u/Funnyjohnlucas5420

I have a 2008 Saab 9-3 2.0 BioPower that suddenly started making a ticking/knocking noise. It almost sounds a bit "diesel-like". You can hear it at idle too (video attached).

I checked the oil right away and it was fairly low, so I topped it up. Not completely sure when the oil was changed last, but I think it was sometime early last year. Running GM Dexos 5W-30.

I changed the spark plugs a couple of months ago, cause it was having trouble starting, and the old plugs were pretty sooty. Not sure if that’s related.

Could this be lifter tick / low oil pressure? Is it worth trying an engine flush + oil change first, or does it sound like something more serious?