More fumes

[jadney@vwtype3.org (Melissa & Jim)]

>From: A bear in his natural habitat <burden@rhett.ENET.dec.com>

>How would the fumes get from the back of the car all the way up the back 
seat?  
>Why only when the windows are open?  I periodically check the exhaust 
>connections for leaks (black soot), but even with leaks (if there are some) 
how 
>are the fumes getting in the car?

The usual port of entry is along with heated air.  Does the problem go away 
if you shut off the heat (valves on the heat exchangers must work.)  Small 
leaks at the connections between the lower heat exchangers and the muffler 
can blow forward and under the heat exchanger shroud where it mixes with 
fresh air and is blown into the passenger compartment.

Bernoulli's principle causes the moving air across a window to pull a small 
vacuum on the interior.  This will help the heater (opening a vent window is 
really effective) and also make things worse if you have a leak elsewhere.

I have been toying with getting a set of two-bolt flanges to go on that 
connection instead of the usual vw compression seal that I don't have a lot 
of luck with.  Has anyone else done this?

Jim
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       Melissa Kepner                                    Jim Adney
       jadney@vwtype3.org              jadney@vwtype3.org
                             Laura Kepner-Adney
                             Madison, Wisconsin
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