Hi there

The engine has a rebuilt head, new chain and guides. It's running a light-grade engine oil. Oil pressure drops to 0 when idling warm. If I rev it goes back up to 3. 120,000 on the engine.

Should I be concerned? Main bearings?

Thanks!

How light grade? You don't give your location, so I'm not sure what climate you're in, but you should probably be running 15w40 or 5w40. You also might want to verify that your gauge is working properly.

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Whoever said there's nothing more expensive than a cheap Mercedes never had a cheap Jaguar.

83 300D Turbo with manual conversion, early W126 vented front rotors and H4 headlights 401,xxx miles
08 Suzuki GSX-R600 M4 Slip-on 26,xxx miles
88 Jaguar XJS V12 94,xxx miles. Work in progress.
99 Mazda Miata 183,xxx miles.

Im in the North-East. New York. The car is not on the road at the moment. I just run it to get the valves seated. I forget which oil exactly -- the guy who did the valves suggested a very light oil. 10-50? Is that possible?