I know these posts are common, but I've read through hundreds of them on this forum and am also growing frustrated at the number of videos (ticking noise videos) that have been taken down. I can't tell what the sounds they're discussing actually sound like. Anyways...

I have a 2004 350z Touring, non-rev, automatic transmission, with 115,000 miles. I purchased the car only about 7,500 miles ago. It has a noise I would describe as more of a knock, and it seems to be getting worse with time. This has been going on since about a month after I got the car. I don't drive it hard, though, & I've done oil changes (10w-30 in late summer, & 5w-30 over winter) & monitored oil levels (as best you can with this friggin dipstick). Oil pressure reads fine & is acting normally.

Car is stock. Check engine light is NOT on, and no codes thrown when I last had it looked at (was 2 mos. ago).

Symptoms:
1.) Knock/ticking noise heard ONLY on idle. If engine is revved, noise goes away.
2.) Noise heard only AFTER driving car. Not necessarily just when warmed up -- if car is started and left on idle, there is no noticeable noise, even after car is fully warmed up.
3.) Noise heard only in park, reverse, & neutral. If I put it in drive, noise goes away. I haven't seen this symptom on any boards...
4.) Cannot be heard from inside the cabin, even with radio & AC off. I can sometimes hear if I roll window down
5.) Mechanic didn't put car on lift or use stethoscope, but said noise appears to be originating from the bottom of the car, behind the engine, on the driver's side.
6.) Noise loudest/heard best when listening from front driver's side wheel well, and when the hood is open
7.) Noise doesn't always occur, & sometimes it is louder than others. Typically it is most loud if I have been driving at higher speeds (interstate).

UPDATE - VIDEO ADDED:

Different issue or related?
Tonight I was driving home and when I accelerated from 25-45, the transmission slipped (first time I've noticed it happen), and then it did it again later on. When I got home, the knocking noise was probably the loudest it's ever been, and could be heard throughout the entire bottom of the vehicle. There was a smell which I thought smelled like rubber wearing on something. The exhaust wasn't smooth, either, and there was a faint smoke coming from the driver's side exhaust pipe.

Solutions?
Up until today I was convinced that it was the fuel dampers, but now I'm becoming very concerned that my transmission is going on me. I am going to change the diff & transmission fluids tomorrow and see what that does. I have several ideas of what I think it is, but some of these fixes would cost me $100s-$1000s so I can't really afford to just try random fixes and see what sticks here.

I'll try to have a video posted within next 24 hrs. I went out to take video & there was no knock... The really bad knocking was only about 4 hrs ago.

 

Nobody?

This may sound crazy, but do you think there's a chance that I'm not driving it hard enough? I almost never hit over 3,000 RPMs when driving, and drive mostly around town, 4-5 miles at a time. Yesterday, my mechanic had me drive it 'hard' up and down the road, and when I returned, no ticking sound at all???? I was hitting over 6,000 RPMs on acceleration.

One thing of note - when accelerating, it takes some serious acceleration to get it to shift. If I get up to speed (say 50MPH), and the RPMs are high, and then I let off the gas without it shifting up, the car will coast for a second, then it will feel like a controlled slowdown (like a downshift feels, but I'm not sure if that's what is happening since you can't see what gear you're in when auto is on), and then there is a very harsh 'jump' feeling.

The strangest thing of all is that after driving it hard (which was only for about 5-6 miles), the car felt like it had more power when I drove it back home. It felt like my foot on the pedal had a more direct impact on the speed of the vehicle, if that makes any sense.

This whole thing is just incredibly confusing and frustrating. It has been making the noise after every time I drive it for months now, and it sounded the worst it ever has just a few days ago.

 

You need to post a video with audio. Film from front bumper and hood up,running with symptoms.

 

Hi JHC,

Yes, I agree. The only thing is that it wasn't ticking yesterday like usual. That's a good thing, but it's extremely frustrating because it's been ticking after every single time I drive it for the past 6+ months. Why it suddenly stops when my mechanic finally gets it on a lift, & I post on the forum for help, I don't know...

I do have a video from yesterday and you can hear a clicking type noise, but it's faint. Typically the noise is much louder, distinct, & truthfully it just sounds a bit different.

Either way, I am attaching my video from yesterday to post #1 - hopefully this gets the ball rolling with a diagnosis! Will upload a better video soon.

 

One of these dayz i'm gonna fix my axle clic...gl

 

Can't tell if throwing suggestion or being a jerk?

Do you really think it's an axle click? I know that's a common issue with these, but symptoms don't seem to add up for the axle click (AFAIK). Namely, there is no noise when accelerating - sound occurs only when idling, and typically only when in P, R, or N (& not in D).

 

No,, it was a random comment. Just trying to keep you company till help arrives.
It also bumps yer thred up so people see it...

 

i listened to the video last night.... and cant tell crap from it. but, at the same time it kinda sounded a bit like an exhaust leak to me.

 

I'll listen to the video tonight.