[Healeys] Loud Metallic Click

[Skip Saunders]

Patrick,

Richard's ideas are good....but here is another one:

The cam is held in place by a plate that attaches to the front of the
engine.  This plate is constantly undergoing wear by end of the rotating
cam.   On every engine I've ever taken apart, the plate is probably the most
worn part of the engine assembly.   Regardless of oil quality, there is
nothing that will stop the effective drilling motion of the cam from
eventually wearing pretty severely into that plate.   Hence the plate needs
to be replaced whenever an engine is rebuilt.   

If that plate is allowed to wear enough, the cam will drift forward inside
the engine and eventually reach a point where the cam lobes do not perfectly
line up with the cam followers.   The number 4 cylinder cam follower closest
to the front of the engine will be the first one which starts to click
because it is the one with the least tolerance margin.   If you put a
stethoscope tip on the cover plate which covers the number 4 cylinder cam
rod followers, you might hear the metallic click a bit louder than the
others....but if you have this problem, the clicking will be pretty loud
throughout the engine.

The solution is to remove the chain cover, take off the cam keeper plate,
and look at the side of the plate experiencing cam rub (drilling).   You'll
see a pretty deep groove if this is indeed the problem.  Simply replacing
the plate will fix the problem.  (In a pinch, you could just flip the plate,
but I wouldn't drive like that for very long because the drilling action
will continue on the new side until you have a hole completely drilled
through the plate.)

Hope this helps
-skip-


-----Original Message-----
From: healeys-bounces at autox.team.net [mailto:healeys-bounces at autox.team.net]
On Behalf Of Richard Ewald
Sent: Sunday, April 24, 2011 12:07 AM
To: Patrick and Caroline Quinn
Cc: <healeys at autox.team.net>
Subject: Re: [Healeys] Loud Metallic Click

Listen to the noise, and you might be able to narrow it down a bit.
If the noise is constant at 1/2 engine speed, think rod bearings, they only
knock on the firing stroke If the noise is constant at engine speed think
piston problem, bent rod, or the dented oil pan that mentioned.
If the noise comes and goes at 1/2 engine speed look for a dropped valve
seat.
If the noise is random (not at engine speed or 1/2 engine speed look for a
pulley or whatever.
If the noise is at 1/2 engine speed try pulling spark plug wires one by one,
if the noise gets quieter it is a rod bearing for that cylinder.
Good luck and I hope that whatever it is, isn't too expensive.
Rick
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