Has anyone replaced an oil pump on a 97+ 4.0?

My oil pressure has recently been dropping to zero when the engine got really hot. I put a mechanical and digital guage on it which both read 7psi and not zero. Anything below 10 psi and the guage will always drop to zero. I knew there was a problem but I also knew that it wasn't my sending unit. I realized I needed to replace my oil pump. Once I actually did the research on the install I realized it was much more complex then people had originally informed me.

I made a plan that I would get my cousin(a mechanic) to help me do the swap as soon as he was free, which isn't for 3 weeks. Well, that plan fell apart this morning. I now have 2 huge problems. The first being that my engine seized up on me this morning. It started real rough and then made on odd metalic bang sound and then quickly shut down. I couldn't even begin to get it to turn over after that. The battery, alternator, and starter are all perfect. No oil leaking or visible damage to the block.It is definately inside of the engine that is causing the problem. Waiting 3 weeks for my cousin is no longer an option. My Jeep is my daily driver and I need it up and running ASAP. The other issue is that I still have a bad oil pump. I first need to get the engine running again and then fix my pump. Assuming my engine isn't toast. At 80,000 miles and great maintenance I can't imagine the engine being finished.

What I am looking for is someone with experince swapping out the pump that could maybe give me some step by step instructions or even help me do the swap. I have plenty of beer and I will hook you up with as much food as you can eat. Hell, you can even take a few six packs home afterwards. My superbowl party didn't have as many alcoholics as I had anticipated. Even if you can't afford the time to help, just a simple response of some detailed steps and things to avoid or watch out for would be a great help. The CD I have gives some info on the swap but it also is rather vague in areas and leaves me with a lot of questions. I really hate having unanswered questions when I get into some big project.

What sucks is that is your DD.
Can you get a loaner for a while?
If so, just tear into the project. I have never done an oil pump replacement on an XJ so I can't give any insight on it, but sometimes you spend more time planning out a project than just doing it.
You may get more responses on the 'how' if you post this is OEM tech.

what year is it??????

SlimsXJ said:

what year is it??????

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It is a 2000.

2000&2001 have the 0331 head which cracks between #3&#4 valve spring,open the oil fill cap and look inside for coolant,this happened to mine.coolant takes out all of the bearings causing it to have no oil pressure!!!! David

Pulling the oil pan is not that hard, a bunch of 11mm's and 4 13mm's once the oil pan is off, there is a main cap girdle that goes across all tha main caps. that is held on my 14 or 16mm nuts. From that point you can remove the main caps 19mm I think, and check the bearings, same goes for the rod caps. Oil pump is on the passanger side of the block, note the bulge in the oil pan on that side. I think it is held on by two bolts, but I cant remember. It's really not that hard, especially since it's lifted.

Justin

Edit for you standard guys.

11mm=7/16ths
13mm= 1/2in
16mm=5/8ths
19mm=3/4in

Brad, just gave ya Vince's number to ya......

-Frankie

I did one not too long ago on my brother's TJ......thanks Justin, for finding those torque specs for me! If your oil pressure is that low, I would look at the lower end bearings (rods and mains) while you have the pan off as, they are most likely the culprit of your low oil pressure problem (it was on my brother's TJ) but, it's not that hard to do. The only problem we had was finding an auto parts store that had the bearings (we had to order them) and you can't pre-order them until you tear into it and find out what size bearings you're going to need :dunno: -----------Hans

Cracking the pan is the first step. I changed the pump on mine when i put the front diff thru the pan. Really, its a messy job but nothing to be afraid of. I replace rear mains all the time (only once on mine). Definitly check the head and bearings.

willy51 said:

Cracking the pan is the first step. I changed the pump on mine when i put the front diff thru the pan. Really, its a messy job but nothing to be afraid of. I replace rear mains all the time (only once on mine). Definitly check the head and bearings.

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Did you say that you replaced the rear main seal? Is that something I need to replace at the same time as the oil pump?

Oatmeal said:

I did one not too long ago on my brother's TJ......thanks Justin, for finding those torque specs for me! If your oil pressure is that low, I would look at the lower end bearings (rods and mains) while you have the pan off as, they are most likely the culprit of your low oil pressure problem (it was on my brother's TJ) but, it's not that hard to do. The only problem we had was finding an auto parts store that had the bearings (we had to order them) and you can't pre-order them until you tear into it and find out what size bearings you're going to need :dunno: -----------Hans

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Do you remember what size bearings were needed? How were you able to tell the bearings were shot. I want to make sure to repair/replace anything I can when I have the pan off. There is no reason to have to deal with digging back into the pan later, if I can fix it all at the same time.

id double check the oil sending unit just to make sure

I can not get this engie to turn over. Any ideas on getting a seized engine to crank over?

bhicks said:

Do you remember what size bearings were needed? How were you able to tell the bearings were shot. I want to make sure to repair/replace anything I can when I have the pan off. There is no reason to have to deal with digging back into the pan later, if I can fix it all at the same time.

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It'll be stamped on the bearing shells ie....std, .010, .020,.030......meaning: standard (crank has never been ground), .010 (crank has been ground .010" undersize........)

bhicks said:

I can not get this engie to turn over. Any ideas on getting a seized engine to crank over?

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Oh, I didn't notice that in your previous post. I hate to say it but, low oil pressure and a seized motor dosen't sound like good news :dunno: ----------Hans

Oatmeal said:

It'll be stamped on the bearing shells ie....std, .010, .020,.030......meaning: standard (crank has never been ground), .010 (crank has been ground .010" undersize........)

Oh, I didn't notice that in your previous post. I hate to say it but, low oil pressure and a seized motor dosen't sound like good news :dunno: ----------Hans

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I did eventually get the engine to turn over, but it still hasn't started. I am in the middle of replacing a whole bunch of stuff. I am replacing the oil pump, fuel pump, coil pack and spark plugs, oil pick up, battery, and a few other small things. I dont know if these things will help me get the engine started, but I figured it couldn't hurt.

Rear mains are notorious leakers. if you have the pan off you may as well replace it.

willy51 said:

Rear mains are notorious leakers. if you have the pan off you may as well replace it.

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I'm a step ahead of you. I have the rear main seal sitting on my garage floor ready to go in with all the other new stuff.

so you got the engine to turn over? Hmmm, mine did that ( civic not Jeept ) and when i tore it down it had the thrust washer jammed good between the main girdle and the block. Since you mentioned you got it to turn over im guessing it wasnt that. though it still could be a spun bearing. The loud noise you describe cant be good. So im kinda stumped as to what cause it to sieze up. hmmm.....