Rest easy Volswagener...

sounds like one or more of your lifters drained or "got sticky" while your
van was sitting. 

If you want to be super anal-retentive and careful:
 remove the valve covers, disconnect the coil wire and GROUND IT. Using a
ring wrench on the main crankshaft pulley and peeking at your distributor for
guidence, roll the motor to TDC #1 and check the valve clearance, Clairance. 
Roll the motor to TDC on 4, 3, and 2, checking the clearance on each.. If one
of your lifters is sleeping, one or more of the measurements will be slack.
Then you will replace your valve cover gaskets, they could probably use it.
Put everything back together and start the van, allowing it to idle a while,
then driving it gently. The ticking should go away as the lifter fills or
loosens up.

If Sans Souci is you motto:
strart the van and drive it. If the sound doesn;t go away in the first couple
miles, turn toward your mechanic.

Also: see the archive about sticky lfters and the "Motor Flush"/Double
oilchange solution.  Best of luck!

GMB, Fairfax, VA
Lookin' a '87-'90 Westy
1985 Jetta Turbo Diesel
1976 Transporter (AGAIN?!!)
ex 1976 Transporter
ex 1972 914 2.0
ex 1973 Squareback
ex 1985 GTi
ex 1970 914 1.7
(family) ex 1972 Transporter
(family) ex 1962 Microbus
(family) ex 1958 Karmann Ghia