Changed filter housing gasket...now low oil pressure!? HELP

[Nick_S]

So as the title states. My oil filter housing had been leaking like crazy. Replaced the gasket, the o-ring and the oil pressure sensor. As well as some other stuff (rethread valve cover bolts, intake manifold gasket, spark plugs, thermostat). Anyways, got it all back together today and it fires right up but the oil pressure light is on and the valves are ticking bad, like a real cold temp start bad. I had used that Next-gen recycled oil 10w-40. It ran for a few and the light went away but still was ticking a bit. Shut it off, checked the oil level and it was fine, no horrible leaks from anywhere. Start it up again and drive it around the block, it had been sitting for 3 weeks so was hoping maybe it just needed the oil circulated around. Still ticking and if I sit idle for too long the oil dummy light comes on. Drove it home.

Swapped out the oil pressure sensor for the old one figuring maybe it was just faulty unit? restarted and sounded quieter with no oil light. Drove it around the block. Ticking comes back. Parked it in the garage and figured maybe that next-gen oil is just shit. So I went and picked up Castrol GTX 20w-50. The M50 in my wagon is real sensitive to oil and will tick a bit with the wrong oil. Changed the oil again. Start it up. Oil pressure light stays on for a bit longer than a normal oil change and went away. Was quieter but still ticking (not the normal M42 tick). Now I'm at a dead end where I've tried all the basic things that I know of to check and hence why I'm asking here. What possibly could be causing my low oil pressure and valve tick? Changing the gasket was pretty straight forward so I'm not sure if I could botched that up? Any help is appreciated. Also should note, the car had none of these characteristics before I replaced anything leading me to believe I have re-installed something wrong.
Thanks
Nick

Pics of the motor. Just got done cleaning and repainting everything.

[Nick_S]

Couldn't imagine it would make a difference but I also remove the A/C which wasn't hooked up anyways and the powersteering.

[Nick_S]

Well this was no help.

Quite certain I found the problem anyways. Damn gasket shifted letting air into the system which is probably why my oil pressure was low.

[TobyB]

D'oh.

When I changed that gasket, it took FOREVER to get it to build oil pressure
(cranking with the plugs out) and pushed a bunch of air around.
I had the head off, so the lifters leaked down and were noisy at first, so I didn't
think much of it at the time.

I wonder if yours pumped air into the lifters? That would make 'em noisy....
they take forever to really quiet down after that, but they do eventually.

fwiw,

t

[decay]

appropos of nothing ITT, but i like the paintwork, very nicely done from what i can see.

[Nick_S]

D'oh.

When I changed that gasket, it took FOREVER to get it to build oil pressure
(cranking with the plugs out) and pushed a bunch of air around.
I had the head off, so the lifters leaked down and were noisy at first, so I didn't
think much of it at the time.

I wonder if yours pumped air into the lifters? That would make 'em noisy....
they take forever to really quiet down after that, but they do eventually.

fwiw,

t

It ended up being the slipped gasket. Pulled it resealed, reinstalled. Good to go!

appropos of nothing ITT, but i like the paintwork, very nicely done from what i can see.

Thanks, always like a clean looking engine. Was planning on making a thread once I'm done with my "spring improvements".