I have finally located my coolant leak.At first I suspected the auxillary coolant pump, but it is now clear that the leak is a pin hole in the radiator , on the right edge of the rad , half way up.I ( or down ! ) . I have no garage space so the car is destined to be outside over winter. I plan to replace the rad in Spring when it warms up, and in the meantime I will try to stop the leak with a coolant additive. Any ideas on the best one to use.
Anything you put in the radiator now will be nothing but headaches later.
I used to be a fan of Barrs Leaks. But my current project car (that crap got past a bad head gasket and glued the pistons to the cylinder walls!)
If you can access the area of the hole, drain the coolant below the area and run in a self tapping screw coated with gasket shellac into the hole. Let stand 5 hours before refilling. That’s a solid 1 year repair.
I have replaced a few S-Type radiators in the 2003 to 2005 range and they ALWAYS leak from the right side tank area. The X350 uses the same radiator.
I see that Nissans makes a radiator with the auto trans oil cooler so that might be an option to the dealer supplied part. I used to buy the OEM from the dealer a few years ago because it was the cheapest ‘proper’ radiator with the trans cooler fitted.
People were talking about using the inexpensive ones and putting a separate oil cooler for the gearbox.
Rock Auto sells the Nissans 66708 but there might be other sellers local to you.