• Welcome to the new NAXJA Forum! If your password does not work, please use "Forgot your password?" link on the log-in page. Please feel free to reach out to [email protected] if we can provide any assistance.

Main Or CAM Bearings?

M

mpncsnhs

NAXJA Forum User
Location
PA
Hoping someone could clear some confusion on my part. My 2000 xj has consistantly low oil pressure (around 5psi hot idle, 20psi cruising) my ? is would just replacing the main bearings help and prolong the life of my 4.0 or do the cam bearings have to be replaced. If replacing the main bearings are not going to help than i will not replace them, but if it will give me a couple of years then i will do it, but if the only thing that will help the oil pressure is to replace the cam bearings then i will not fix it and just get rid of it. Anyone out there no the answer?
 
You have 20psi on a 2000? How many miles? Please tell me it's over 200K!

Anyway, cam bearings just don't have the affect on oil pressure that the main and crank rod bearings have. If those bearings are bad, do a whole crank kit (crank + bearings as a kit) if one is available. Why do the job 1/2 azzed? If it has tons of miles, do a complete rebuild and get it over with. The only reason I wouldn't do that is if the body is junk.

Another option is a good junk yard engine. Many of those engines can be got in good shape for cheap. Also check the for sale in your chapter. 4.0Ls come up every once and again as people parting out a rig.
 
try changing your oil, dont go thicker, just do a fresh change. Lots of times you will lose a little pressure when the oil starts to break down. Mobile One is especially bad at this.

you can also try changing the sender. It coudl be going bad, at at about 30 bucks it is a lot cheaper and easier than a main bearing/crank job
 
make sure coolant isn't getting in slowing killing your motor. Ever overheat or have to add a little coolant
 
So everyone knows background, had a cracked head and didnt catch it soon enough that is i'm sure what is causing the issue. I've tried differant things like putting heavier oil in and it helps but is just a band aid, thicker oil is not fixing my bearings. I use a mopar filter and will replace the main and rod bearings because i will not have to pull the engine but i will not put cam bearings in it, i will just run it till it dies and sell it needing a motor (i only use the jeep as a beater vehicle because i have a new Titan). I just want to know if doing the mains and rods will help. BTW Oil pressure readings come from a Mech Guage.
 
So I was right! 0331- What Idea's you need? Replace your head, then over haul your bearings as you wish. Run short oil change intervals and pray. Your oil is getting contaminated with the sodium from the anti freeze, killing your bearings (ALL OF THEM) Your lead and copper numbers are probably through the roof.
 
Antifreeze doesn't like bearings very well. Unfortunately, the block's really gotta come out for cam bearings. I guess you could attempt to do it in chassis, but the trans has to be off for access to the rear cam soft plug. Yank it out and fix it right.
 
I had the same problem. Water in the engine as well low oil pressure. I did both the rod and main bearings. My rod bearings where shot. I plastic gauged it and put new bearings in. Helped alot oil pressure back to normal.
 
So replacing the rod and main bearings will help, i can have a mechanic buddy do it fairly resonably and will put the money into the main and rod bearings but having to spent the labor to pull the engine and replace cam bearings isnt going to happen, i've got my money out of the jeep and dont really need it. I have already repaired the head issue and havent had anymore problems other than the oil pressure has bothered me. My mechanic says the mains can be changed without pulling but i didnt ask about rod bearings, can they?
 
AERA minimum oil pressure: 13psi.
 
yes rods and main can be done with out pulling the engine. Just drop the oil pan. Hope you have a lift on your jeep makes it alot easier. If not your gonna have to undo the shocks and swaybar and let the front axle hang to get the oil pan out. Also if you plan on doing that replace the rear main seal while there.
 
You must log in or register to reply here.

Similar threads

S
Scratched bearing while replacing rear main seal
Replies
3
Views
1K
waxer
waxer
O
0331 Strikes Again...?
Replies
11
Views
296
Ol Blue
O
M
Oil pressure question
2
Replies
26
Views
3K
Money_Pit_Incoming
M
U
Electrical issue
Replies
6
Views
2K
UltimateG
U
cherokeefan_1
2000 4.0 build questions
Replies
5
Views
2K
75SV1
7
Back
Top