strange ball valve in my engine

[isuzu]

Hi, recently I cleaned up my oil pressue valve and wondered what that thing was just above the valve.
When I remove it out comes a ball and spring. The ball is half exposed to the " open air ". Just as if it is closing off an oilway to the outside.
Can't see this thing in my manual and wonder if someone knows what it is?

[a10 gf]

1st thought, once upon a time someone had an oil pressure gauge fitted ?

[muskrat]

I would agree and when the tube was taken out a ball was inserted to seal it.

[Rgs-Bill]

I would agree and when the tube was taken out a ball was inserted to seal it.

  Why would a fella use a ball and spring when taking off the oil pressure gauge, when the chance of a ball and spring failing and pumping the oil to the outside world, plus not having oil pressure to the white metal bush, would be kinda engine failure scary. I would source a blanking brass fitting with no hole in it instead.  Just a crazy thought. Comments welcomed of course because I am probably all wet. What say you Musky ????  I wonder what else might not have been done properly on this machine, KINDA SORTA sounds like more Investigation is required. ????

      BILL

[bsa-bill]

another possability
it's a device to assist priming the oil galleries?
seems a bit OTT but who knows
If it were the remains of a pressure gauge circuit why the spring, the ball would seal if correct size but a plug would be so much better as BILL suggests, and someone with the skills to fit a pressure gauge would surely consider this before a spring and ball

[Derby Rob]

is it some kind of self sealing fitting for when you fit/remove oil gauge ?...just a thought

[muskrat]

Looking again it is positioned to pick up the blow off side of the oprv  . May have been fitted to check the oprv was blowing off. That sounds naughty.
If I were you isuzu, I'd replace it with a 1/8" BSP plug, preferably brass tapered, as BILL suggested.
Cheers
 

[isuzu]

Thanks for the comments guys. Think the oil pressure gauge must have failed in the past and this was an easy way to close it. Do not understand why they put in the spring behind the ball as it has no function at all. The ball is just forced into the pipe opening and cannot move at all.
Ill find me a blanking plug .....
Gr Dick