Ok, so I changed the oil in my jeep 2 days ago... no idea what the po had in it or how long it was in.. I put regular 10w30 In and now it ticks on start up and the oil pressure gauge pegs at 80 when cold and pretty much doesn't drop driving or idle. It used to be a out 80 cold 40 at idle and around 50 driving around. Should I try some 5w30 synthetic? Its a 96 4.0 with 109k miles.

 

What brand of oil filter did you use? Did you by chance bump the oil sender when changing the filter? Those readings are very high and indicate a faulty sender.

 

Purolator filter. I dunno? I may have bumped it, the old filter was on tight so it got stabbed with a screwdriver.

 

I'm putting my money on a bad oil pressure sending unit.

 

I think its time for a mechanical gauge then! I still think the oil is a bit thick, it has been really cold here, and that 10w30 non synthetic probably turns to syrup when the temp drops below 0.

I think I'll drain it out and replace with some synthetic 5w30, and get a mechanical gauge. Considering how much this thing was obviously neglected by the previous owner(s) it still runs and shifts really nice

 

I think you're wasting money changing from 10-30 to 5-30. Verify your oil pessure with a rented/loaned gauge first.

 

My reason for changing is it didnt tick before on cold starts, but now it does with the new oil.

 

I had this same problem a few months ago. I always use Valvoline MaxLife and that is what I bought. Instead of 5w20, I used 10w30. Damn thing started ticking... so being a worry wart that I am, I went and got some 5w20 and changed it again. It still ticked until I put on about 10 miles. It isn't anything to worry about my man.

 

That old 4.0 don't know the difference between 5w and 10w. I would change just the filter and use a Wix or Napa Gold. Note how much oil comes out when the filter is removed. Does it dump all over or have just a trickle? I'm not convinced that Purolator is that great of a filter.