Engine knocking sound on Ford Fiesta LX 1.25 Zetec (1997)

Hi,

I have a Ford Fiesta LX 1.25 Zetec (1997 / P-reg in UK) which is in excellent condition except for what I can only describe as a light metallic 'knocking' sound coming from the engine.

A couple of people who have more mechanical knowledge than myself (but not professionals) have suggested it could be any of the following:-

Cam belt / cam followers / oil pump / big end bearings / camshaft

Before I take it to a professional mechanic if absolutely necessary, I was wondering if any forum members would have any further advice on what could be the cause. I understand this is probably impossible to diagnose from my vague description, but any advice on where to focus my attention would be greatfully recieved!

I will try to get some more accurate info on the noise tommorrow, but in the mean time here is what I know so far:-

* Engine rattles / knocks at tick over and at higher RPMs.
* Noise is more pronounced when going up hill.
* Noise appears to some from right hand side of engine (looking at it from the front of the car) but it's hard to tell.
* Oil light on the dashboard does not seem to come on at all (not sure if this is related but I'm sure it used to come on with the ignition and then go off after a few seconds).

If anyone thinks it would be of any use, I could probably record an audio clip of the engine noise and post it here for you to listen to.

Any help would be much appreciated!

Thanks