Don’t they have Explorers in Boston? This is a common problem with the Idle Air Control valve. Cleaning the valve has some success, but most have to replace the valve for about $70. As far as the hose falling off, there is a possibility at this age of a rubber cap falling off on the vacuum tree or the hose to the vacuum modulator on the transmission. If any hoses on the tree are oily, the modulator is leaking.
Don’t they have Explorers in Boston?
I would not want to drive one in Boston.Back with slightly modified name after about a years absence when they changed the board. Never could get signed in with the old name although it is listed in the mid twenties of people without a life.
This sounds like the “moosing” problem. The “moosing” sound has often been said to sound like a fog horn rather than a french horn. This issue has been discussed in the Ford Explorer forum:
http://www.explorerforum.com/forums/showthread.php?t=136952
My 1995 Ford Contour also had this problem which turned out to be a design problem. The fix was to install a redesigned idle air hose. The new hose has a resonator attached:
http://www.woodfam.com/ryan/svt/moose_fix.html
-R.
While I didn’t hear the very start of the call, I did hear ‘French horn’ and cold start.
I’ve had a similar problem which I traced to the thermostat. As it began to open, an oscillation occurred that made quite a loud sound just like the one the caller described.
Hope this helps, although the earlier response re: Idle Air Control Valve seems to be a known problem for this (Explorer) vehicle.
Al76