Oil pressure issue on the RB25

[Zedman240®]

Just wondering how much oil pressure should there be under crank? Removed the oil pressure sender tonight and turned the engine over and nothing comes out. I remember with the L series at least you would see the oil pressure gauge move before the engine started while cranking. Thought the sender was failed, fitted a new one with no results. Sender wont work if there is no oil to pressurize it! Filled the sump with oil, pre-filled the oil filter before installation like I always do but nothing! Did a quick bit of research and apparently early RB25's had a oil pump drive issue. Hope this one doesn't or else some conversion parts will be on the market and the original L24 will be back in the engine bay!

[Enzo]

G'day, Try priming the oil pump with STP oil additive. The stickiness creates suction. I had a new L26 motor about 4 years ago that would not show oil pressure when cranking over on the battery, so I hooked up the electrics and fired it up. The oil pressure came straight up. This was safe because the bearings all had been lubed with STP on the rebuild. Regards David.

[Zedman240®]

Problem solved! Just needed some compressed air through the rocker cover breathers and the oil filter removed while cranking the engine and 5 seconds later, presto! oil pumping out of the centre of the oil filter mount. Re-fitted the filter, cranked the engine some more and oil pressure started to register. I guess after sitting in the wreckers yard for so long the oil disappeared from the pump and these pumps aren't self priming! Thanks for the suggestion anyways..