View single post by Mark Rosenbaum
 Posted: 07-27-2005 09:58 pm
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Mark Rosenbaum



Joined: 03-12-2005
Location: Kingman, Arizona USA
Posts: 532
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 My car's PO changed timing belt and tensioner bearings just before I bought the car.  Nonetheless, the engine frequently made whining noises. Some folks kept telling me, "It's a Lotus engine, it's supposed to whine," while others were certain that the whine was quite abnormal.  At that time, I did not find either explanation convincing.

Eventually, through a process of elimination, experimentation, and research, I satisfied myself that the cause of the whine was an over-tight timing belt.  Rather nervously, and expecting a catastrophe at any time, I reduced belt tension in small steps until the whine occurred only occasionally.  At that time I could twist the middle of the exhaust-cam-to-crank span by about 45^.

I drove the car that way for about a year.  By the end of that year, the car was reliable enough to take long drives, and I had become completely fed up with the whine.  I reduced the belt tension in steps until the noise went away entirely.  At that time I could twist the belt by a bit more than 90^.  I tightened the belt slightly until I could turn it just barely 90^.

That was about three years ago.  On rare occasions the engine makes what I can best describe as a faint predecessor-of-a-whine, but nothing more.  I don't take the engine above 6000 rpm very often, but it gets up to 5500 all the time and I have yet to see any problems with the timing belt. 

I've had people with access to a Burroughs belt tension gauge tell me that the one does, usually, get the correct tension when one can twist the belt 45^ to 90^ as described above.  Of course this would depend on the strength of an individual's hands and is very non-scientific.  But it seems to work okay for me.  YMMV, of course.