AFMan

When you replace your stock oil pump with a hi flow P4529241, do you have to pound out more room in the Oil pan? And do you have to replace the oil pan gasket, or can you use your existing one?

RoyalXJ

yes you have to clearance the pan and should replace the gasket. you should do a rms when your down there

5150mechanic

Isn't odd how 9 times outta 10 its a 2000 or 2001xj? These engines have cam bearing issues despite the 0331 head, the 0331 head will speed things up. I changed just about everything on my 00xj with 254k.oil pump, rod bearings, rocker arms,,,,oil psi would drop to 0-5 at hot unless I ran 4 qts. 20w/50 w/ 2 qts of lucas then it would be like 10 if i was lucky. Dug in again and changed cam bearings, timing chain, chain guide, and lifters, now I run right at 30psi hot with 10w/30. Check this article;


http://www.askamechanic.info/askamec...nt/view/35/47/

RoyalXJ

at 254k i would expect bearings to be worn.

5150mechanic

Maybe, but 45, 70, 140k ? I'm thinking my motor was changed at one time or another but then again the whole jeep would appear to have only 80 or 90k by just looking at it. Cylinders still had very good crosshatch, mains looked new, no scratches in the babbit, All of the rod bearings looked good accept for number 1 which had a little scarring prob from milkshake and the last one in line for oil.

honesT

Just to let you know I have read that you should or must put the stock pickup back in with the new pump Cuz being short that 1/4 inch or so is bad news

But then again I`m no mechanic Just what I`ve read

honesT

Just how fast does the oil make it`s way back down to the pan ?, Do higher RPMs slow the flow? What happens when you are in the Baja flying through the air...

It`s does not seem worth the money to go with the high flow if there is a chance of something going wrong, maybe you go a little longer than usual between oil changes and are missing a quart, would that heat things up ?

honesT

I just bought the stock size Melling oil pump from lordco as My engine has 224,000 Km and that is about average life span for a mechanical pump as the gears wear and leave a gap between the housing losing pressure, Or so I`ve read. I`m sure some it varies from owner to owner, I just bought my Jeep so taking no chances. I had to change my rear main seal and pan gasket anyway.

Just a note: there was plenty of oil on top of my rocker springs when I changed the rocker cover gasket just don`t know how much pressure or volume of oil. Good insurance for 100 bucks.

AFMan

Sorry it took me so long to update. Oil pressure rides higher and for longer now that the Oil pump has been changed, but the problem is still there, so I'm wondering if the Cam Bearings need to be replaced now. Anyone have any thoughts on this?

5150mechanic

I would plan on doing cam bearings but thats just me, if funds allow do a pull out from lkq, reputable wrecker or rebuild. But cam bearings can be done in vehicle.

AFMan

Ok, so what will that run me in parts and labor if I have some one do it roughly? How do I know for sure the bearings are bad. Other than that guage, it sounds and feels fine and strong. I occassionally get a "check engine," light but all the cylinders tested out fine, and it block tested fine. If the cams were bad, wouldn't the block test have revealed that? What happes if I keep driving it as is? I mean, if the cams are bad, what idications will it start showing me? Thanks for the help. Also, what is a pull out from "1kq?" Thx again.

ibanezjeepguy

I really enjoyed reading the article By Richard McCuistian.
Reading this got me wondering...
So if the oil pressure is most likely failing due to a situation with the cam bearings doesn't that mean the low pressure will eventually affect the main & rod bearings being they are supposedly next on the oil train?

My 2000 Grand Cherokee with the 4.0L has about 186K miles on it and I am the 3rd owner. Previous owner told me he had a shop work on the engine and at that time the pump and lifters were replaced and nothing else except the shop told him to run only 20w50 in the engine, my assuming is to keep the problem masked until the engine eventually bit the dust. Being the Jeep lover I am, I drained the old crud from the engine and replaced with Mobil 1 HM 10w30 only to find low pressure around 10 psi at hot idle. Running pressure 1500 rpm+ indicates around 40 and 40 at cold start-up.

whitewonder02

i have a 2000 jeep cherokee 4.0 6 cyl and i had a cracked head but i had that replaced and fixed along with a new radiator(it had a couple small holes in it) then my oil pressre gauge still dropped to 0 when hot so i had the oil pump replaced along with a new pressure sending unit. the jeep runs fine now but it still has the same low oil pressure readings when hot. do i need to replace the oil pump again or is something wrong with the head still?????

anothadayridin

I have a renix and have the. No or low oil pressure. When warm but is around fourty when cold I need answers. Myself. Got six filter royal purple oil new sending. Unit. 95000 miles kinda clueless

country2

lol...scrolled too far down I guess on another thread and somehow got on this one...sorry