tazman wrigglesworth

2000 Sport - 4.o L., 4X4, Auto.

Read a lot of posts on this subject and still have questions. I have the same problem as many others - low/fluctuating oil pressure. I flushed motor with 10-30, put Seafoam in with fresh Castrol HM 10-30 and Fram filter. Engine was quiet, but gauge was still pegged at 80 psi. Changed out the old OPS and pressure now read 0 at idle and @ 30 under load. Proceeded to change oil again, Castrol HM 10-30 with MOPAR filter and put in Mechanical guage to replace OPS. Result was the same readings.

My question is this - I have read in other forums people with the same problems, esp. the 2000-01 and they have replaced the oil pump, sending units, etc. with the end result being no change. Should I start eliminating by price - check pump next, then bearings, head, etc. or should I be looking to rebuild or buy new engine? This is my DD and I need solid advice for the fix. What order should I be looking to fix and what head would be better than the dreaded 0331?

Sorry for the long windedness - just a bit frustrated and out of ideas.

captainwoot

I think your best bet is to rebuild, low or no oil pressure is the result of excessive brg clearance canshaft/crankshaft brgs. So to change the oilpump, or oil grades is just prolonging the inevitable......
Good luck!

98 JeepJeep

not always true........

you have to remeber that the oil pump is the ONLY thing is the system that gets the un filteres oil......so they CAN wear and cause a low pressure issue.

To the OP at this point i would drop the pan and replace the RMS install a new Melling Standard Volume pump and put on a new OP gasket and give it a try.....

tazman wrigglesworth

That's probably what I'll do, however while the pan is down, I'll look at the rods and mains to see how they look. If they look worn, I'll be looking at a total or partial rebuild. What are the things I need to change to let this thing live for another 10 years? Do I have to look at a total rebuild or could I just replace the bearings, pump, head ('02 or newer 0331) for prevention sake? What should I be concerned with if it's not the pump and to what extent should I rebuild? Any advice is appreciated.

98 JeepJeep

in order to do it right if you are going to replace the bearings the crank should be removed and cut .10 also.....advance auto sells re-man engines for a goood price and they have a 3 year warranty.......

tazman wrigglesworth

Thanx to all who replied. After researching for days, I came to the conclusion that buying a reman 4.0 from Advance was the way to go. Having someone to rebuild would have cost more with a very limited warrenty. Too bad my oil problems came up. It was one of the strongest running 4.0 I've driven. Beats the hell out of my son's '99 GC with 1/2 the miles of mine.

98 JeepJeep

Good Choice.......

jgeorge

I have a 2000 jeep cherokee and the oil pressure gauge jumps all around. It usuall stays in the middle, but when turning and driving it moves all over. Is this bad.

jeepmonkee

I have a 2000 that had low oil pressure 10-20 at idle.At 100k I decided to switch to 10w40 and never looked back .30k miles later still have 25-30 at idle even after long trips.I'd give it a try before spending serious money on an engine, without engine noise or issues.