[Angst]

I replaced the heater matrix this week in my 2002 R50. Symptoms were :-

• coolant loss (slow but consistent),
• poor heating (would kind of feel warm if the fan was low but on higher speed felt cool)
• very damp on the inside of the windows (especially cold mornings which is why I just did it!)
• musty smell

When I removed the old matrix, there appeared to be slight perforation around the 'shoulder' at the end where the pipes are attached. Noticeably warmer in the car now it's been replaced and the system filled and bled.

The heater matrix is right behind that plastic panel so if it's getting warm you should be able to feel it without removing the panel.
I've left the panel off mine for the time-being just to make sure there are no leaks before I put the panel back and the matrix gets too hot to touch (as you'd imagine).

I have read somewhere that in some cases, on removal, the matrix appeared OK but is clogged up so a flush was all that was required.

 

[Angst]

Also, make sure you are filling the system via the theremostat neck and are bleeding from both bleed screws - the one on the top hose and the one behind the thermostat that goes through the bulkhead to the heater matrix. Sorry if this is obvious