Nissan Repair: 1990 nessian speedometer, vehicle speed sensor, three thousand miles

Question
i have had a stroke so forgive spelling. i have a 1990 240 sx the speedometer is broke  is this a electronic and what is a good price to replace it also some white smoke  when i step on gas while neutral  what is that mean

Answer
Lowell,

The speedometer is probably the vehicle speed sensor on the transmission.  The smoke could be valve seals due to the year.  Try using Penzoil 5W30 oil and a pint of restore in place of a pint of oil when you do the oil change.  It should correct the problem for three thousand miles until you need to change the oil again.  If not, have the system checked to see if the car is bleeding exhaust into the coolant passages; as in a bad head gasket or even a plugged converter that is causing excessive back pressure...