At around 1-1.2k rpm a loud rattle can be heard from under the car. It only happens when I pass or hold this rpm range. Also, it only does it when the car is in gear. If I rev in neutral through this range no sound at all can be heard (which makes me think it's the tranny). The strange part is, once the engine is up to normal operating temp the sound goes away all together. Is anybody else experienceing similar problems?

 

Is it a rattle or is it a rumble? The rumble is normal, and it means ur shifting too early.

 

More of a rattle. It doesn't happen when I shift though ... the sound occurs anytime I hit that rpm range while still in gear. It only seems to happen in 1st as well.

 

Could it be exhaust pipe vibrating against something?

When you rev in neutral, there is no load on the engine so you don't get that small amount of twist from the torque. That twist could be shifting the cats or Y-pipe enough to rub or vibrate on something.

 

Exhaust system.


The temp change makes me think it is that.

 

If its a rattle chances are its either something in ur exhaust system hitting something else.. how old is your clutch btw?

 

15k miles

 

I also have a rattle in that range in first. It only seems to happen when I let the clutch out to fast with out enough gas, is this normal? Mine is not my exhaust I know that, I had mine inspected over and over for a rattle I had in the 3k range. Warm or not my car makes this noise as well.

 

I had that rattle when you release the clutch checked out last week. The mechanic said it was just the tranny under load, and it's more pronounced in the Z than other Nissans. I also tested out a couple of new Z's and they had the same noise. If we're talking about the same thing than it's normal.

I'm not sure about the original poster's noise though

 

Ya sounds like the same thing, If I feather correctly there is no noise. Its just happens when the clutch comes out to fast with out enough gas. Thanks for the info!