VTC failure is very common on the 1992-1993 Maximas SE (VE30DE engine). It causes the engine to make a clattering sound that goes away after the engine warms up. Repair involves rebuilding the VTC assembly or replacing the assembly.
Prices vary greatly depending on the shop, but you can get a good idea of what a "reasonable" price is from parts and labor charges.
Spring assembly ~$25.66 x2
Gasket ~$11.25 x2
Labor: 5.7 hours @ ~$65/hour
(Note: The above data was taken from an invoice for a VTC rebuild performed in May 1997)
VTC Sprockets ~$292.99 x2
Plus misc. parts
Labor: 6+ hours
For a rebuild I have been quoted from $400 at a local shop to $1200 at a Nissan dealer. For a replacement I have been quoted up to $2400 at a Nissan dealer.
Supposedly the new VTC assemblies are improved and will not fail, but several people have experienced VTC failure again 20-30k miles after having the assemblies rebuilt.
There are two technical service bulletins that deal with VTC failure:
NTB95-022 deals with VTC failure, and the rebuild/replacement process.
NTB93-189 deals with top end noise in VE30DE engines. It lists VTC failure as the most probable cause of this noise.
The VTC system is controlled by two solenoids (one on each cylinder bank). Some people have claimed that you can diagnose VTC failure by unplugging the wire from each solenoid. If the noise level increases, your VTCs are working, if it stays the same then they have failed. I tried this on my 1992 SE and noticed no change in noise level.
This page is being developed as we learn more about VTC failure. As such, not all of this information is completely verified, and in no way is this page a complete discussion of the problem.