Nissan Skyline R31 Auto overdrive problem

Question

Hi,

I have an '87 Nissan Skyline R31 automatic. I have a problem with the overdrive not engaging until the engine gets right up to temperature (just over 1/2 way on the gauge) - which is usually at least 15km from a cold start. From everyone I have spoken to, the overdrive should engage only after a few km. Unfortunately in the morning I drive 20 km on the freeway, so fuel consumption is terrible (80km/h @ 3000rpm - I can hear the fuel tank gurgle at that rate). I have had the gearbox serviced recently but that didn't fix the problem with the overdrive (though the gearbox changes very smoothly now!).

Does anyone have any ideas what the problem could be? I don't want to spend heaps of $$$ at the mechanics/auto electricians chasing down dead ends trying to diagnose the problem so any suggestions would be gratefully received!!

Answer 1

If your flooring it its going to engage, Try easing the throttle

BTW nice  skyline i like them boxier lol    i have a 2001

Answer 2

Physically if the transmission is in good shape then I would look at the temp sensor inside the transmission oil pan. Anything you did to improve the cooling of the gear box? I get this condition every year or so the customer insists that the gear box worked fine before changing the fluid. In the Nissan Service manual there is specification for the ohms reading for the temp sensor. Basically you can install a small resistor into the temp signal circuit to alter the voltage running back to the Transmission control module. That way you will get overdrive before the trans actually  is at 80c temp

Answer 3

common fault of this on autobox is an solenoid in the box

Other thought is when i had my R32 Auto Skyline it wouldn't also allow power to the car reached a set temp a new Temp gauge was needed to help this problem.