123psi is optimum? For what?

My near 300000 mile M103 still was in the 160-170psi range.

Try a new tester. Are you sure you are operating it correctly... plugs out, throttle fully open, etc

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I'm not a doctor, but I'll have a look.

'85 300SD 245k
'87 300SDL 251k
'90 300SEL 326k

Six others from BMW, GM, and Ford.

Liberty will not descend to a people; a people must raise themselves to liberty.[/IMG]

Yes I'm sure; I did it how they taught me at school.

AllData stated in the specifications section (for my engine) that the normal compression is 8.5 bar (@~14.5 psi/bar = ~123 psi). Perhaps I miscalculated the conversion from 8.5 bar to psi...

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Simon Shearer

1986 420SEL

2000 Porsche 911 Millenium Edition Carrera 4
2010 Lexus RX 350
2002 Kia Rio
2002 Hyundai Accent