From digest.v7.n480 Thu Oct 23 13:11:37 1997
From: bmrfamly_at_nwlink.com (Dan, Marilyn, Phil Patzer)
Date: Thu, 23 Oct 1997 06:00:33 -0800
Subject: (M30) Maintainance Free Chain
Your 535i should have a cam chain which is capable of incredible longevity.
They do stretch, and the crank and cam sprockets do wear. Each time the
valve cover is off for checking the banjo & head bolts/adjusting the
valves, you can check the chain for looseness with a coat-hangar.
Turn the engine by the crank, or the nut on the front of the alternator,
just enough to start to move the cam. Now all the looseness is on the
passenger side which is where the tension shoe is located. This shoe can
only move so far, then any additional looseness is just slop and it can
endanger the well-being of the engine as they can hop the teeth of the
sprockets, sending the valves into the pistons.
If you can wiggle the chain and it's other than "stiff" movement, it's
time to change the chain.
These usually out-last the condition of the valves and it's quite easy
to change the chain while the head is off for a valve job.
My wife's chain lasted 350k miles and could have made it more but I was
there so I did the right thing.
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