Rattlesnake sound above 2.5k
 

Alright so, a few weeks ago, I started to notice a rattlesnake sound coming from the outside of the car. At first, I thought it was just brake shims that were rubbing on the disk and making that sound but, turns out, it's linked directly to the engine's RPM.

From what I've noticed, it seems like it's not as intense when the engine oil is at around 90c or above.

Any idea what that sound could be? What should I check?

Most importantly, IS MY ENGINE OR TRANS GOING TO BLOW UP?

I had a rattling noise coming from my Z a few months back. It would not do it cold but got progressively worse while it heat up. I got under the car and with a mechanic’s stethoscope found the sound coming from my passenger side cat. It struck me odd since the car had ~39~40k miles at the time, but I took it into the dealership and they replaced it under warranty. You have 8 years warranty on the cats.

Considering that it gets better once the car is warm, it doubt that it would be the cat. It really sounds like something metalic rubbing against each other.

If it's happening when the car is not moving, have someone operate the gas pedal while you locate the source of the sound. There are a lot of moving parts inside the engine compartment that can hurt you - stay away from them. Use a mechanic's stethoscope, piece of garden hose, etc.

Firstly, what engine oil (viscosity and type) are you using. If you don’t know then change it immediately to a good 5W30 synthetic. The engine’s VVET system is known to make slight rattling noise. Good synthetic oil should help. Or you can try the Nissan Ester oil which was specially developed for our engine to reduce the noise that the VVET can make.

Second thing that can rattle is the clutch. Try revving with the clutch depressed. If it goes away, then it’s the clutch and you’ll either learn to live with it or change it.

I would start with that. By the way, both of those items are no cause for alarm. They’re just annoyances you get from a high performance car with little to no sound proofing.

Can't say what oil is in the car right now, bought it 3000km ago and the oil was like new when I got it so I haven't done an oil change yet.

I'll try all of these things tomorrow on my lift, see if it only does the sound when the car is in gear or not.

Okay so, my technician and me checked the source of the noise and it seems to be comming from the front cover. Top right side of the car.

Any idea what could cause that issue?

:confused:

If he checked the source, why can't he tell you what it is?

He thinks it's the VVEL cam but he's not 100% sure.

I'm asking for your opinions

Again, make sure you got the right oil. If it’s coming from the VVEL, you need to start with an oil change to a good synthetic or Nissan Ester oil. Then you can go from there. The VVEL system is a very unique design that is known to make weird clicking and rattling noises especially when the oil is incorrect.

It could be the VTC which is the Varaiable Timing Chain cam gear. If that is what it is, check you oil pressure with a gauge. You may have a Galley gasket that has blown out causing low oil pressure to the VTC.

How big of a job would you say the oil gallery is on the Z? Should I change the timing chain stuff while i'm there?

What oil would you recommend?

If that is what it is. It is a big job. The front cover has to come off to get to the galley gaskets. If you are high miles then yes I would suggest you change the timing chains, tensioners, water pump, and timing chain guides.

Its only at 68k miles, not exactly high miles but not low either

Galley Gaskets have went out at that low a mileage before on the 2011 and earlier. I would change it all.