Grinding Noise Between 2K and 2.5K RPM

CupDeJoe

Hello Guys,

I bought a full FI Exhaust System from a member (Test Pipes + full CBE) a couple of months ago. The exhaust was installed professionally and all was going well, but about a month or so after the install, I started hearing a grinding noise between 2K and 2.5K RPM. The grind sounds like 2 swords/knives sliding against each other. I've been super busy so I haven't gotten to post this until now. I took my car to 2 shops and nothing is hitting the exhaust system (no loose heatshield) and bolts and install are clean and tight. No leaks no cracks, nothing at all. I'm getting tired of the horrible sound and I'm hoping someone here might have any idea of what it may be. I have searched several times and even searched 350Z forums to see if anyone had anything similar, but most threads didn't lead to a solution.

Thank you in advance for any feedback!

Quicksilvers

It is hard to diagnose a noise over this site and it would be best if a reputable shop or even your local Nissan dealership service department perform this work. From how you described this issue with your Z. Depending on where this metal grinding noise is coming from on your Z? It is possible one or both of your wheel bearings is going bad. Wheel bearing failure is a common problem on our Z’s. Also you could have a bearing in your rear end that is going south it can happen at any mileage. Something can be rubbing against your brake rotors as they turn when you are driving. Do you keep up with all your general maintenance on your Z? Have you ever changed your differential fluid? Without hearing this noise in person it will be hard to diagnose here. Give us more details about your Z.

redondoaveb

OP. It appears you're in Torrance. Have you taken it to Alex at L Spec? I'd be surprised if he couldn't isolate the issue. He's done all the work on my z (and I've had a lot done), including the install of my FI cbe.

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Crevi

I have the same problem, in my car was the test pipes resonator. Some welding inside has failed. I found him hitting with a hammer until I found the focus of the noise.

The noise appears if you accelerate with the car stopped?

Spooler

It could be the hub springs on the clutch rattling. I have the same noise every now and then. That's what it sounds like to me.

CupDeJoe

Quicksilvers, agreed it is pretty difficult to diagnose a sound over the site, but I am at a point where I need any help or possible advice I can find! I don't believe it is a wheel bearing issue, the car is a year and a half old with only about 8K miles on it. I can always take a look, but I certainly hope the car isn't crapping out yet. I have kept up with the maintenance, but no changes in fluid past the oil. The time I started hearing it was after I swapped the exhaust system so logically I would think it may be the exhaust creating the noise

Redondo, I am in Torrance, I went to 2 exhaust shops to take a look at the system, but never really thought about going to L Spec. I'll put some time aside to reach out to him!

Crevi, what system are you running? Were you able to get rid of the noise or is it still around? We were banging on the mid-pipe and test pipe area and it made a louder sound, kind of like what you're describing. I usually hear it whenever I am between 2 -2.5K RPM, anything lower or higher I don't hear it.

Spooler, I'll take a look at the hub springs as well, but do you hear the sound at certain RPMs or through the full power band?



Thank you all for your input by the way, I really appreciate it!

Spooler

I only hear it around the RPM range you describe. My engine will be coming out in June and I will have a chance to look at the clutch disk. If I pull the pressure plate off I should be able to tell very quickly if this has been the sound that I heard.

Crevi

Before i had a megan racing test pipes, now invidia no resonated. The noise has gone.
If you have FI test pipes i think they are resonated, it could be the same problem

The noise coming from the clutch I think is softer and starts at less rpm