hoping somebody can help.

Just had timing chain guides replaced in TN astron 2, now sounds like police car, mechanic friend says it will wear in. Is he right????

Not sure as mine never made a whining noise when I replaced it.

I've never heard of a high pitched whining following chain replacement

mine does it intermittently at certain revs, not too loud though.

Are you sure it's just not the standard whine from the astron motor, and you can now actually hear it with no rattle rattle noises drowning it out :P.