The 2001 XJ is a brand new vehicle to me, ran fine while test driving. Oil was very dark and appeared to need changed badly but I saw no sign of milkshake. Coolant looked a bit old too out nothing out of normal really. I heard some engine ticking but pretty much have heard that from nearly every older wrngler or cherokee (of acquaintances)I've ever heard so did not concern me much.
Then I drove it longer...oil pressure dropped to the point of popping on check gauges light at stop light. So I drain and change oil and filter...still no sign I could see of water/coolant, it just was dark dark.
Changed plugs, they looked used but not bad to me.
Read about the 0331 block plague of 2000/2001 and pull valve cover. Cleaned off area between cylinders 3 and 4 real well and saw nothing
https://www.dropbox.com/sc/uplopvpoc8kbttp/kqVaZJ6kJ8
Made cardboard oil damn to see if I was getting oil. Things were real gunky/sticky and black. Perhaps ran too thick of oil or additives or perhaps bars leak or something?
https://www.dropbox.com/sc/qcsl6ae7n63by7v/vAinhoqJbq
Rockers and pivots did not look like they should for an engine with 93k miles on it. Intake rocker (closest to firewall) rocker on cylinder four could be wiggled by hand making clatter. I fed the lifter some mmo, cleaned things up a bit and put cover back on.
https://www.dropbox.com/sc/u9l0yl13jvgwnmq/ExV9fpjx-t
Since then I've flushed the coolant and added fresh to get a better baseline. I've felt as if the oil level has risen...and the coolant has gone down...but just a bit. I guess I need to drive more miles to really know but then was hoping to put as few on it as possible prior to alleviating the problem.
In the end this will be a vehicle that only get about 6k miles per year put on it, mostly 15 minute to 30 minute jaunts with a dozen 45 minute jaunts pulling a 2000lb boat/trailer pre year. So, while I know the new head will likely not cure the low oil pressure problem, I may decide to let it ride a bit since under most of the oil, which seems to come to temp about 20 minutes after the coolant, will just be getting up to emp on most trips.
At any rate... so I figured I'm just about to rip the head off and if I go to the trouble of disconnecting the exhaust headers, I may as well find a good junk yard head for $200 and put it on. Should kill the issue of having scraped up rocker/pivots as well.