NG engine making a knocking noise when cold and ocassionally when hot.

[Robert Stirrat]

Hello,
         This is a question for the oily-handed amongst you.   My 92 Series
III Coupe has started to make a knocking noise from the engine, about five
or six knocks can be heard when I start it from cold.  When I run rev the
engine by pulling the throttle cable, one or two knocks can be heard.  It
sounds to me that the noise is coming from the top end at cylinder 5.  There
is no loss of power or oil pressure from the block.

I took it to a local garage, they had a look at it and seem to think it
coming from the bottom end, and said they'd need the car for two days to
drop the sump and check the shells.  Is this likely to be the crankshaft
bearing shells or the connecting rod shells?

Is there anything else it is likely to be?

I should mention that I also had a ticking sound from the lifters, this
prompted me to check the oil level.  Curiously, this was below min, curious
because I had the oil changed some 6K miles ago, and also curious because I
don't have any leaks.  I topped up the engine with .75 litres and the
ticking has gone.  You may also recall I had a misfire on cylinder 1
recently which I sorted with a replacement lead.

I'm telling you this as I am wondering any of this symptoms were
contributary to the onset of my engine noise?

Will the connecting rod and crankshaft bearing shells be replaced as a
matter of course along with the sump gasket when the garage carries out this
work?  Is there anything else I should insist upon them replacing when the
have the bottom end apart?

All help is appreciated, I like to go armed with as much knowledge as I can
when dealing with mechanics.

Thanks again,
                     Robert.