88 4.2 I6 LOW oil pressure

[wrangler rider]

sorry dont geton here alot, yeah im buying a new crank, worked 20hours in the past 2 days so now i can afford it, but heres what it boiled down to to trun the crank its AMC 150 plus AMC 150 worth of bearings, or a used crank from the junk yard 26 and AMC 150 worth of bearings, or a brand new crank with all the bearings from napa is 210, so kind of a no brainer lol, and the cam new is lik 117 and i dont know how much the bearings are, but god willing the cam will be ok

i get my truck back tommarrow so the chargers goin to the body shop asap, and while thats gone im going to pull the motor and rebuild it because i have the space while its gone

and i think i know why this happend after days of reminising about the rebuilds, after the first rebuild i have the old oil pump drove for about 20 miles or so with no oil pressure, i put the gauge on it and had none so thats how i know that, and because i had the wrong rings in it i think that ruined the rod bearings causing the low oil pressure and failing of the main bearings, but thats just what i got from thinking about it

thanks yall

 

[wrangler rider]

so apparently all the 4.0 owners like to stroke their motors and use AMC 258 i6 / 4.2l cranks, which means no cores, and inturn means there are no AMC 258 i6 / 4.2l cranks availble AT ALL, no remans, no new ones, nothing, napa, carquest, advanced, auto zone, the truck shops, absolutely noone can find a crank for my jeep, so looks like im going to have to waste a $100 more to hopefully fix my bad crank, if anyone knows where i can get a crank for a decent price let me know, id really rather not reuse my hunk of junk,its already .010 mains and .030 rods

 

[wrangler rider]

oh yeah car quest called the #1 crank remanufactureor in florida and guess what? NOTHING AT ALL
Even jeep cant get them, they apparently quit making them and are discontinued :madjeep:

 

[fzsk4p]

oh yeah car quest called the #1 crank remanufactureor in florida and guess what? NOTHING AT ALL
Even jeep cant get them, they apparently quit making them and are discontinued :madjeep:

Fear not, Scat has you covered

Michael Sutton
Crank Sales
SCAT Enterprises, Inc.
(310) 370-5501 EXT.191

Scat Crankshafts

 

[NorCalChris]

If I was you I'd go with the scat crank. And do a FULL rebuild correctly. Measure everything. Double check packages to make sure you have the right parts, do it in a clean environment, and use a good torque wrench. If you need help just post up and ask.

 

[Cheepjeep85]

Fear not, Scat has you covered

Michael Sutton
Crank Sales
SCAT Enterprises, Inc.
(310) 370-5501 EXT.191

Scat Crankshafts

I was under the impretion they quit making those. I guess not, that's good to know anyway.

Drooooid...2

 

[Rescue Diver]

You probably have a little too much clearance for your rod, main, and cam bearings. This is pretty normal. Most old Jeep I-6 motors have decent pressure when driving but next to none at idle. An engine will not be hurt by only having a few pounds of pressure at idle, but if it makes you feel better, install a new high volume oil pump. That'll make it read better. And don't confuse a "high pressure" pump with a "high volume" pump. The high pressure pump just has a stiffer spring in the bypass valve, while a high volume pump is literally taller so it moves more oil than a standard pump. If you go this rout, you'll also have to get a new oil pickup so it'll still fit in the pan with the taller pump.

 

[Rescue Diver]

so apparently all the 4.0 owners like to stroke their motors and use AMC 258 i6 / 4.2l cranks, which means no cores, and inturn means there are no AMC 258 i6 / 4.2l cranks availble AT ALL, no remans, no new ones, nothing, napa, carquest, advanced, auto zone, the truck shops, absolutely noone can find a crank for my jeep, so looks like im going to have to waste a $100 more to hopefully fix my bad crank, if anyone knows where i can get a crank for a decent price let me know, id really rather not reuse my hunk of junk,its already .010 mains and .030 rods

I see complete AMC 258 i6 / 4.2l motors in need of a rebuild for sale on craigslist for around $100 all the time. That's how much I paid for mine. You could just buy one of those for the crank?

 

[NorCalChris]

I see complete AMC 258 i6 / 4.2l motors in need of a rebuild for sale on craigslist for around $100 all the time. That's how much I paid for mine. You could just buy one of those for the crank?

I'd go that route if you could. But it still would need to be checked and polished. On a side note, I wish I lived near you, the last AMC 258 i6 / 4.2l on craigslist here went for 400.

 

[Rescue Diver]

I'd go that route if you could. But it still would need to be checked and polished. On a side note, I wish I lived near you, the last AMC 258 i6 / 4.2l on craigslist here went for 400.

Must be a california thing. I run across them all the time for way less than that.

Did you say you're building a stroker? I think you'll also need a spacer for the harmonic balancer if I remember correctly. I read that there's something different about the length of the front of the crank shaft between a 4.0 and a AMC 258 i6 / 4.2l .

I'll have to go read up on it again before I start building my stroker. I don't plan to do it until maybe next year. My AMC 258 i6 / 4.2l is running great with the new 4.0 head swap, so I'm in no hurry.

 

[Old Dog]

There's nothing wrong with being .030 under as long as you get the right bearings. Heck back in the day they welded the jurnals and than reground them all the time. I'm sure they still do as there's a lot of cranks that are not made anymore.

 

[wrangler rider]

well learn from this, AMC 258 i6 / 4.2l cranks are not availible, if you do it youll probly get a junk yard one which it ended up costing me almost 300$ with my own crank for everything so guess 300 plus crank to do it all right