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Subject:Of gas mileage and coolant temps...
From:Alan Bosch
Date:Thu, 18 Jan 2001 08:35:51 -0600

Okay...  If this has been discussed here before, slap me and I'll go back
to my little corner of the net and try to find all I can about bar-b-q and
a great rib recipe...

General question for the enlightened on the list...  Is there a correlation
between gas mileage, the exhaust system, and the cooling system on our
Van's?

For the last few months I've been trying to get to the bottom of why my Van
seems to run hotter than it did when I first bought it.  After poking and
prodding, I can find no leaks within the cooling system loop.  No head
leaks, no hose leaks, no heater leaks, no cracked expansion tanks or
reservoir - nothing.  A leak-down test proved nothing.  The mechanic that
did the test indicated that the system held pressure for "...quite a
while...", twice.  I have redone the coolant system bleed three times since
July, and each time the temp still indicates hotter than normal.  (For
clarification, I consider "normal" to be indicated by the temp gauge needle
resting anywhere on the LED.)  These days - indeed, for the last six months
- my temp needle is resting just off the LED, on the high/hot side of the
gauge.

Okay, perhaps that's just the way the van is supposed to run.  But I got
thinking - dangerous! - on the ride into work this morning.  Since all my
exhaust connections, from the j-pipe back thru the muffler, all seem to be
leaking - indeed, the muffler doesn't anymore - maybe the O2 sensor is
getting a faulty reading, causing the engine to run richer, making it run
hotter, and decreasing the MPG.  The inter-connectedness of all things...?

Grasping at straws?  Or is the logic sound.

Opinions, education, and enlightenment welcomed and appreciated.

Alan Bosch
& Phred ('88 Wolfsburg)