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**DONOTDELETE** 01-03-2002 10:47 PM

High oil pressure on CJ8???
Guys, good bud just had his 258 rebuilt in his scrambler. Now whenever it runs, say around 45 or 50 or whatever, the oil pressure gauge is reading extremely high, almost all the way to the right at 80. What causes really high oil pressure, and what can it hurt?? Also, what should an engine of this size normally run while running and idling??? Thanks guys, Mike. PS Going to look at CJ this sat, will report back on how she is??

85 Bronco XLT, 351W H.O.
32" Big O At's on stock susp.
True dual flomaster 40 series mufflers.
CJ trail rig on the way!!
"When in doubt, HAMMER DOWN SON!"

kansasjeeper 01-04-2002 06:22 PM

Re: High oil pressure on CJ8???
Wierd, I always understood the 258 to have lower oil pressures. My Scrambler 258 rebuild w/75K runs around 20. The main bearings could be too tight, there could be a high-flow oil pump in there, or blocked oil passage somewhere. Of couse, I would go the cheap route first and hook a mechanical oil pressure guage with the plastic line in place of the electric oil pressure sender and confirm the high oil pressure. Then if it is that high, go talk to the rebuilder and see what he put inside the engine. I've never heard of a 258 having that high of oil pressure. Also, make sure there is regular oil in there and not gear lube.

dschwab9 01-04-2002 06:30 PM

Re: High oil pressure on CJ8???
Could be a plugged passage somewhere, bearings too tight, or posssibly a bad guage. Might won't to see what kind of reading you get with a mechanical guage. Also make sure he's running 5-30 in it and not 20-50 or something.

-Derek Schwab
'97 Sidekick Sport
'83 CJ-7

bluseman2a 01-04-2002 09:46 PM

Re: High oil pressure on CJ8???
I had the same problem on mine when I first rebuilt it. The FIRST thing to check before you get all crazy is the Oil filter nipple.

1) Take the filter off.

2) There is a large nut holding a retainer plate on (mine was 22mm, but that changes from year to year). Remove the nut and BE CAREFUL.

3) When you pull the retainer plate off, there will be a spring, and a piece of waffle-board/plastic that come out.

4) Make sure that the setup is assembled properly. Sometimes they will get the plastic piece cockeyed or not put one in there at all.

5) I BELIEVE (don't hold me to it, and SOMEBODY double-check me with the FSM, please) the spring/waffleboard should be assembled in the following manner: Waffboard in first into the block, then the spring, then the plate.

If anything is wrong with this assembly, then it could give you the symptoms you described.

Also of note, if he traded his core in on a rebuild, then there is a possibility they have traded the SAE nipple for the oil filter for a METRIC nipple. The symtom exhibited here is that the filter will screw on and tighten as you would expect, but will eventually be blown off the block (making a HELL of a mess).

'83 CJ-7 nothing original but the tub and axle tubes

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