2000 xj8l 4.0 v8

Heating . . . get “some” heat once engine is warm / thermostat (X2)?? It’s cold in Michigan lol

Get an OBD11 reader and see what the actual temperature is, it might be thermostats or if its like an XJ8 it might have an auxiliary heater pump?

Hello Sdmarm - since you are not getting full heat inside, check to see if your coolant level is full - sounds like you may have some air in the heater core instead of it being full of coolant, which is the usual reason for not enough heat inside - Tex Terry, II - 1991 XJS V12 Classic Coupe, 1986 XJS V12 Coupe - sent 12/1/2020 1044hrs. EST USA.

Terry, if the system is like the XJ8 then there is an auxiliary water pump and a valve that oscillates to regulate the water flow through the matrix so a few things in the mix that can go TU. I had to replace both the AUX pump and the valve on my ‘99 XJR recently.

Hello Robin - what you state makes sense that there may not be enough hot coolant present - Tex Terry, II - 1991 XJS V12 Classic Coupe, 1986 XJS V12 Coupe - sent 12/01/2020 2051hrs. EST USA.