Re: [alfa] Buzz in 1750 at ~ 2300 rpm

[Mark Battley <M.Battley@xxxxxxxxxx>]

-------------------------
The 1750 in my Giulia Super has developed a buzz/vibration right about
2200-2300 rpm.  It goes away above or below that rpm.  It seems to be
internal
to the engine, not in the externals, sheetmetal, or the like.  Is that the
rpm
that loose timing chains resonate at? 
-------------------------
Yes, or there abouts..
-------------------------
I checked the top chain recently and it
seemed tight.  By the "pry with big screwdriver" method I couldn't get it
any
tighter than it was. 
-------------------------
I've been through that a couple of times with worn chains that appeared
tight, but would still rattle. Spent ages retightening them by various means
including the big screwdriver, eventually replaced the chain, let the
tensioner spring do the job, and it was quiet again.

I'm still puzzled why they can seem tight but rattle, unless some parts of
the chain wore more than other and happened to be over the sprockets, or
maybe a worn chain has enough extra degrees of freedom that it moves around
more, dunno?

Mark Battley
Auckland, New Zealand

1973 Alfa Romeo 2000 GT Veloce
1989 Fiat Uno Turbo
1999 Fiat Marea Wagon, 2.0 20V
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