dougskiing

I'm looking at a 2000 Jeep sport classic ( 4.0 inline six ) with 135k miles on it. ( to purchase ) When idleing, the oil pressure is low , about 10-12 psi. There is also a "ticking sound" at idle too. When driving, the oil presure is at 35-40ish. I was told by the seller that they recently installed a new oil pump. Any thoughts on these issues, causes ... would be appreciated.Thanks, Doug

itsanxjthing

Well... is it low on oil? Last oil change was when?

mr.auto

my jeep runs anywhere from 60 to 80 psi. im guessing if everything looks good maybe he didnt install it right and or didnt prime the pump either

00xj-classic

13 psi on a warm idle is NORMAL.. The haynes manual states that.. also 37-50 or so above 1600 rpms is NORMAL.. BUT the 00 and some 01 xj's have the 0331 cylinder head that can crack if overheated.. this will cause low oil pressure at idle and from what i have witnessed a little increase in temp.. Check for white sludge on the oil cap, good indication the head is cracked..

kriebz

My '01 is doing this, too, to the point of frequent "check gauges" light showing. Happened after my first oil change after I bought it from a dealer, right around 90k. Maybe he was running heavy oil to hide it, I don't know. It idles smoothly, but won't stay put, going between 500 and 600 RPM randomly.

I hear that tap if I listen really closely, and it worries me. I've done plugs and coil pack already, which might have been causing a mis-fire (unrelated? who knows). I've also done frequent oil changes trying to find an oil/filter combo that works better. It drinks a little water, and the coolant has gunk in it from that evil orange stuff they used to use, which I'm trying to flush out. I'm also ran STP through it and that didn't help either. Maybe replace the crank and/or cam position sensors soon unless I get more evidence it's a head or head gasket problem.

Other than that, it runs great really. I'm getting OK but not great mileage, maybe 15 mixed, not quite 20 highway.