help with oil pump

[mike4089]

can anyone meet up with me sometime this week and help me install a new oil pump in my 83 cj-7....it has the 258 in it, and when ever the motor warms up the oi pressure drops really low....i wanna change the oil pump and hope that is the casue of the problem....i dont know to much about jeeps so someones help would be highly appreciated.........

[Big Pimpin]

That is not out of the norm for a 258, as long as it has some oil pressure and goes up a little with RPM you should be fine.  I wouldnt think that changing the oil pump is going to make a difference but it is worth a shot.

[LibertyPatriot]

I ran a mechanical gauge on two different 258 in the same CJ5 and they were almost identical in oil pressure.  The second engine was a little better.  Fire up cold and have around 35-40psi, then at full engine temp it would idle around 7-10psi.  From everything I've read, that's normal.  You can install a high pressure pump, but if the engine has some wear to it, you could spin a bearing in the lower end and really mess things up.

As long as the pressure doesn't drop so low that you hear way too much clatter of the rockers, you should be alright.

[Overland n' Rocks]

a high pressure/volume pump will also put most of the oil in the top of the engine instead of the pan, which will cause lots of gaskets to leak (e.g. valve cover, manifold, etc.)
high pressure pumps were intended to used w/ reduction buttons on the crank & rods.
If the thing has pressure at all & doesn't KNOCK or Rattle, I wouldn't touch it.

[mike4089]

well at idle....i some times have to look closely at the guage to make sure the needle is off the pin...then while driving its only at about 10 psi....at idle it does have some vavle chatter.......maybe i will hold off on it i guess....i just dont want to screw anything up and have it cost me to fix it....what type of oil should i be using viscosity wise........?

[LibertyPatriot]

I ran 20/50 when it was warm.  I had to change my gauge out to one that had larger graduations so I could see the difference better.  The one I have is a cheapo from Pep Boys, but it has several marks between 0 and 10.