i have a 95 xj, I found out the owner before me put in a 4.0 from an earlier cherokee. It ran great and had great oil pressure, but it had a rod knock. So I changed the rod bearings. not knowing how many miles where on the engine and while i had the engin open, I thought i would change the main bearings. I put it all back together and started it, it had no oil pressure and a knock coming from somewhere. So I figured the knock was from not having oil pressure. So I changed the oil pump to a high flow oil pump and it still has no oil pressure and the knock is still there. Any thoughts on what it may be?

 

..... ever done bearings before?

 

Well from the sound of things...it may be......time for a rebuild?

 

I have a feeling there's either a spun bearing or an oil hole not lined up. They can be installed backwards.

 

Well with things knocking and no oil pressure..... its not gonna be pretty....

 

Im gonna agree with everyone else, maybe its time to let somebody that knows what theyre doing to fix it correctly.

Have you actually checked the oil pressure or are you just reading the guage? Rod caps and main caps have to go back in the exact location they came from, oriented the same way as before. Same with rod caps. There are more than a few ways to install bearings incorrectly also...

 

That's the thing. He had pressure, replaced the bearings, now he doesn't have pressure. Take em out and do it again. Main caps should be numbered. Pay close attention to the oiling passages and check the clearance with plastiguage.

 

I have done bearings a few times before. first time I have done it with the engine still in, and the first time I have had any problems. the caps all went back in the same way. the new bearings went in the same way that I pulled then out. but im not afraid to pull the pan and double check my work. I will let you guys know what i find. thank you for replying

 

Good luck. Wasn't trying to sound like a Dick BTW... realized that might have come off bad.

 

We know you are an Angil slick . Not lining up the holes would make higher oil pressure... for a minute, eh? I've never been there on one of these, but don't you need to remove the oil pump to get the pan off? Is the pump a gasket or an "0" ring? I don't think it comes in the pan set whatever it is. I'd be looking at that. (and not running it). X2 on the plastagauge, but you already have your bearings so that's ....done. Mine has a slight rod knock with 10-40 that goes away with straight wt 30W Castrol. 262K, I warm it up.

 

My question is did you make sure to prime your new oil pump? Or prime it after you removed it? Remove dizzy and prime it with a drill. Wouldn't hurt to try right?

 

Oh ya... I'm constantly brain farting... maybe you lined the hole up too well.

 

X2 on the prime. OK team, (yea, even you with the gas). How does the pressure relief valve work?...did his new high flow pump jam the old thing open?

 

may be a stupid question, but did compare the old bearings to new bearings? jeep is bad about doing little changes like ring size and such for no apparent reason. ran into that problem with my buddys 00 with the piston rings