The pinking suggestion seems to make sense, though it doesn't seem to fit the "quiter when warm" observation.

The terms in this area tend to be misused, but I think "pinking" is usually taken to mean "knocking" or "detonation"

I dunno much about recent cars, but wouldn't something this new have a knock sensor, so it'd alter the ignition timing to stop it happening?

In my 1986 Skywing I've had an intermittent sharp tap that I suspected was pre-ignition (not exactly the same thing, but a knock sensor probably couldn't tell the difference) but it was less regular than the OP describes. (my sound card is stuffed so I can't listen to the vid.)

It went away after messing around with water injection into the running engine, tending to confirm the diagnosis.

You could try that (its free and shouldn't do any harm with distilled water in a plant sprayer, though that'll take a tediously long time) and/or try upping the octane rating of your fuel and seeing if it makes any difference.

Edited by edlithgow on 17/04/2014 at 15:32

it sounds like tappets after listening on decent headphones,ps if this has the same tappets of the earlier model the tappets wear around valve stem so using a feeler guage is useless

Also had oil feed problems that I recall

I may be wrong but it sounds like it

This would make sense..

I'll try to get some pressure testing equipment to check it. But the sensor is not showing any problems, so I doubt this would be the problem.

For now, I'll just see whether I can check the pressure through the OBD port.

As to the past of the car - I have no idea. But it had only one owner, it was a lady in her 70s, then it was not used for about 3 years. The dealer changed the oil, oil filter and sold it to me. But the car doesn't have full history, there are a few service (MOT) checks, but nothing else.

What do you think of this:

https://www.youtube.com/watch?v=5pEXfYd3wIM&feature=youtu.be

This is the noise when stationary.

When analysing it, I've slowed it down to 0.1x, and I could hear the individual cylinders firing - you can clearly hear that one of them is a lot louder than all the others.

https://www.youtube.com/watch?v=AIg6Iu1eFKs&feature=youtu.be

What do you think?

As to knocking:

Say that that was the case, wouldn't the big clearance on the valves make them open later and close earlier than needed - thus worsening the whole timing ?

What should you typically do in these situations? Adjust the tappets to make the clearance within the limits, or would it be fine for a little over the limit ?

I've no idea whether they're the same. All I know is that the 1.25l engine has hydraulic, 'self adjusting' tappets, and my 1.4 has the mechanical ones that need manual adjustment through replacement.

Do you think it's worth spending a few £ on the new shims? There's 8 of them for the inlet, so it'll be a costly thing to replace..

Edited by Chris Abr on 17/04/2014 at 20:53