under 15psi at idle and i would be worried.

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Have you ever noticed that anybody driving slower than you is an idiot, and anyone going faster than you is a maniac?

As long as they would add one additional commandment for you to keep thy religion to thyself.
George Carlin (Wonder where he is now..)

1981 240d (engine donor 1983 240d) recently rebuilt engine hurray! - No more.. fought a tree and the tree won.

pearl black 1983 240d 4speed (Converted!@$$%) atleast the tranny was rebuilt.

At hot idle, the usual MB specified lower acceptable limit is 0.3 bar, or 5 psi.

As long as the pressure builds rapidly as soon as the engine speed increases, it'll be OK for years, as it's oil flow, not oil pressure that holds rubbing parts apart.

Edit: Forgot to say that another possibility is the oil pressure relief valve sticking slightly open, allowing oil an easy route to go back to the sump.

The only thing not to do is to become tempted to use thicker oil - stick to the hot viscosity recomended in your car's manual. Typically, this is 40.

I also had extremely low pressure during idle while hot. I fixed this by replacing all the rod and main bearings. It was a true reading. After the rebuild, oil pressure at hot was back up again.

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Michael LaFleur

'05 E320 CDI - 86,000 miles
'86 300SDL - 360,000 miles
'85 300SD - 150,000 miles (sold)
'89 190D - 120,000 miles (sold)
'85 300SD - 317,000 miles (sold)
'98 ML320 - 270,000 miles (sold)
'75 300D - 170,000 miles (sold)
'83 Harley Davidson FLTC (Broken again) :-(
'61 Plymouth Valiant - 60k mikes
2004 Papillon (Oliver)
2005 Tzitzu (Griffon)
2009 Welsh Corgi (Buba)