'89 BMW 535i question

[Mayooran Pooranachandran <mayooran@xxxxxxxxx>]

Hi All

Have a question for you all regarding an '89 BMW 535i automatic.
Something that my BMW mechanic cannot seem to
solve.

1 month ago, my mechanic redid the head, including head gasket, new
camshaft and rockers.  Since then, when stopped at lights or even in
park, the idle
would dip below 500rmp and picks up and stabilize at norm for 2-3
seconds.  Most times it would stall.  My mechanic has replaced the
airflow meter (?) and it still did not help.  2 days ago, he replaced
the Motronic(?) computer.  The problem seem to still exists except it
does not stall.  When braking to a halt (heavy/normal braking), the idle

would drop below 500rpm and bounce back to norm once the car is
completely halted.  While halted, (in drive and park), there is a
rhythmic
vibration of the whole car (like the idle dropping), but the rev meter
does not show any drops.  When in neutral, there seem to be no signs of
any vibration but the sound of the exhaust and the sounds of the engine
do seem to indicate idle drops but rythmic (normal idle...slight
drop...normal idle...slight drop...). Any ideas?

Also, what do you think of the garret chips?  The same mechanic
installed it into my '90 325i.

All your help and/or suggestion(s) wil be greatly appreciated as my wife

will be using this 535i next year.

Mayooran Pooranachandran
mayooran@domain.elided

'89 535i  (Stock [I think...]).
'90 325i (Garret Chip).


PS: I am in Toronto Canada.

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