Little background, had the trans rebuilt and new clutch/flywheel/pp/pilot bearing/t/o bearing 8 months ago, car ran perfect. Realized today that it makes this odd *** rattling noise. It doesnt do it when the cars cold, and won't do it if you baby the car and shift at like 1,500. But once you hold out a gear to like 2,500 or so and the cars warm, or if you put some load on the engine this wierd rattle will start which doesnt very with rpm. If you stop the car and rev it w/ the clutch in or out it will make the rattle once you let off the gas while reving. It tends to make it most often and the worst when letting the car ride out in a gear such as a first until 2,500 and letting off the gas and letting the car down rev. Sounds like a loose exhaust bracket but its not, since we went under the car and hit every with a mallit to try and emulate the sound but couldnt anywhere.

Now the odd part, once it starts to rattle it will do it for a bit, then sometimes just stop and you won't hear it again until you put more load on that car. When it is making the rattle noise while reving it in neutal once you rev it a lot maby 10 times it tends to stop making the noise, and will not start again until you do what was described above. Very wierd. Please help and suggestions welcome.

Cats are hollowed out so it cant be them, I took the dust cover and slave cylinder encolsores off the bell housing couldnt see anything broken but who knows it could be trapped inbetween the clutch and pp. If something did break in there wouldnt it be constant? It seems to come more from the passengers side from the center of the car.

 

I think I know what the noise is you are talking about. It sounds like a noise that you never heard in your life or at least in your car before right, like a gurgling/grinding/rattling noise at the transmission. Well I had that same noise right before my catalytic converter totally broke, and was being caused from the exhaust not being able to pass through properly causing a lot of heat coming from the cat, baking the hell out of my transmission. Removed the cat and ran straight pipe. No problems and noise gone. Now I just upgraded my muffler and it flows nearly 3x more than my old muffler and the noise just returned(when the car is cold like first minute of driving it is fine but the longer you drive the noise gets progressively worst especially over 2500pm range. Although the car drives fine but It is probably the oil getting extremely hot. Just bought a 2ft Thermo tec clamp on heat shield(advertises 98% heat blocked) and will be putting it on today when it comes. I'll let you know if the noise goes away and it should. I noticed you said you have hollow cats. Did you just have those put on because that could be the problem now because more exhaust is going through. I am no car wizard but I'm just telling you from my own personal experience. I will let you know what happens today when I put the heat shield on. Laterz
-Shane

 

Check out the heat shields on your passenger side. There's a joint where two of the shields come together and it's possible that they may be rattling on one another. It may be it, it may not be, but it's worth a shot.

 

Thanks for the tips, I didn't hollow the cats out but some previous owner did. It would make sens that something it clogged cuz my oil is getting damn hot. I have a fram oil filter and that charcoly black rubber thing on the end started bubbling.

My dipstick was hot as **** too, when I took it out to check the oil. I dont know what could be clogged in there? The other wierd part is when I bang on it I can't get the noice to come back.

 

I tried bending those a little. Maby I will remove them, I'm droppen it off an a shop which did exhaust work in the past for me hopefully they will be able to figure it out.

 

well turned out it was a peice of cat jammed between the 2nd o2 sensor and the pipe, couldnt get out.