cheap rebuild options??

[Muad'Dib]

PU tube was very tight, and i didnt inspect the pump at all i just put it in... Well i take that back, i didnt open it up, but i did clean it with warm soapy water, and then with brake cleaner.

[Muad'Dib]

I started it up just now (the first time since last night) and she purred like a kitten. Oil pressure shot to 60, but after about 5-8 seconds went to 40 and slowly dropped down to 20. This was all while continuing the breakin process at 2500 RPMS. If i let it go down to even about 1100 RPMS, the pressue stays around 20, but if i let it drop down to idle pressure drops to 0. Another fact, when the oil pressure reaches 20, the chatter from the engine is just like what i would expect to hear in a engine that has 200,000 miles.

Maybe its the cheap ass wally world oil i used for breakin since i knew i had to change it right away anyway. IIRC, it was 5w-30. Should i change the oil and try something much heavier? like straight 30wt? or am i just screwed?

[shawnxj]

first i'd put a new oil pump in then i'd use a quality oil instead of that crap your using and make sure you get a gasket on that distributor. would suck to grenade a motor you just rebuilt from using an old pump and inferior oil

[Muad'Dib]

I just checked the old rod bearings that i replaced... great! Once says STD, and the other says .001 .. but when i plastigauged, they squished to have ~.002 clearance.

My plan of action thus far is to replace my oil and filter. If the problem still exists, then ill drop the pan, and inspect the rod bearings while replacing the oil pump.


Did i mention this is my DD that has been down??

[4.whoa]

Did you use any brake in additive? If you don't have any use something like rotella 15w40 diesel oil. Its thicker & has good zddp levels to keep the lifters alive through brake in.

[SilverXJ]

That pickup tube can be tricky.. One was so lose that it let air in the system... on this past pump I went through 3 before one fit securely.

I missed your description of the valve noise when the oil pressure drops to 20... that is what mine sounded like with the poor fitting pickup.. it let air into the system and air in to the lifters. Check the pickup tube and check the pan clearance.

You should have used a ZDDP additive in the oil, but I don't think that is your problem.

[Muad'Dib]

I did use additive with the initial oil i put in the system.

I just changed the oil to 15w-40 CI-4, and it sounded really good on startup oil pressue was like 60... quickly dropped down to 40, and this time took a lot longer to get to 20. Idle stayed around 10, but slowly dropped down to 0. Im at my wits end.. i really needed this back on the road. A month without my daily driver has been hell, and now its probably going to be much longer without it.

The clackity clack i hear is pretty much non existant when oil pressure is at 40sih.. but once it drops to 20 and lower it just gets worse.. and will even do a light backfire if i rev it fairly quickly (not WOT .. just quick). Im starting to wonder if the cam is wiped... would the cam being bad cause low oil pressure? i thought only bad cam, main, or rod bearings would.

Im thinking of pulling the engine and dumping the non existant money i have into it. It would help if i had a Job, and i wasnt going to get evicted from my house!

[IH 392]

How did you check the clearance between the pan and pickup screen?, if it's too close they can do stupid things like that.

[Muad'Dib]

How did you check the clearance between the pan and pickup screen?, if it's too close they can do stupid things like that.

I didnt .. i never have i guess i didnt know that i needed to...

[IH 392]

I've gotten away with putting my protractor on the block pan rail and matching the pickup to it, a straight edge across the pan rails measured to the bottom of the sump and then the pickup tube and figure in about 3/8" clearance works ok too.

I had a '56 IH with a six cylinder that I over hauled that had bearings in it that were IIRC .003" under and replaced with STD bearings, had similar symptoms to your engine but it took several miles of driving for the oil pressure to go away.

[SilverXJ]

Silly putty on the pickup. Then put pan on, remove pan and measure silly putty.

[4.whoa]

According to my chilton's manuel (I still don't have a FSM ) main bearing clearance should be .0010-.0025 and rods .0010-.0030 so you're not loosing oil pressure there. the last time mine was apart the pickup screen had what looked like alot of paper or lint fibers in it. Don't know where from,but it was a pita to get it all out.

[Muad'Dib]

I guess ill have to pull it and do an inspection.

[IH 392]

last time mine was apart the pickup screen had what looked like alot of paper or lint fibers in it. Don't know where from,but it was a pita to get it all out.

NEW screens are readily available for AMC/Jeep engines and relatively inexpensive too, the only time I reuse one on any engine is if one is no longer available.

[lafrad]

Have to checked to make sure you are getting proper drainback from the top of the engine?

Maybe you are pumping all your oil up to the head and just starving the pan of oil?!?