That "Click" maybe a control switch (safety) shutting it down. I doubt you
can hear the expansion valve and they never become intermittent.
If the system was not properly evacuated before being charged  moisture
inside can collect and ice crystals can form and block the outlet of the
expansion valve quickly creating very high head pressure. There may be a
freeze switch also on the evaporator.

Dennis

-----Original Message-----
From: Vanagon Mailing List [mailto:vanagon@gerry.vanagon.com] On Behalf Of
John Rodgers
Sent: Friday, July 01, 2011 11:15 PM
To: vanagon@GERRY.VANAGON.COM
Subject: Frydaye Follies - BMW question

  My buddy here has a 1990 325i BMW with an A/C problem. When the system is
charged and turned on, it runs for 4 or 5 minutes and can be felt blowing
cold air. Then there is a loud click-click up under the dash and the air
stops being cooled. I suspect this is the expansion valve acting up, but
don't know for sure. I have been told that is where the valve is located,
and if so - it appears to be a beast to get at - like the heater motor on
the Vanagon - the dash has to come out.

Can anyone confirm this? or tell me what they think of the situation and
what steps he might take to remedy the problem?

Thanks,

John

--
John Rodgers
Clayartist and Moldmaker
88'GL VW Bus Driver
Chelsea, AL
Http://www.moldhaus.com