Two problems related to noises during shifting have been reported for the 2003 Nissan 350Z. The most recently reported issues are listed below. Please also check out the statistics and reliability analysis of the 2003 Nissan 350Z based on all problems reported for the 2003 350Z.
Bought a 2003 Nissan 350z used from keyes Nissan of woodland hills,CA. Tiptronic (auto/semi-manual) transmission needed to be replaced within 45 days. Now a whining noise that is still not fixed as well as excessive heat from shifter area that causes passengers to sweat & scalding hot to touch. Car hasn't seemed to run right since. Seems every 350z owner has the same atypical problems-tire feathering, transmissions replaced,rear axles, power window motors fail(the last 2 are my next trip to the dealer). Nissan needs to fix our nightmare. Nissan support is nonexistent as well,which makes your ordeal all the more miserable.
There is a hesitation when shifting into third gear, and when it goes into gear, there is a grinding noise. Dealership replaced the manual transmission, but the problem recurred 5000 miles later,and needed to be replaced again.