lower crank/ rod bearing help
CF Veteran
Joined: Jul 2012
Posts: 1,395
Likes: 1
From: SD
Year: 1998
Model: Cherokee
Engine: 4.0
CF Veteran
Joined: Aug 2011
Posts: 10,489
Likes: 24
From: Nor-Cal Coast
Year: 90,84
Model: Cherokee
Engine: 4.0,2.5
Just tagging the tread. Btw, renix folk should see this Cruiser did:
https://www.cherokeeforum.com/f51/cruiser54s-mostly-renix-tips-153657/
https://www.cherokeeforum.com/f51/cruiser54s-mostly-renix-tips-153657/
Thread Starter
Senior Member
Joined: Jan 2012
Posts: 1,001
Likes: 0
From: Memphis tenn
Year: 88
Model: Cherokee
Engine: i6 4.0
Originally Posted by cruiser54
It's in the block but you can't see the bearings without engine removal and disassembly.
Have you manually checked the oil pressure yet or the flexplate bolts?
CF Veteran
Joined: Aug 2011
Posts: 10,489
Likes: 24
From: Nor-Cal Coast
Year: 90,84
Model: Cherokee
Engine: 4.0,2.5
Yea bud. The torque converter to flex plate bolts can loosen and cause a real racket. There is a little dust plate facing the pan with a few 1/2 inch bolts. Gives you access to them. Good thing to check first.
Last edited by DFlintstone; Nov 9, 2012 at 02:12 AM.
Newbie
Joined: Oct 2012
Posts: 16
Likes: 0
From: Massachusetts
Year: 1998
Model: Cherokee
Engine: 4.0
Here is another vote for a complete rebuild or replace engine.
If you really want to diagnose it yourself as a learning experience you can start with checking the main and rod bearings. You need a Factory Service Manual or equivalent repair manual.
At a MINIMUM, you need to remove the oil pan, remove the lower bearing caps and inspect. If you have visual grooves and/or burn marks you already need to remove the crank.
If for some miraculous reason they actually appear good, you can check the oil clearance with plasti-gauge. You can get that at the auto parts store. You simply follow the instructions on the package. It's wax string basically that will compact when you re-install the bearings and caps. Then you remove them again and measure how much it compacted and compare it to the gauge on the package. That will give you a good indication of your oil clearance. Then compare that to what the manual recommends to see how much wear you are experiencing.
I have to say, after rebuilding several engines, you are almost certainly going to see visible grooves AND burning as well as significant wear on at least one bearing from what you have described so far.....knocking, now smoking and no oil pressure.
I hope your luck is better than mine.
If you really want to diagnose it yourself as a learning experience you can start with checking the main and rod bearings. You need a Factory Service Manual or equivalent repair manual.
At a MINIMUM, you need to remove the oil pan, remove the lower bearing caps and inspect. If you have visual grooves and/or burn marks you already need to remove the crank.
If for some miraculous reason they actually appear good, you can check the oil clearance with plasti-gauge. You can get that at the auto parts store. You simply follow the instructions on the package. It's wax string basically that will compact when you re-install the bearings and caps. Then you remove them again and measure how much it compacted and compare it to the gauge on the package. That will give you a good indication of your oil clearance. Then compare that to what the manual recommends to see how much wear you are experiencing.
I have to say, after rebuilding several engines, you are almost certainly going to see visible grooves AND burning as well as significant wear on at least one bearing from what you have described so far.....knocking, now smoking and no oil pressure.
I hope your luck is better than mine.
Thread Starter
Senior Member
Joined: Jan 2012
Posts: 1,001
Likes: 0
From: Memphis tenn
Year: 88
Model: Cherokee
Engine: i6 4.0
Originally Posted by maxpower_hd
Here is another vote for a complete rebuild or replace engine.
If you really want to diagnose it yourself as a learning experience you can start with checking the main and rod bearings. You need a Factory Service Manual or equivalent repair manual.
At a MINIMUM, you need to remove the oil pan, remove the lower bearing caps and inspect. If you have visual grooves and/or burn marks you already need to remove the crank.
If for some miraculous reason they actually appear good, you can check the oil clearance with plasti-gauge. You can get that at the auto parts store. You simply follow the instructions on the package. It's wax string basically that will compact when you re-install the bearings and caps. Then you remove them again and measure how much it compacted and compare it to the gauge on the package. That will give you a good indication of your oil clearance. Then compare that to what the manual recommends to see how much wear you are experiencing.
I have to say, after rebuilding several engines, you are almost certainly going to see visible grooves AND burning as well as significant wear on at least one bearing from what you have described so far.....knocking, now smoking and no oil pressure.
I hope your luck is better than mine.
If you really want to diagnose it yourself as a learning experience you can start with checking the main and rod bearings. You need a Factory Service Manual or equivalent repair manual.
At a MINIMUM, you need to remove the oil pan, remove the lower bearing caps and inspect. If you have visual grooves and/or burn marks you already need to remove the crank.
If for some miraculous reason they actually appear good, you can check the oil clearance with plasti-gauge. You can get that at the auto parts store. You simply follow the instructions on the package. It's wax string basically that will compact when you re-install the bearings and caps. Then you remove them again and measure how much it compacted and compare it to the gauge on the package. That will give you a good indication of your oil clearance. Then compare that to what the manual recommends to see how much wear you are experiencing.
I have to say, after rebuilding several engines, you are almost certainly going to see visible grooves AND burning as well as significant wear on at least one bearing from what you have described so far.....knocking, now smoking and no oil pressure.
I hope your luck is better than mine.
CF Veteran
Joined: Apr 2012
Posts: 5,302
Likes: 23
From: Wisconsin
Model: Cherokee
Valve seals have no effect on oil pressure. At worst they'll create smoke.
If you have zero oil pressure, knocking noises and similar stuff going on, it isn't valve seals. Either the oil pump is shot, or the bearings are. Or both.
If you have zero oil pressure, knocking noises and similar stuff going on, it isn't valve seals. Either the oil pump is shot, or the bearings are. Or both.
::CF Moderator::
Joined: Aug 2011
Posts: 43,971
Likes: 1,578
From: Prescott, Az
Year: 1990
Model: Cherokee (XJ)
Engine: 4.0
Man, not wanting to sound insulting, but are you thick in the head or something? You've got multiple threads going on with good people giving you good advice, and you still ignore and persist. Give up. That motor is history.
Senior Member
Joined: Aug 2011
Posts: 760
Likes: 6
From: Landers, CA
Year: Several
Model: Cherokee
Engine: 4.0
Interesting how some folks think loose flexplace bolts create low oil pressure!
Please explain HOW!
He's looking for some magic cure - he needs to see a shink!
Please explain HOW!
He's looking for some magic cure - he needs to see a shink!
Thread Starter
Senior Member
Joined: Jan 2012
Posts: 1,001
Likes: 0
From: Memphis tenn
Year: 88
Model: Cherokee
Engine: i6 4.0
Originally Posted by rrich
Interesting how some folks think loose flexplace bolts create low oil pressure!
Please explain HOW!
He's looking for some magic cure - he needs to see a shink!
Please explain HOW!
He's looking for some magic cure - he needs to see a shink!