740 blowing freezing air!

It's cold here and my non-air conditioned 1989 740 is taking a long time to
start delivering warm air and doesn't really get hot inside the car at all.

The worst part is that it's blowing out very cold air from the vents down by
my feet almost all the time, regardless of the blower settings. This is not
a good thing!

The engine temperature is normal, i.e. in the middle of the range after a
mile or two.

Any ideas what to investigate?

 

just a guess, but.... on my '89 240, there's a vacuum line from the top of
the engine back into the dashboard. I had some problems with the rubber
splitting, until I finally covered the last inch or so of the rubber tube
with silicone sealant, which has kept it intact for the last 2 or 3 years. I
think that line operates the flaps in the heating system that direct air
over the heating and cooling cores. Without vacuum, I'd suppose they default
to a "cold" setting, so you might want to check the vacuum lines and see if
any are split or disconnected....

m9876c at yahoo dot com

 

If the engine temp is normal it means that the heater valve is not
operating properly. If it is vacuum operated then check it with a
vacuum gauge connected to the line, and/or by applying vacuum to the
valve and seeing if it operates. It is is a mechanical valve,
disconnect the cable and operate it manually. In either case, hot
water is not entering the heater core. Less likely is a clog of some
sort in the core or related system somewhere.


__ __
Randy & \ \/ /alerie's
\__/olvos
'90 245 Estate - '93 965 Estate
"Shelby" & "Kate"