xht5889

ok, so heres my problem, figured id get some advice from veteran 350Z owners. i have a 2006 touring with 110k. six months after i bought it, i noticed when its super cold out, normally 40 degrees and below, if i drive it without warming up i get a loud whine seemingly coming from under or behind the car, gets louder as i go faster, but goes away once it warms up. Also sometimes shifting from 4th to 5th i sometimes get a grind. Now im having more issues. The clutch engages with the pedal almost all the way up, not sure if this is normal for a Z but the other manual cars ive owned engaged halfway thru. The car has lost some acceleration power and now when shifting into any gear after 2nd, it seems the gear slips before engaging. The RPM needle jumps about 500RPMS before starting to move the car forward. Also, if going over 30 and i try to accelerate, not even a powerful push but say just enough to overpass someone, it seems the transmission slips before starting to move faster, sometimes the rev meter jumps 500-1000 rpms before engaging. However, heres the catch, it only does this for 2-3 days and then goes back to driving normal. HEELLLLLP!! does this sound like a clutch issue, or is it time for a new transmission, already changed the gear fluid in transmission, no fix.

jerryd87

iTrader: (4)

its impossible for a manual transmission to slip all the gears are connected to each other it dosnt use friction like a auto. its likely clutch slip, the whine sounds like a wheel bearing or rear diff.

TheWoo

iTrader: (2)

+1 on the clutch slipping, as it seems to be wearing out on your car. You'll find the clutch progressively having a harder time holding power, until even 2nd gear will start slipping under aggressive acceleration. I suggest getting a new clutch and new flywheel, or resurface your flywheel somewhere that can resurface a dual-mass flywheel (try a shop that specializes in BMWs). An uncommonly high engagement point for the clutch pedal is normal for a stock 350z, but a worn clutch disk will make the clutch engage even higher. While you have the transmission out, replace the pilot bushing and the throwout bearing, too.

As to that whine, jerryd87 is accurate in his suggestion that it's either a wheel bearing or the rear differential. Jack up the car, place your hands at 12:00 and 6:00 on each wheel and wiggle the wheel using a rocking motion to check for any bearing play. Keep in mind that any play in the front wheels can also be caused by worn-out control arm bushings. If the whining comes from the rear differential, a differential fluid change could fix it, or you can just swap out the entire pumpkin with one from a low mileage 350z, or better yet, from a '08+ G35/G37/370z with the 3.692 final drive (you will gain a small increase in acceleration with a correspondingly small decrease in top speed).

Honestly, the only major thing you need done is the new clutch and replace wheel bearings if they are faulty. The 5th gear grind can be mitigated by rev-matching your shift more accurately. Rear diff fluid change is pretty easy.

All the above tasks have guides in the forums in case you want to tackle these jobs yourself.

04.350z

iTrader: (5)

If its a factory clutch its time for a new one. I toasted mine by 60k but like most owners i drove that car into the ground. As far as the grinding i believe there was a tsb for the syncros in the year you have. I had the same issue on my 04 and replaced the sycros and it fixed the problem and if you are baby kind of lowered you may need wheel bearings ... Hard to tell without diagnosing in person and none of here fixed are cheap unless you have the ability to do it your self

Quamen

iTrader: (14)

Low trans fluid may also cause whine.

04.350z

iTrader: (5)

This is true

bjr

Do investigate the whine for other causes but be aware that separate from your possible tranny issue, there is a well documented whine in the drivetrain below 40 degrees. Several threads on this site regarding it. And it will go away after a few minutes depending on how cold it is. Mine has done it throughout the car's whole life and now has 188,000 miles on it. No problems.
Much debate on it but I believe it is in the tranny even though it seems to sound from the rear end. To me the proof was that even though I put a completely different and completely rebuilt rear end in my car to add LSD the noise is still there, sounding exactly the way it always has, pointing to it not being the rear.
Good luck!