What is making this darn rattling sound????

chrisbruck · chrisbruck's Garage

I can't for the life of me track down an annoying rattling sound coming from somewhere behind me on the drivers side while driving. Been doing it for a while but much more annoying with the colder weather and windows closed. It's a light "rattling" sound directly related to the speed I'm going. Sounds EXACTLY like a noisy speedometer cable but it's coming from the back of the car somewhere. It's NOT a groaning sound like a bad wheel bearing much a much lighter rattle sound if that makes sense. It does get a little louder as I speed up. It does NOT change no matter what I do while driving. Definitely a "rotational" kind of noise.

Corner hard left or right, no change.
On the brakes off the brakes, no change.
Parking brake on or off, no change.

I've pulled the wheel off, inspected the parking brake parts inside the hub and nothing seems amiss. The CV joints seem tight and "normal" to me. Looked all over under the car for loose parts and found nothing obvious.

What else could I check? Could it really be the CV joint? Sounds too "light" to be that. Could something in the transaxle be loose? Again, it's a light rattle and not a groan or heavy grinding sound. Just a light rattle.

Ugh, please help. It's driving me crazy.

redridge · 11-24-2013, 05:24 PM

is the CV boot leaking or torn?

chrisbruck · chrisbruck's Garage

Nope, the boots are in good shape with no tears or leaks.

pors1968 · pors1968's Garage

check around the cat for pièces rock or thin broken.hit it whith rubber hammer.

schulr · schulr's Garage

How's your clutch working. The G 50 has some issues with the fork and the roller bearings. My fork actually broke and cause a lot of collateral damage but it made noise beforehand. Just a thought.

Bob

crownarch · 11-24-2013, 06:49 PM

Might be, could be, but carefully open the zipper on your headliner and feel around under the foam for the Phillips head screws. Check to see if they are tight. Had that happen on mine and it drove me crazy as the rattle was behind me and sounded like it was coming from the engine compartment.

irobertson · irobertson's Garage

Make sure the bolts that fasten your inner CV joints to your transaxle are tight. If they are loose and work their way out, the axle will do considerable damage as it flails about.

chrisbruck · chrisbruck's Garage

It's not the clutch.... played around with it on my way to work. No change in sound while shifting gears, clutch in, clutch out....

I did notice there is a slight change in sound when turning slightly left vs slightly right. Seems a tad louder turning slightly left but barely. It's got to be something with the axle or wheel bearings since it's directly correlated to road speed.

The weird thing is it's just a light rattly sound and not a coarse groaning sound I would expect to hear from the wheel bearings or CV joints. Again, it sounds EXACTLY the same as a noisy speedometer drive cable that I've heard in other cars.

chrisbruck · chrisbruck's Garage

It's not the clutch.... played around with it on my way to work. No change in sound while shifting gears, clutch in, clutch out....

I did notice there is a slight change in sound when turning slightly left vs slightly right. Seems a tad louder turning slightly left but barely. It's got to be something with the axle or wheel bearings since it's directly correlated to road speed.

The weird thing is it's just a light rattly sound and not a coarse groaning sound I would expect to hear from the wheel bearings or CV joints. Again, it sounds EXACTLY the same as a noisy speedometer drive cable that I've heard in other cars.

daleflesburg · 11-25-2013, 06:31 AM

Is the rattle in the door? Is it different if the window is up or down? I had a strange rattle. It would rattle with the driver side window up. It would not with the window down. I finally found that a bracket that secures the forward window channel at the bottom of the door was loose and would rattle it the window glass was up and not supporting the channel.

chrisbruck · chrisbruck's Garage

Quote:

Originally Posted by daleflesburg

Is the rattle in the door? Is it different if the window is up or down? I had a strange rattle. It would rattle with the driver side window up. It would not with the window down. I finally found that a bracket that secures the forward window channel at the bottom of the door was loose and would rattle it the window glass was up and not supporting the channel.

My door does have the same rattle but the other rattle I'm chasing is different.

kodioneill · kodioneill's Garage

Additional air valve? Did it start/get worse when cold? Sounds like a buzz will go up and down with throttle. Do a search and see if it corresponds with your problem.

realgren · realgren's Garage

A little basic, but are your rear seats folded down?

Sometimes my seats rub on the seatbelts and make a rattling noise.

chrisbruck · chrisbruck's Garage

Quote:

Originally Posted by realgren

A little basic, but are your rear seats folded down?

Sometimes my seats rub on the seatbelts and make a rattling noise.

Yup, checked these.... this was the first thing I thought. What I really need to do is make my 10 yr old drive and I stuff my 6'-0" frame in the back seats to narrow down where it's really coming from.

I've looked all over the car for loose items. Amazing what all stuff I did find but nothing causing the rattling / clicking I hear.

The sound corresponds to rotational speed so I really think it's something in the driveline.

awdbandito · 11-25-2013, 11:06 AM

I had an unusual rattle coming from the engine bay that I only heard at low RPM. It was pretty loud though and could be heard by hand rev'ing the engine inside they bay.

It was a failing/failed hydraulic timing chain tensioner.
Not sure it is what you are describing, but worth a listen with a stethoscope.

Josh D · Josh D's Garage

I had a rattle that turned out to be the chrome exhaust tip had come loose of the muffler. Something easy to check.

718 · 11-25-2013, 01:13 PM

Take all 4 wheels off and rotate them while listening and check for any trapped rocks.

Also, what happens in neutral while cruising? What if you turn off the motor while cruising?

Laneco · 11-25-2013, 03:51 PM

I've found the following items in 911 engine bays...

A socket. Not one of ours, it was not the brand we use so it was definitely previous owner.

Shims for the alternator - hey THAT's why the car only had 5 when I bought it -LOL!

A small flashlight - okay...it was pink so pretty obvious that it was mine.

Assorted small fasteners and one time, a grommet like the kind you use on a garden hose. Weird.

Most of these did not make any noise at all but the socket would on bumps.

angela

porsche930dude · porsche930dude's Garage

i wouldnt rule out the parking brake. could still work fine with something wrong. if it were the axle i would think it should change with the amount of power applied

kodioneill · kodioneill's Garage

Quote:

Originally Posted by porsche930dude

i wouldnt rule out the parking brake. could still work fine with something wrong. if it were the axle i would think it should change with the amount of power applied

I have to agree I had that same issue a while back. Jack the car up one side at a time and block the front wheels be very careful but you can fire up the car and have someone go through a couple of gears, listen and look underneath if it's the cable/parking brake you'll see the cable rattling around. If it's the parking brake the shifter will usually vibrate too.