A mate of mine has gone thru every varible they could think of spending way over 1000 bucks with no diagnosis in the end was a simple tune that rectified problem consisting of timing and fuel adjustments...
I must admit all varibles he did purchase and go thru, all did help out a bit in the end it was like ABRAKADABRA timing and fuel FIX'D !!!
I thought my TD4.2T was getting to hot it turned out to be the crappy/faulty factory Nissan gauge. It's probably the problem with most the 4.2'S that people think are getting to hot buy a aftermarket gauge and be done if your worried
i would like some measurements from you guys who dont have heating issues
the measurment i am after is from where the flange of the thermostat sits, down to the hole that the bypass valve of the thermostat would block when the thermostat opens
on mine it is 40mm and if i had a factory thermostat fitted then it would have to open up 9mm before blocking the bypass hole, if you guys that dont have heating issues have a measurement less than 40mm (say 34mm) that will explain why some run hotter than others