jtsporsche

at about 30 mph and up i hear a metal rattling thats louder when i hit the gas.
i checked the exhaust and the heat shield around the catalytic converter, its all bolted down tight. any suggestions?

JWM944

I have a rattle at around 2700 rpm regardless of speed or gear. I can't seem to track it down either.

V2Rocket

My entire car rattles like bearings in a can.

Check the rubber exhaust hangers; they harden over the years and make all sorts of noise.

Weston

I recently developed a similar problem... after a weekend at the race track, where I took a few trips into the dirt, I now have a heavy rattling from the center tunnel, around the bottom of the firewall, right around 3000 rpm when moving. It doesn't do it when I rev the engine while the car is stopped... only when moving, and it goes away at higher RPMs. I crawled under the car and didn't notice anything loose or bent.

austin944

I had a similar problem, it turned out the CO test pipe had disconnected from the exhaust and was rattling around. Also made a rasping sound due to the exhaust leak under acceleration. The test pipe connects to the exhaust near the O2 sensor.

TRP951

starter heatshield probably is cracked at the mount

KLR

I used to have a similar issue at around 2-3k rpm or occasionally when starting from stop. As you might guess, it was really a combination of about 4 things that added up to a cacophony. Every time I fixed one of the culprits, I could hear the next and work on that. It required a lot of patience. Every one of these rattles was a heat shield. There are more heat shields on the 951 than an N/A, if that's any consolation.

My gremlins were:

1. Rattling cat heat shielding.

Resolution -- I just pulled the heat shielding around the cat off entirely. There was no welding this back on, as it had really started to disintegrate. Interestingly, being without cat heat shielding did not impact my ability to pass emissions (i.e., that cat stays plenty hot). I suppose that this may have increased the likelihood of fire if I parked on a pile of leaves or some such thing.

2. Heat shield between the headers and oil filter housing rattled because the bracket that it mounts to needed to be rewelded. This was a very noisy one and probably 75% of my problem. I think that this may be a 951 only piece.

Resolution -- Had this rewelded when I replaced the headers.

3. CO2 test tube was left unattached to the bracket at the back of the motor and was (possibly) rattling.

Resolution -- Cut the tube down by the base and put a bolt in it at my wrench's suggestion. I don't really think this was making much noise, if any.

4. Starter heat shield was missing a nut. I think that this starter heat shield was 951 specific.

Resolution -- Replaced nut. This was a MAJOR evil-doer and finally gave me peace and quiet after I fixed it.

Not surprisingly, I now have a very modest rattle coming back that I heard for the first time this weekend. I hope it's not the weld to the shielding under the headers giving up, as this is the one issue that is not easily put right.

mzman

Bringing this one up from the dead.

I am hearing a buzzing/rattling noise from 1900-2100rpm it happens if im driving or just sitting and rev the engine.

So i am going down the list of possible things, and gotten to the heat shield between the header and oil filter, and when I try and wiggle it with my hand it feels very solid. Could it still be loose and making the noise? Or would it move around easy?

I just replaced the exhaust with LR 3" so I know its not the cat.

Catfood

My dad had a similar problem on his car, it turned out to be some loose metal in the catalytic convertor

mtccl

Mine was the heat shield between the exhaust manifold and the oil cooler. Horrible vibration at 4k rpm.

Also had my O2 sensor come loose one time and it sounded like marbles in the catalytic converter.

krystar

most of the time, an engine resonance rattling can be duplicated with the car on jacks and just running the engine at that rpm. it'll take a second person to do it.

i had rattles on muffler heatshield, flywheel inspection cover, a little D ring in the hatch for.....trunk net or something, rear taillight bulb cover.

ATL944

I've got the same problem, I hear a buzzing noise at low rpm's and idle. My mechanic told me the vibration was coming from inside the cat and not to worry about it until the catalytic converter went bad.

mzman

I just replaced the entire exhaust system with new cat, and everything is down tight.

But while looking for the buzz, I noticed that I am missing one of the two large bolts that hold the start heat shield on. Although its still very tight I think that missing one could be my problem.

KLR

That missing bolt on the starter heat shield is almost certainly part of the problem. I was missing one of the two little nuts on the back of the heat shield. The shield felt plenty tight when you grabbed it, but replacing this nut made a huge difference.

On the oil filter / header heat shield -- in my case, you could feel that it was loose by grabbing it.

atwong1

I know we all love the roar of our engines, but those annoying rattles and noises? Not so much. As an owner myself, I understand how even a small rattle can disturb the joy of the ride.

That's why I put my engineering background to use and created an easy-to-follow guide on how to find and fix those pesky car rattles. It includes a unique set of vibration simulation mp3 files - free to use for everyone. You can simulate the necessary vibrations without having to drive around, making it easier and safer to locate the source of the rattle.

Trust me; you'll love the peace and quiet on your next ride. Check it out! https://9xx.com/products/9xx-vehicle...tion-mp3-files