vtraudt

200k on the motor. Running well. Experiencing low oil pressure at idle.
New pick up tube and oil pump.

I want to rebuild (and upgrade) the engine (new main bearings, piston rings, valve springs, solid exhaust valves).

What is the most likely cause for the low oil pressure, and what can I measure/check to determine what needs replacing?

Can the HEADS be worn and cause the low oil pressure (and rendering the heads not suitable for rebuild?).

x19

Do your engine have 2 oil pressure switches (Dynamic oil pressure system) ? If so, one of switch has weaken and replacement need. x19

vtraudt

I used manual gauge to check oil pressure, to avoid relying on the 1 factor plus 1 add on (interior gauge); but hte OEM "switch" as well as the extra (separate adapter ring on oil cooler) interior gauge match the precision gauge values.

So I DO have low oil pressure at idle.

Prospeeder

Yes cam bearings can wear out and render the head junk causing low oil pressure. Its the first thing Audi says to check before removing the oil pan when experiencing low oil pressure. Although they say engine replacement if its been oil starved enough to have cam bearing issues.

vtraudt

What are the specs for the cam bearings to determine wear out?
Procedure/how to measure?