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Amc 360 Cj5 oil pressure dropping
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White70JavelinSST View Drop Down
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Points: 4867 		Post Options Post Options   Thanks (0) Thanks(0)   Quote White70JavelinSST Quote  Post ReplyReply Direct Link To This Post Posted: Aug/24/2016 at 12:12pm
Buy, beg to borrow or just get another oil pressure gauge that is known to function correctly.

or, test the one you have with another pressure source like compressed air or on another vehicle.

Try that first. I've had bad gauges fool me before.

Remember do the easy things first.

Don't pull it apart until you know that is the last resort.

and for the record, AMC V8 engines are not plagued with oiling issues. That is a myth/fallacy. I have a 70 304 V8 with over 130,000 miles on it, never been rebuilt. Holds 22 or so psi at hot idle, 50 psi at 1800 rpm hot. Cold idle is 60 psi. Tell me how that constitutes being plagued with oiling issues. It appears to me the problem is bad rebuilds, or lack of maintenance.



Edited by White70JavelinSST - Aug/25/2016 at 3:31pm
70 Javelin SST, second owner, purchased 1972
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Boris Badanov View Drop Down
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Points: 4210 		Post Options Post Options   Thanks (0) Thanks(0)   Quote Boris Badanov Quote  Post ReplyReply Direct Link To This Post Posted: Aug/24/2016 at 4:06pm
The shift in oil pressure power on to power off hints at mains.
I have wiped out cam bearings and that never happened.
Just low oil pressure and noise.
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Greyhounds_AMX View Drop Down
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Points: 1268 		Post Options Post Options   Thanks (0) Thanks(0)   Quote Greyhounds_AMX Quote  Post ReplyReply Direct Link To This Post Posted: Aug/24/2016 at 5:38pm
Maybe the little plastic blob on the pickup finally decided to bust off and let the oil pump pickup get sucked down to the bottom of the pan.
1968 AMX 390 w/T5
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one bad rambler View Drop Down
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Points: 2007 		Post Options Post Options   Thanks (0) Thanks(0)   Quote one bad rambler Quote  Post ReplyReply Direct Link To This Post Posted: Aug/24/2016 at 5:59pm
sounds like it`s staring for oil....check the pick up
68 AMX 390 4 Speed,68 American,64 American 2 Door Wagon Altered Wheelbase,78 Concord Build 360,727,8.8
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Green AMX View Drop Down
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Points: 521 		Post Options Post Options   Thanks (0) Thanks(0)   Quote Green AMX Quote  Post ReplyReply Direct Link To This Post Posted: Aug/24/2016 at 7:33pm
Change the oil & filter and cut the old one to see if theres any metal in it
69 AMX 390 4speed go pack
72 Javelin 360 auto(sons)
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Boris Badanov View Drop Down
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Points: 4210 		Post Options Post Options   Thanks (0) Thanks(0)   Quote Boris Badanov Quote  Post ReplyReply Direct Link To This Post Posted: Aug/25/2016 at 4:52am
Originally posted by Green AMX Green AMX wrote:

Change the oil & filter and cut the old one to see if theres any metal in it


There always is.

If you do not know how to decipher the crap
you will just scare yourself.
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Kd34 View Drop Down
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Points: 8 		Post Options Post Options   Thanks (0) Thanks(0)   Quote Kd34 Quote  Post ReplyReply Direct Link To This Post Posted: Aug/25/2016 at 7:25am
It looked to be reading oil level incorrectly, it was just whiping the edge of the pan or something is what I was told. Anyways, replaced the dipstick and it was real low on oil. Poured two quarts in and it went back to 60 psi on cold starts. So the slow decrease in pressure was from the steady loss of oil. So now I have to figure out why it's losing oil.
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dwg86 View Drop Down
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Points: 66 		Post Options Post Options   Thanks (0) Thanks(0)   Quote dwg86 Quote  Post ReplyReply Direct Link To This Post Posted: Aug/25/2016 at 10:09am
What intake do you have? I am doing a rebuild on my 401 that only had 1000 miles on it. I sucked all the oil out through the PCV valve. I have an eldbrock air gap intake with the lifter valley oil line. I didn't use the valley pan gasket nor did I have the stock intake to remove the baffle from. I only had the little splash guard that came with came the air gap intake. All that oil splashing around got sucked through the PCV valve. I moved the PCV valve to the valve cover with a baffle. That solved my problem, but unfortunately the damage had been done. Only a few miles later and she started knocking. The engine is back in the machine shop again, with a scored #8 piston, cylinder wall, and trashed bearings. I was already .040 over, but the cylinder will clean up at .045. I'll be using Wiseco .045 Pistons.
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53w View Drop Down
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Originally posted by dwg86 dwg86 wrote:

What intake do you have? I am doing a rebuild on my 401 that only had 1000 miles on it. I sucked all the oil out through the PCV valve. I have an eldbrock air gap intake with the lifter valley oil line. I didn't use the valley pan gasket nor did I have the stock intake to remove the baffle from. I only had the little splash guard that came with came the air gap intake. All that oil splashing around got sucked through the PCV valve. I moved the PCV valve to the valve cover with a baffle. That solved my problem, but unfortunately the damage had been done. Only a few miles later and she started knocking. The engine is back in the machine shop again, with a scored #8 piston, cylinder wall, and trashed bearings. I was already .040 over, but the cylinder will clean up at .045. I'll be using Wiseco .045 Pistons.


That strange how some engines suck oil with the air gap and some don't? I have no oil suck problems. I did use valley pan gasket just cut clearance so oil line would clear. I think i also pack splash gaurd cavity with steel wool? I also made my own baffle now that i think about it?

Edited by 53w - Aug/25/2016 at 5:26pm
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Kd34 View Drop Down
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Points: 8 		Post Options Post Options   Thanks (0) Thanks(0)   Quote Kd34 Quote  Post ReplyReply Direct Link To This Post Posted: Aug/29/2016 at 12:11pm
So after adding the oil, the cold pressure is around 60 to 50. But the needle on the guage looks to still be bouncing. It doesn't remain constant at 60 but will bounce between 40 and 60. Idk if this could be air in the line?
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