Rattle at 2500rpm

[COSMO]

Strange thing lately but it seems there is a rattle between 2500-3000 rpm's and it seems to be coming from the engine. Whats funny is it seems other have had what seems to be the same noise from what I have researched. The noise does not occur under decal or anything over 3000rpm's and there is no power loss. I just had a new clutch and flywheel installed and just hoping maybe its just something with that. Any ideas or thoughts? Oh I do also have the gtm stage II twin turbo kit as well for those who didn't know...

[/Angelo350Z/]

Originally Posted by cosmogirl

Strange thing lately but it seems there is a rattle between 2500-3000 rpm's and it seems to be coming from the engine. Whats funny is it seems other have had what seems to be the same noise from what I have researched. The noise does not occur under decal or anything over 3000rpm's and there is no power loss. I just had a new clutch and flywheel installed and just hoping maybe its just something with that. Any ideas or thoughts? Oh I do also have the gtm stage II twin turbo kit as well for those who didn't know...

Did you have it before the flywheel was installed? Lightened flywheels tend to make that rattling noise.

[Chuck33079]

Flywheel would be my guess. Mine rattles quite a bit.

[COSMO]

Iam almost certain it was going on before the new clutch/flywheel install... Not to mention at start up there is no noise.. No oil consumption.... Dammit where's spohn when you need him..

[RZ14]

Been having the same problem with mine for about four months. Nissan has replaced everything in the power train except the transmission....which they ordered yesterday. They reported that only one case from their "tech line" had the similar issue and was repaired once the transmission was replaced. Good luck.

[COSMO]

Well I cant say I would be surprised since I had to replace my tranny on my 350z... The thing is the noise seems to be coming from the timing chain area on the very front of the motor.. I guess only time will tell..

[/Angelo350Z/]

Hmmm ... if it's coming from the front of the motor, and you've had it even before you replaced your flywheel, it could be the harmonic balancer (vibration damper), or something simple like an engine mount.

[sstroudwku]

To only appear in that RPM range it could be a harmonic issue. It could also be in one of the VVEL assemblies. That's when they start to stage into the higher lift. If you don't have a DMF "dual mass flywheel" the transmission will rattle something fierce. I've had to explain this to many people. Our manual transmission does not have end play tolerance specifications. So the gears, syncros, bearings, everything on the main and secondary shafts shift and move.

[Chuck33079]

Originally Posted by sstroudwku

To only appear in that RPM range it could be a harmonic issue. It could also be in one of the VVEL assemblies. That's when they start to stage into the higher lift. If you don't have a DMF "dual mass flywheel" the transmission will rattle something fierce. I've had to explain this to many people. Our manual transmission does not have end play tolerance specifications. So the gears, syncros, bearings, everything on the main and secondary shafts shift and move.

I've got the same noise, and it only showed up after swapping to a lightweight one piece flywheel. I'd say you hit the nail on the head.

[Nut_N_Much]

I have notices a rattle on mine, when I got out and looked at the front of the engine it looks like my belt tensioner is moving and the sound is reverberating through the engine mounts to the cab. The movement matched the sound.

I forgot to remove the pin that was holding the tensioner, after I installed the SC I put the belt back on and I had the noise. Something else to check

[roplusbee]

I would say working as intended, but I am sure no one wants to hear that. There is a point as someone mentioned where there is a transition in the valvetrain. I don't have the rattle, but I have a noticeable stumble or hesitation right around 3k. I spoke about reporting back once I found the issue and/or solution, but I have not found anything but more questions.

The one thing I can say for certain is it happens mostly when you are light (very light) on the throttle. If you would dare to do so, use varying techniques to rev thru that range and then revisit the though.

[Cell]

Originally Posted by roplusbee

I would say working as intended, but I am sure no one wants to hear that. There is a point as someone mentioned where there is a transition in the valvetrain. I don't have the rattle, but I have a noticeable stumble or hesitation right around 3k. I spoke about reporting back once I found the issue and/or solution, but I have not found anything but more questions.

The one thing I can say for certain is it happens mostly when you are light (very light) on the throttle. If you would dare to do so, use varying techniques to rev thru that range and then revisit the though.

I hope it isn't a problem and working as intended or else anyone that replaces there flywheel for a lighter one will face issues...

[COSMO]

The thing is it was doing it Before the clutch/flywheel....

[regulator11]

Mine does the same thing. But the noise will go away after the car has been running for about 10 minutes. If i idle for a couple of minutes and start back up again the noise returns and then goes away after more driving. I have a single turbo and stock clutch that is starting to slip so i will be replacing to a light weight flywheel soon.

[phunk]

the noise you are describing is from the transmission. It is there stock, but no where near as loud as once you replace the stock flywheel.

it can be very loud at times, and is generally loud at idle, and louder when loading the trans/engine below 3000rpm. it is usually much quieter while the trans fluid is still cold. idling on a hot day in a drive through, the noise is loud as hell and the drivethru window person will think your car is totally busted.

its completely typical of this transmission and does not mean any failure is impending. 350z's did it also (same trans, different case), and go on doing it for years and years and years with no issues. My 350z trans was extremely loud and lasted like that for 9 years before my friend who bought it finally had to replace the gearset due to the 3rd gear break that eventually happens at high power. Even with the brand new gearset in there that he took out of a HR trans and put in his DE trans case, it still makes the noise.

When sitting at idle next to a wall at full temp, when its being LOUD as hell, you can confirm it is the transmission by simply pressing in the clutch, and noting how the sound completely goes away. Unfortunately those of us with twin or triple clutches, get to exchange that sound for the loud chatter of a multidisk clutch any time the peddle is down.

No worries!