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post #1 of (permalink) Old 12-23-2001, 11:50 AM
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401 oil pressure

I got the 401 running and it does the same thing as my 304 did, when you start the engine the oil pressure is good 45-50 PSI after the engine warms up the oil pressure drops below 10. Now this sounds like the oil pump case is worn, right? So is it worth the $180 to replace the timing chain cover? or is there another way to get my oil pressure up. my 304 was the same way and I understand it is a common promblem with these engines. I ran that 304 like that for a long time because I didn't really care if I blew it up or not. It kind of worry's me with the 401. Thanks in advance for your guys help.

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post #2 of (permalink) Old 12-23-2001, 12:30 PM
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Re: 401 oil pressure

buy the new timing cover also stretch the pressure spring a little first and try that

jeep the first 4 wheel drive the only 4 wheel drive
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post #3 of (permalink) Old 12-23-2001, 05:35 PM
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Re: 401 oil pressure

If you intend to do any off roading at all bite the bullet and replace the cover. Mine had your systems plus developed a nasty off-road habit of losing it's prime, therefor ALL oil pressure. The first time I thought it was a fluke, the second time was enough for me. If it loses it's prime you have to pull the pump cover and pack it full of grease to get things going again. Sucks on the trail plus just the thought of my poor engine was enough to convince me. Now my 304 idles at about 20-25psi and runs about about 50-60 down the highway.

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post #4 of (permalink) Old 12-26-2001, 08:04 AM
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Re: 401 oil pressure

Also get new gears and cover plate. Replace it all as a set.

76 CJ5
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post #5 of (permalink) Old 12-26-2001, 10:16 AM
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Re: 401 oil pressure

I thought I had saved a link to a web site that sold high-pressure high-volume AMC oil pumps but I canít find it now. Do a search for the past 6 months on oil pressure and you find it. The AMC manual says it should have 25 psi at idle, mineís run 20 psi.

If both your engines had 10 psi after they are warmed up than I would also check your pressure gauge. It sounds funny that both motors have the same problem.

78 CJ7 304V8,TH400,Dana 300 Twin stick,Custom HD-WT AMC20 detroit locker 4:10,D30 ez-locker 4:10,Built NOT Bought.
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