Followed the 'nipple bleed' method today for my Pathfinder.
Rigged up a pipe from the bleed nipple to the expansion bottle and started her up.
Put a block on the pedal to allow around 2000 rpm. slowly got hot.
The diesel's rad fan runs all the time on a clutch so is always cooling.
Left all the heater fans off until the temp gauge moved a bit, all seemed warmer.
Off again until running temp ( about 30 mins at standstill )
Loadsa bubbles in the pipe.
Put all back to normal and went for a ride and the heater seems loads hotter.
The temp gauge still drops to about quarter when truck left ticking over.
One thing I've noticed is the bottom rad hose stays cold. Google searches some say that's normal others point towards thermostat ??
Doesn't look to bad a job to get to ?? Then another bleed after.
Id 'tip' the car so engine block thermostat hole facing up so not to loose to much antifreeze?? and clamp the top hose.. Good idea?
Here's my spammy quick Youtube video
https://youtu.be/IMxVKSiJ2Jk
The extra tube was in an antifreeze bottle to syphon some of the fluid safely out as it warmed up and the expansion bottle filled up. Only once did i need to do this.