Wife's friend says her engine is sounding "like a sewing machine" so I offer to listen. Lots of valve train noise. Check oil - no oil on dipstick! Added 1.5 qts 10W-30 and brought it up to nearly the full mark, noise considerably quieted. Questions (I'm a Volvo guy and know nothing about Toyotas): is this '93 Camry 2.2L 16V engine one of the "sludge monsters" I've heard about? The fill cap certainly had a lot of coked on residue inside of it. What is the oil capacity? The filter (she has a Napa 1394 on there) is the smallest I've ever seen! Any oversize filter options? Car has 144K - I'd say Auto RX treatment for sure, anyone disagree? Lastly, engine compartment sticker says timing belt was changed at 67K in 1999, 77K and 5 years ago. She's on borrowed time there, isn't she?