It just started this week, My YJ with the 4.2L and FI has started to drop to zero oil pressure at idle! But it doesnt do it every time but it does it very often.

Could this be a problem with the oil filter or is it much worse. (I fear much worse :( )


Oh, and it used to drop to zero every once and a while when at a funny angle on the trail as well but I would always give the engine a little gas and the pressure would come right back up.

bro no oil means no blood which also means no life for engine. Yank the pan check the oil pump, the oil pressure sending unit, and the filter. If its none of those its worse. I wouldn't start the engine anymore though thats like saying your going to run up a hill but you can't breathe:eek: have fun hopefully you'll explore her in ways you've never imagined possible

Before you get your panties in an uproar, get a mechiancal gauge and check the pressure.
electric gauges sometimes read 0 and could be a sender or a wiring problem.
Oh, and a stupid quetion, but is ther oil in the engine? If so, how low is it?

Hey, mine does the same damn thing. Not at first, but more ofter the longer the engine has been on... Mine say ZERO, and I dont think the engine would run too well with no oil pressure. I have to get a mechanical gauge... but Others have had this problem. Tell us what you find out.

It's a very common thing. The 258 only builds up a head of steam when it needs it at higher rpm. When at idle it creates hardly any pressure (around 8psi?). Even after a fresh and complete rebuild mine's always done it. Have had a lot of passengers fret about it when we're idling along and they see the needle hard left :D I've had this particular 258 since '94 and it hasn't blown up yet ;)

As above, I'd check it with a mech guage to verify. Your sender is probably on it's way out and just not registering the small amount of pressure that is there.

Rob:smokin: