killahxft_jeep
I have a slight problem.. started noticing it the other day.. oil pressure was running at about 50PSI on my mechanical guage.. then today after the jeep warms up it dropped to around 20PSI.. oil level dropped to the addoil line.. just got some new oil to add in.... but what could be causing this drop from 50PSI cold/warming up to 20PSI at idle.. faulty guage? it's a sunpro unit with the plastic clear line.
just so you know this is a AMC 360 out of 84 waggy, fully match balanced flywheel, with HEI, edelbrock intake, and edelbrock 600cfm 4barrel. headers... dunno if any of that is relavent to my oil issue.
runnamuck
sounds pretty normal to me. oil get thinner as it heats. also if its a fresh rebuild rings not seated yet would explain the missing quart and the blow-by would dilute the oil. or it could have so age to it and blowby doing the same as above. either way 20 psi warm should be fine as far as oil pressure.
Rhinolined360
bout 60 psi cold, 20psi hot. If its like 17or below while hot, i would worry.
killahxft_jeep
installed a new Faze electric oil pressure sender/guage... took it for a drive.. again same.. runs about 20PSI hot.. went for a bit longer drive.. look at the guage after driving say 6miles.. 5PSI?!?!?! wtf? quickly slow down & limp my way home.. get home, check oil level.. all good.. check for leaks at the sending unit.. not a drop... ordered up a oil pump kit from Napa & picked it up.. but have no clue how to install it other than removing the bolts from the oil pump unit on the timing cover.. and I don't know the conditions of the timing cover. not looking forward to pulling it & finding my timing cover is shot I need a new $300 piece to get my jeep running again..
tufcj
There's a large nut on the oil pump cover near the oil filter. Behind it is a strong spring and a plunger. This is a pressure relief, and could be stuck open. Make sure that the plunger moves freely for it's full range. Sludge/varnish can build up and make it stick. Carb cleaner can be used to clean it up.
To replace the pump, just remove the bolts on the cover. The old gears will slide out. Make sure the pump cover doesn't have any deep wear grooves in it. You can lap it flat with a piece of fine emery cloth on a perfectly flat surface, like a heavy glass plate. Once you install the new gears and cover, pump some oil back in thru the oil filter hole before restarting it. Install the gasket dry, no sealers are needed.
You could also get a mid-plate, or a new pump cover from the e-store here at Bulltear.
How many miles on your motor (total)? I've seen around 30-40% of the AMC V-8s with over 80K have bad cam bearings. That could cause your low oil pressure.
Bob
tufcj
killahxft_jeep
mileage unknown.. when I tore the oil pan off to asses it's age, i noticed that all the pistons seemed new & there were still hatchmarks in the bores. engine spun freely when i got it & was told by the guy I bought it from (was salvaged from a grand waggy).. told me it was taken from a DD.... when it first ran it produced plenty of pressure & I made sure to get the oil pump primed & ready to run before hand..
I have already ordered up the SS midplate from BJoffroad since the one from here was'nt avaliable. hopefully this will solve my problems.. I was wondering about that large bolt on the backside.. figured it had to do something with the pressure relief.
killahxft_jeep
oh and no matter how much I rev the engine the oil pressure never changes.. with either the mechanical, or electric guages..
woodfar51
Sounds like pressure relief to me also. Clean well and pack with vaseline before putting cover on. This will keep pump from dry start
killahxft_jeep
I cleaned it all out & put in the new pressure relief valve in with the new spring & primed withy oil & packed the gears with vasaline.. when it's 20* out vaseline becomes like a paste..
SuperCJ
AMCs have typically never been known for great oil pressure. You didn't mention the viscosity you were using. I run 20W-50 and my pressure runs @20PSI at idle, @50PSI at 2500.
killahxft_jeep
after the new timing cover & HRC cut gears I'm getting nearly 50PSI at idle & about 60-70PSI driving around. cold i run about 60PSI until the oil heats up.. I'm running 10w40.
