No Pressure after engine warms

[mwouda]

I have a 78 304 with a fresh build. After about 5 hours on engine, once it warms up I loose oil pressure. When cold, it idles at 50 psi, once the temp rises to 180, it drops to 2-5 psi. I know its not the sender or guage, because I also have a fuel pump shut off sender on same oil port. The fuel pump does shut off, at that low of pressure. It has new timing cover, new pump, oil filter relocation, all Bulltear.

Any Help would be greatly appreciated.

[jeepsr4ever]

Something is seriously worng with your build. Either a cam bearing has spun, a block plug is leaking or a lifter is shot. You need to put together a parts list with part numbers to allow any kind of look at the combo. The parts you got from us will not give you any pressure if the rest of the system isnt working well. Where are you picking up pressure? (stock location or other?) Also your cold idle is decent if not a little high.

[mwouda]

Assuming something is seriously wrong with my build would be the same as assuming there is something seriously wrong with your parts. I was not in any way thinking my issues were the result if defective parts. I have always been happy with my Bulltear purchases. My intent was solely to consult with the AMC gurus on possible scenarios. It's been awhile since I've been on this forum, but from what I remember this was the place to get that information without a guy getting his build ridiculed. Again, sorry if you feel I insulted your products, Matt.

[jeepsr4ever]

Their is something to blame is my point. I can tell you that I design the parts and have my hands in the machining. I can guarantee that it if goes out our door and we made it the part will do what it was intended. The oil relocation kits are perfect I can guarantee that much. That being said I dont mind opening any discussion and dont take it personally. You have a problem with pressure after the engine warms up so their is a problem with the parts on the block. I just gave you suggestions.

[jeepsr4ever]

Sometimes that can be the fault of the pickup tube not being screwed in all the way but you would see a dip in pressure as you raise the RPM if that was the case. Sometimes its a broken timing cover gasket as well.

[mwouda]

Thank you for your response. I know Bulltears history and reputation, thats why I am here and not on other sites. I love your parts and will continue to use them.

A little more info, I have two sending units at factory locations using a tee. One is for fuel pump shut off and the other is guage sending unit. Cold idle I have 40-50 psi, at temp I have less than 5 psi until i bring it just above idle. At 1200 rpm, I am back up to 40 psi. Back to idle, less than 5 again.

Just looking for ideas before i tear this engine down and redo cam bearings. Just thinking outloud, the filter relocation i got, I used the original bypass, which seemed to move freely in the bore, and the spring "seemed" fine. Is this all right? When i first got the block back from machine shop and started to assemble, i had no oil pressure. I found the machine shop did not reinstall the galley plugs. I installed the two in the front of the valley. Is that all the plugs or could I be missing one? Could the pickup tube have a crack that could be opening with temperature?

Thank you for your time!

[jeepsr4ever]

There are two plugs behind the timing gear that may be missing.

[jeepsr4ever]

What RPM are you idling at and what oil are you using?

[mwouda]

idle is at 700 and using valvoline 10w-30. Not much difference in pressure unitl i get to 1200, then jumps up. A little high for idle i thought.

I dont know about plugs behind timing cover. If they didnt put in valley, i doubt they are there, and I didnt notice. Would this cause my symptoms?

[jeepsr4ever]

Its a horse a piece because you are idling low using lighter oil so once it hits that pump efficiency band the pressure should jump quite a bit.