Hello, I seem to have come across a knock but it is a weird one and cant figure it out. Coming from drivers side of the engine and it isnt constant, happens on and off for 2 seconds each time roughly. Took the valve cover off and it all moves freely. Just happened one day after sitting for a week.

Any info much obliged

TIA

Did it just happen one day, or has is continued since it happened one day? If it is an ongoing issue I would invest $10 in a mechanics stethoscope to help pinpoint where the noise is coming from. Did you check engine oil level?

Don't say model/year/mileage, but the old 2.8/3.1'* were known for "piston slap", where the engine would have a knocking/ticking noise on a cold start, and then would diminish go away as th engine warmed up.......however, if this went on for year, the noise would not go away....

You can short out each cylinder, to try and isolate the cylinder noise....