Hi Everyone!

This is my first post on the forum. I have a 2000 Infiniti I30t w/106k miles, automatic transmission. I last serviced the transmission with a drain/fill 8 months ago with some Nissan ATF. I checked the fluid, color is perfect, the level is perfect as well.

For the last few months I've been hearing this weird noise. I've recorded it and uploaded to youtube, check it out. I hear the noise during the following scenarios, and have listed some other symptoms as well.

http://www.youtube.com/watch?v=asUXC...ature=youtu.be

1. Cold start car, while engine warming up, noise will come randomly in idle.
2. (youtube video scenario) Cold start car, if I shift between park, reverse, neutral, and drive, in any random combo P to R or P to D, etc, the noise will be replicated immediately during or after I shift. What I did notice though, is if I shift between D, 2, 1 (any order) , the noise will NOT take place.
3. Driving car at operating temp, and as I press the brake slowing down, just as I almost reach a complete stop, I hear the same noise 1-4 times in a row, but then NO noise after I actually STOP the car.
4. If I start the car on a warm engine ( after I had just been driving for a while at operating temperature), and I repeat #2 above, I DO NOT hear the noise at all.

Any ideas? Maybe its not the transmission at all? Something else? I appreciate the help guys!

 

I wonder if it has anything to do with the belt...
Stretching even further, maybe motor mounts...
Hopefully someone else will chime in.

 

thanks for the advice. I'll check out the belts and engine route. Anyone else have any ideas?

 

I'm thinking something in the brakes or suspension. It seems like it happens when the car lurches against the brakes when you put it in gear and again when the car "relaxes" when you put it in neutral.

The coil springs sit in plastic insulators and if they have worn out the ends of the springs can do metal-to-metal rubbing. For the brakes to make that noise, something would have to be loose, or maybe the splash shield is bent.

 

Thanks for the comment, but can this theory explain the noise taking place during idle in P? And why does this noise only take place when shifting on a cold engine, not hot? With that said, I'm pretty sure my suspension needs to be replaced, I feel every little pothole on the road but not sure if it's causing this noise.

 

If the engine doesn't idle smoothly, it might be possible but I wouldn't bet too much money on it. Maybe it's a motor mount doing it. As to why it happens only when cold, I have no idea. Sometimes problems only happen at a certain temperature. Sometimes problems only happen in certain geographic areas. Beyond me.

You may need new struts. They help smooth out the bumps in the road. So many people ignore them. Struts need to be replaced every 80 to 100K miles, depending on your roads.

 

I am new to this forum, just read all replies and was wondering if you were able to determine and fix the problem, I think I have the same condition and can't determine where to start.
Thanks so much,