Oil not making it to the filter after timing job and oil pump upgrade

[eddytheexpy]

Hey all,

I just finished up the good ol 5.4l 3v timing job with HV melling oil pump upgrade. I went to prime it by turning the key with the crank sensor pulled and had no oil pressure. I thought it was just taking a little longer than normal and gave it a few more tries with ~10 second bursts. Nothing. I was beginning to think I may have screwed up the wire harness to the oil pressure sensor but did a dummy check before chasing a bad wire. I removed the new oil filter that I just put on and it was dry aside from the oil I put on the gasket.

I have no idea what to do now. Anyone have suggestions?

I also pulled the oil pan at the end of the job and checked the pick up tube for debris (it was clean) and re checked the torque of the bolts on the pickup tube to oil pump flange while I had a better angle with the pan removed. and yes, I put 7 quarts of oil it and put the new gasket on that came with the oil pump.

 

[eddytheexpy]

just had a thought and figured if there's air in the pump, it can compress unlike oil. so it can just compress the air an not actually pump oil. I looked into it and that seems like I'm onto something. I'm going to do the procedure linked below tomorrow.

Melling Tutorial for Priming your Ford Modular Oil Pump !

Melling tech director Cale shows how to prime the oil pump on your Ford Modular engines!If you have technical questions, please call 800-777-8172 or fill out...

www.youtube.com

 

[eddytheexpy]

well, it worked! So the above video is a great supplement to FTM's 4 part series. Plus, it's an instructional coming from the manufacturer and not at all hard to do so you should probably do this anyway.

 

[JamaicaJoe]

I wonder how long these engines can sit before the prime is lost on the pump? It could be a concern.

 

[eddytheexpy]

after getting oil pressure and processing the relief of finishing the timing job, I was wondering the same thing! But I feel like oil could pool in the lower section of the pump and not actually lose ALL of the oil in there. Once it starts to move that’ll probably help create a seal allowing the suction to start.

I think in my case with it being as dry as it was, it’s not so much that it was compressing the air but more so that the air is super viscous in comparison to oil. So it could sneak out between surfaces way faster than oil can which is where the lack of suction came from. Once it has a good coat of oil, I doubt it’ll run dry enough for that to happen again. But, during my research of the issue, I found out that you should prime the engine if it’s been sitting for an extended period of time.