount, but looking at that part "The one the muffler bolt's too" it doesn't look like that would fail, anyone have problems with the mount? I'm open to all suggestions on how ro fix this problem so if anyone has a different path for me to follow just point me in the right direction... Thanks again, Matt

Those bushings are made of steels (like steel wool brushes) so i don't think they will fail. If you're so sure it's the tip itself, the replacement tip should fix it unless it's defective too. My engine mounts were replaced at 28k miles when the car was only 3yrs old (no leaks but could feel the engine vibration more). They have fluid inside and deteriorate in time and mileage just like suspension. The vibration was much less and it felt like I got new rear shocks after they were replaced.

Thanks Ahsai, Will start with the tip but I do see a little vibration on the tip, just on the drivers side, perhaps the motor mounts need replacing as well. Looks like an easy job. I will report back and let you know once I get time to change the tip and perhaps the mounts as well. I have seen the muffler bracket off a 996 and agree I don't think it's a wear item. I will replace both mounts but as a rule dose one fail before the other? Thanks for your help Matt

I went through the 'exhaust rattle Easter egg hunt' with my car too. For those on the hunt for the rattle: 1. Could be loose tips, try tightening the bolt which holds the tip in place. 2. Could be loose c-clamps where the cat pipes attach to the mufflers. Tighten those. 3. Could be loose where the manifolds bolt to the cat pipes (3 screws, tighten those, check for gaps) 4. Could be a heat shield touching up against something, check those from under the rear. 5. Could be one of the clamps that holds the cat pipe to the bracket that mounts to the car. Tighten those. 6. Could be, and this is what it was in my case, a slightly loose O2 sensor, with a washer rattling around. Try tightening both O2 sensors (or all four if you have them). In my case, I swore it was coming from the tips. I got down on the ground and listened, and could only conclude that it was coming from the tips, or somewhere around the tips. Turned out to be a loose O2 sensor. Hunting for rattles is easier with the rear bumper removed, it's only a few bolts, give it a try. Happy hunting.