Weird noise coming from engine continued

[AudiJeep@aol.com]

I must have bumped some key and accidentally sent my mail before I finished
writing it. Sorry about that. My '92 100S has recently had some major engine
work done to it, including replacement of the timing belt and head gaskets.
Ever since I've had this work done, the engine makes a weird noise on cold
startups. This whining noise sounds similar to the sound a manual
transmission makes while in reverse. The noise usually lasts for about a
minute of so, and will go away if you rev the engine a couple of times. Has
anyone else had this problem? Could the timing belt have installed wrong?
Could the water pump be the problem? Thanks for any input.

Craig
'92 100S (63k)