Searching the forum I can't find any posts describing this condition. '96 FZJ80, 1FZ-FE, 210,000 miles. This is a recent development. On cold start (temps around 40F) I'm registering nearly zero movement on the oil pressure gauge. After warmup (coolant at full operating temp) oil pressure registers just below the first mark. Goes up and down with revs, but not above first mark, and not as much as was normal in the past. In summary: Gauge shows no pressure on cold start, but shows some (low) pressure after warmup. Basically backwards from what is normal, and lower than normal. No oil consumption No coolant consumption No mechanical noises No power loss No unusual temperatures Recent work: Head gasket 15k miles ago. Good compression. Front seal and oil pump cover seal 4K miles ago (I.e., crank bolt) Blue fan clutch and mod 4K miles ago Oil change 1,200 miles ago with small Napa (Wix) filter (only thing available at the time) To do: 1) check crank pulley bolt for proper torque. (I did the crank seal 4,000 miles ago) 2) measure pressure wth a mechanical gauge 3) oil overpressure bypass? 4) defective filter? Anyone seen this condition before? I'm open to any advice.