Oil pump questions

Hi all. I have a '76 CJ-5 with the 304 engine. I recently did quite a bit of work to it, replacing lifters, intake, carb, and ignition. Now it starts right up and runs GREAT. Idles great, good power, etc, etc... BUT my oil gauge is reading pretty low pressure and it worries me. I don't know much about the history of this Jeep at all so I was wondering a couple of things. First of all can anyone point me to a source online to buy a high-volume oil pump for my Jeep, and secondly how hard is it to swap out an oil pump on my engine? Thank you in advance for input.

Reply to
Shaggie
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well, it should be pretty easy-you'll probably have to drop the oil pan to get at it. a couple of screws will be holding it in (if it's anything like the 258). try looking at quadratec, 4wd or tellico4x4. call around to napa too. have you checked the sending unit? that maybe your problem...

Reply to
serg

Yup, a very common problem with electric oil pressure guages. I keep an el cheapo mechanical guage around to test engines with.

Chris

Reply to
c

Reply to
L.W.(ßill)

"c" wrote in news:KL%kc.13933$u snipped-for-privacy@twister.rdc-kc.rr.com:

The gauge I have now is a mechanical one with the high-pressure oil line running from the "sender" to the gauge. It is a cheap gauge so I suppose the gauge itself could be bad.

Reply to
Shaggie

What are you running hot and cold for pressure?

Mike

86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00 88 Cherokee 235 BFG AT's
Reply to
Mike Romain

Mike Romain wrote in news: snipped-for-privacy@sympatico.ca:

When I first start it up and it's cold I can hit 60psi but at idle when it's hot (210 degrees or so) it's down around 8psi. Even at 50mph or so when it's hot it only hits about 16psi or so. Sound pretty bad?

Reply to
Shaggie

The 304's oil pump is part of the timing cover. Don't forget to prime it

-- I forgot and ended up priming it by squirting oil down the oil filter passage with a squirt can. It worked.

Reply to
Lee Ayrton

Moses Ludel says that oil pressure below 37psi @ 1600 rpm and below 13psi @ 600 rpm is outside the limits, based on his experience with the 304. YMMV.

Reply to
Lee Ayrton

While you may be able to get pressure back up with a new hi-volume pump, that's not likely the source of your problem. Oil pressure is most likely low because of excessive clearance in the crank and/or cam bearings. Higher volume of oil will compensate for the increased clearance, but you'd be much better off locating the problem and fixing that. Even with the restored oil pressure you are at great risk of spinning a bearing if they're worn to that degree. Catch it now and you can repair it in vehicle for the cost of the shells and gaskets. Wait until one spins and it's R & R engine, grind crank, resize rod (remove head to do that) etc. Pull the pan and pull a couple of rod caps and the main caps furthest from the pump. Look for obvious signs of wear, ie, the copper backing showing through the bearing surface. If it's not apparent get some plasti-gage and check the actual clearance. Cam bearings can't be checked easily, but are less likely to be the problem. I would only suspect them if the crank checked out okay. Steve

Reply to
Steve G

I will have to agree with Steve.

Even just putting a set of 'stock' for your engine main and connecting rod bearings back in will jump the pressure way back up. If you plastigauge it, you can get 0.001 or 0.002 over to make it tight again...

Mike

86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00 88 Cherokee 235 BFG AT's

Steve G wrote:

Reply to
Mike Romain

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