I swapped a 1998 D16Y5 into my 1995 civic VX. The engine came from a car I had that was totaled-out (rear ended). The engine had less than 40000 miles on it and ran fine before the crash. It sat in my shed for 6 years or so. Before I swapped it out I pulled the head to inspect it. All looked fine. I had a valve job done while it was off. The timing belt and water pump was also changed. I got it running last weekend. It sounded fine. I let it run for 30 to 45 minutes. Other than the ruff idle, do to the IACV being for an automatic instead of a manual there was a very slight oil leak. The leak appeared to be from the corner of the head in the front of the car on the tranny end. Today I pulled the intake to convert it to a manual IACV. I had to remove the oil filter to get at a nut. This is where the question starts. The filter had NO OIL in it. What could be wrong? Would the engine run 30 minute without oil? Thanks Bert