> Rear heater fills car with sweet, anitfreeze smell when turned on.
> I cannot see any leaking fluid however and don't want to change the core
> just for the heck of it.  Is the core expensive?  Best source?

First of all, make sure it's the core that's leaking (most likely) and not
the valve (less likely but still possible), which is a different part.
Usually you can go a little while with a bad core, and just shut off the
valve, but if the leak becomes severe it can cause problems.  In my case,
the leak did become severe but it was leaking below the core and seeping
through a body seam, so I didn't even know that it was leaking until I lost
a lot of coolant. The coolant traveled through the undercarraige of the van
and was dripping out of a drain hole near the propane tank when I finally
noticed it. I have a friend with a '90 carat that had a similar experience,
and he overheated his engine as a result.  So be cautious, or bypass the
core.  Better yet replace it.

By the way one of my suppliers is running an "off season" special on these
cores, since there is minimal demand for heater cores in August.  The price
is $79.95, for an original-equipment core.  This is a very good deal, but
will probably only last a couple of weeks.

- Ron Salmon
 The Bus Depot
 http://www.busdepot.com