Weird "Rocks Rattling in Can" sound?
 

Hey guys,
For the past 2 or so weeks, my vette has been making this weird rattling sound (like rocks rattling around in a tin can) when the car passes 4k rpm and the outside temp is below 45. Any ideas?
The sound is coming from directly below the center console :sad:
My cousin had a similar issue on his camaro and it ended up being the differential :eek:

Auto or stick? Missing any pets? :D

U-Joint?

Clogged or breaking up cat converter? Could be almost anything.:thumbs:

could be a broken heat shield around converter...or someone stuck a can full of rocks under there;)

Its your big cat comming apart inside

Corvette Mike

:iagree: Thats what mine sounded like when it was coming apart inside...WW

If you had hub caps I'd say..........i used to do that when I was a kid to my friends. Surprising how long it would take some of them to figure it out.

I forgot to add, it IS an auto, AND on 2 different occations, when I've punched it when it was cold outside, the rpms rose significantly, but the car didn't gain speed. It was almost as if the teeth had been stripped off a gear...

ohhhhhhh, it's the trans.
It's like a shudder with the thing shifting into a lower gear, then unable to shift up at that engine speed.
my 86 had that. the 700r4 is a 4L60E with a different valve body

Ya that's exactly what it did! What needs to be fixed/replaced?

you need a trans rebuild.

You can't be serious? It was JUST rebuilt!
:mad:

:iagree:

How can I check to see if this is what the issue is?

You can hit it with a rubber hammer and listen for a rattling sound inside there. If you have the stock mufflers they can also come apart on the inside. If I have mine in neutral and rev the engine I can hear it.

Jason,

Didn't do anything when I revved the car

I'm thinkin it might be a heat shield. Btw, got my x pipe installed today and saw that my right 02 sensor was dangling next to the cat. That explains the CEL and possibly explains what the noise was lol

LOL...Yeah..that would probably explain the rattling...:leaving:

I found what the issue was!
While having the x pipe welded in, I noticed that all of the bolts on the bottom of the tranny were about to fall out (LOL). I screwed them all up tight and what do ya know, NO MORE RATTLING!!!!!!!!

:cheers:

I told you it was the trans..........just I wasn't there to hit you with the hammer for not looking at it better!!!
:smash:
:lol::

Lol, I got to looking at it, and I was like,"WTF, these bolts go to the tranny. Why the heck are they 6 turns loose?"

:rofl::rofl: Excellent :cheers:

I vote for clogged converter. For a converter to be plugged it typically means the O2 sensor is bad and it should throw a code.
93cruiser

It actuallu rattled for the first time in a while last night. I'll check to see if those tranny bolts came loose again. My right heated o2 sensor is unplugged, and I can't find where it plugs into, so that could be the issue too. Or the exhaust is just rattling against the underside...

With a faulty or unplugged O2 sensor the computer sends more fuel to that side. Your exhaust should be foul smelling rich on that side and your car should run like s**t. This rich fuel mixture will plug the converter. This happened to me with a faulty sensor. The convertor guts finally let go. I guess I got lucky that I did not get blow by on those four cylinders. Sounds like you cat guts are coming out as well. You need to plug that sensor back in.
93cruiser

Where is the harness that it plugs into? NO ONE has known where it is

The plug is sitting on top of the starter. It is very hard to find unless you move the plug to an accessible place prior to installing the starter. If you can't find it, that means it fell between the starter and engine block. Take the starter off and you should see it. I know it is frustrating because I had do that very thing. I learned quick to position that plug during the starter install.
93cruiser

Just reread your post. You said heated sensor which is the one past the converter. I was telling you where to find the sensor connector before the converter. The wiring for the sensor past the converter should be easy to see unless it is missing.
93cruiser

Sry, u were right, it's the pre cat one. Thanks for the help!

How do I remove the starter :o

Safley raise the car so you can get under and work from beneath. You need plenty of room to do this. Disconnect the negative battery cable. Using a small 1/4" drive socket set, disconnect the power cable and the small solenoid power cable. Do this the first. Then you can remove the two starter bolts that secure it to the engine block. Hold the starter as you loosening the bolts. It is heavier than it looks.
Hope this helps.
93cruiser

Thanks! I'll go fix it now

UPDATE:

had such a productive day. Fixed my oxygen sensor, bought a new thermostat and installed it, fixed the heater, and replaced the antifreeze with the RIGHT stuff (it had red antifreeze, it NEEDS green). And I figured out what the clicking was: when my ignition coil gets wet (humidity/rain/whatever), the car misses. I must just be living right...

MY MILEAGE HAS COME UP FROM 11.5 TO 21.3!!!!!!!!!!!

no, you are just bumbling around and there are no sharp objects in the way:lol: