E30 More Continuing Heater Woes

["Jason E. Markel" <markel@xxxxxxxx>]

Like many others before me, I am experiencing a major heating loss so far
this winter.  My drive to and from work is getting a tad intolerable once
the temperature dips below 20 degrees.  I pulled apart a good portion of
the dash this weekend, but failed to determine the real problem.  Here is
what I know so far:  

1.  at full heat I barely get enough warmth to defrost the windows after 10
minutes of running the engine.  The center vents won't blow hot air no
matter what.

2.  the outside of the heater core gets damn hot, as do the aluminum pipes
going in and out.  So, I don't think the problem is related to the blend
valve or core itself.

3.  the tension in the temperature dial isn't normal.  It gets tight as I
approach the end of the red zone but still turns the whole way.

4.  at full operating temperature I stuck my hand in the lower (floor
directed) heater ducts.  When I turn the temp dial I can feel the blending
flap move.  At full hot I feel some hot air, but can still feel cold air
blowing in.  A push on the flap reduces the cold somewhat, but it won't
maintain the position.  The cable cannot be adjusted further and, in any
event, the flap won't close any more than it does via the lever attached to
the cable.

So, my only guess at this point is something must be jamming the blend flap
or something is broken in there.  Any thoughts?

How do I access the blend flap to check?  Do I need to remove the heater
core?  Can I take the blending assembly out to check it without disturbing
the A/C?  Does the Bentley manual provide a detailed schematic? (head
hanging low in shame...I only have the Chilton and the big BMW repair
binders, both of which are woefully inadequate for this task).  I stopped
short of touching this stuff because I have no idea what I'm getting myself
into.

Your thoughts are greatly appreciated.  Buffalo winters can be long and
cold without a heater.

Jason
87 325

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