Hey Ron,

Let's start with the malfunctioning O ring theory.
If the O rings are malfunctioning can you get the light
coolant smell lets say if the small amount of coolant
is dripping on the hot in and out pipes.

I've pulled both sides of the carpet to gain access
to the heater matrix. Did about a dozen times now
so i'm comfortable with it and quick.
Have not removed the matrix
cover yet. From what your saying there is nothing
to tighten at the in and out pipes to secure them
to the core. Does the core just sit on the O rings?

I remember someone here saying to jiggle the core
back and forth to get it off the pipes.

I did a seach and found little info on the core
exchange procedures.

Yes, your right, the heater core problem on the 70
series seems to be a growing malady. Volvo must of
made a poor supplier decision.

ty

rd