T25 DG & Similar - Oil Priming
Posted: 09 Apr 2012, 16:40
Surprised little mention of this on forum. When I recently rebuilt engine, despite greasing the oil pump spur gears, could not get any oil pressure when cranking prior to start-up. Incidentally, never ever after any engine rebuild connect the ignition until you know that oil pressure is OK by just cranking - if the engine starts & runs and there's no oil pressure, you'll have wasted a shedload of time and money. VW Heritage (their Nigel Howe is incredibly knowledgable and I would recommend purchasing from them if only to be able to ask this guru questions) was aware of this occasional problem and suggested loosening oil filter whilst cranking. This didn't actually work and I was starting to panic about whether I'd rebuilt the oil pump properly! So removed filter completely and with a squeezy tubed bottle injected oil into the hole in the housing which effectively back fills the pump. Then cranked again with the filter refitted loosely and sigh of relief - oil dripping down the loose filter = oil pressure!