Heater Core Replacement (Range Rover 4.0/4.6/P48)

Wet Carpet Symptoms and Diagnosis
When the front carpets in your 4.0/4.6/P38 Range Rover suddenly gets wet, it can be due to several causes. It does not necessarily mean the heater matrix has failed (as was notoriously the case on the Classic)! Much more likely, it is simply a matter of either blocked air conditioning drains or that the heater O-rings need replacing. So check these out first, using the following diagnosis procdure:

Heater Core Replacement on LHD Range Rovers
Thomas Dirksen (who pioneered the abbreviated procedure described in the O-Ring replacement page) also had occasion to change the entire heater core. Officially, replacing the heater core requires the removal of the entire dash/fascia. However Thomas found a shortcut method that makes this operation much more bearable. "After removing the glovebox, I drilled through various spot welds on the dashboard frame. Then I partially sawcut an "ell" bracket (that helps support the dash) and gently bent it out of the way to remove the heater core. I then lapped to pieces of metal and riveted the frame back together, and then riveted the spot welds I previously drilled. So it is possible to change a p38 heater core without removing the dash fascia."

In September 2008, Chuck Brazeau went through the above diagnostic sequence and arrived at the inevitable conclusion (heater core failure) after owning his 2002 Range Rover only 2 weeks. Chuck read about Thomas Dirksen's procedure and decided to try it and fill in the detailos for us. He has kindly contributed the following complete description of the shortcut procedure he followed to replace his heater core.

Dismantling the Passenger (Right) Side Dash

The photo below shows how far the passenger side interior needs to be disassembled. First, the glovebox is removed. The subsequent procedure includes cutting the rear passenger side duct in half and removing the lower half to access the heater core connections, as well as removing the passenger kick panel. Notice the plastic on the side of the center console has been cut out to give access to the upper duct screw and the heater core connection screw (with a long screw driver or extension). The cutout was done with a dremel tool, and a small file was used to smooth it out.

Cutting and notching the Dash Support Bracket
One cut and a small notch needs to be made on a metal bracket under the dashboard so that the bottom of the dashboard can be bent out of the way slightly to slide the heater core out of its compartment.

Unbolting the Lower Dash Mounts and Extracting the Heater Core
Three bolts at the bottom of the dashboard mounts need to be removed in the passenger footwell. (see photo below).

The bottom of the dash can now be pulled out just enough to slide the heater core out of it's compartment after the pipes have been disconnected and the lower distribution servo has been removed (two small screws).

Reassembly
Once the new heater core has been installed, the bracket that was cut is now braced with some aluminum flat stock and self tapping screws.

The remainder of the dash and glovebox reassembly is straight forward, following the reverse order of disassembly. Chuck was very happy that this repair could be done in just a few hours time using these shortcuts.

RHD Models
Chuck is not sure if the above method would be of any help to RHD Range Rover owners.