Rattle that starts at 3000rpm - suspect low oil having caused hydraulic tappet damage and subsequent rattle noise (see 'Noisy Hydraulic tappets' above) try some RESTORE and make sure to keep the oil level at...
One cylinder ticks when cold. Check for a cracked exhaust manifold that closes up when hot, before looking at piston slap, noisy tappets, block charcoal canister, small end bushing and big end knock etc.
Noisy Hydraulic Tappets can be cured by simply pouring RESTORE into the normal engine oil. If you have an older style (ie pre-hydraulic lifters) worn valve guides and cam bushings we recommend removing the...