360 oiling trouble

Goose

Hi All, I'm Sure this is an old topic but .. My Trusty 360 is developing some oil pressure problems.. 60 psi cold 25 psi at operating temp at about 2500 rpm and close enough to 0 psi at idle to make my hair stand on end..but the peculiar thing is driving down the highway when you take your foot off the gas to slow down the oil pressure increases about 5-10 psi?? Also oh learned ones.. is it the timing cover itself that wears from the oil pump or is it the plate on the bottom ? Help ! Guide me.. I have come to the mountain seeking wisdom.. :lo1l: Thanks and Sorry if this is a stale topic..

Lifted79CJ7

Welcome aboard Goose! Try this page, should have lots of info for you. MC (jeepsr4ever) can also go into as much detail as you can stand about AMC's and oiling - he needs to get a hobby! 8) Anywho, hope this helps!

http://www.bulltear.com/forum/viewforum.php?f=25

Jack

pyagid

As well as the link that Lifted gave you... It sounds like your bearings may be worn. What you described is a characteristic of that. As the engine speed increases and Oil volume and pressure increse it forces worn bearings off the crank and gives an overall lower pressure. Hopefully someone else could chime in with a better solution, or symptom than me. -Paul

tufcj

Nearly every early (say late 70s and older) AMC engine with high mileage that I've torn down has had damaged cam bearings. It seems the factory AMC cam bearings were prone to flake apart (and usually the #3 or #4 bearing). My 74 engine in my CJ lost about 15-20 PSI across the RPM range when the bearing went bad. The bad news was that when the cam bearing broke down the metal particles went thru the engine, damaging the oil pump, main and rod bearings. I ended up doing a total rebuild, even though it only ran about 500 miles with low pressure. :smile:

jeepsr4ever

tufcj is like alot of us and have gone round and round with the oiling issues... Alot of concern initially would be what type of oil are you running and is your pan full...we really have to start with the basics here. Also what types of filters have you been using...some filters like fram are too fine and cause the oil filter bypass to open and let dirty oil into your engine. Have you ever overheated the engine? What is the mileage on the motor? In a good oil/ideal environment the cam bearings willbe the first to go..tufcj has experienced this as well (this would be without over revving or quick bursts of acceleration) main bearings can be starved very quicklyand when you revv the engine up and hold it at a high rpm do you hear what sounds like rattling or a diesel type sound fomr the bottom half of your motor? ...that would be mains or rod bearings. Alot of the time it is bearing wear but sometimes you get lucky and only have to replace your oil pump parts or pump itself

Goose

Thanks all, Well the ol 360 has so many miles on it and so many high rpm idiot shots that it's no surprise that I must rebuild it. 100,000 + miles and for a while this engine was in an early gremlin and raced regularly. I really appreciate the help..

Goose

Just a follow up now that I have the Engine apart. The mains are pretty much pure copper and the rods are getting that way.. So the prize winning advice was bearing wear (So far). I havent gotten to the cam bearings yet but will probably replace them out sheer fear.. Now for the big question. How can you tell if the oil pump cavity in the timing cover is worn out?? there is some slight scoring where the gears have ridden. and the bottom cover for the oil pump cavity has some wear in the same area ( I have a new one of these) but I need to know how to determine whether I need to order one of those snazzy new front covers or blow the money on other goodies!! Thanks again :idea:

jeepsr4ever

oyu install new gears and check clearances with a feeler guage. Your pump may or may not need to be replaced so dont buy one yet