Oil pressure
 

Just got thru rebuilding a 318 mopar magnum engine, At running temp the engine will not hold oil pressure @idle running temp it will fall to 0 psi, tried everything i know,everything in engine is new, tried three oil pumps, two were high volume, Have removed main cap's bearings in correctly, removed cam bearings in correctly, replaced pickup twice, Loosing the rest of my hair on this one :? :?



''JUST MY TWO CENT'S WORTH''

Well I would say take off the Fram oil filter and it might come back. j/k

Have you checked the shaft that drives the oil pump?

Are you sure the gauge is accurate?

Yes have a electric one that hooks up to engine test machine, shows engine temp, scope all cylinder's for power balance, etc, + manual gauge, both drops to 0 psi @200 degrees @ idle, no fram filter, mopar filter. Thought about that filter collapse Changed it but no help, Checked drive shaft good condition,start getting lifter tap shut her down quick, Added thing talked to owner about a hour ago he told me it was doing this same thing before i got to it. he was running it like this.


''JUST MY TWO CENT'S WORTH''

MARK , It sounds like an oil passage plug has backed out somewhere , not sure how a mopar is made , but on some ford blocks there is a small freeze plug in lifter valley in an oil galley , had one come out and lose pressure , after I wrestled with oil pan to change pump , I removed intake and found the plug out ( lucked out ) , does mopar have any plugs behind timing gears??? if it was like that before then it has to be an open somehere since you changed everything else ...

pesiol sludged up that fast huh? j/k had a 350 lost oil pressure one day never came back at least what 2 gauges said ran that way for 6 months brfore had a chance to tear down no damage and never figured it out just damn lucky hows the pick up tube? just idea but maybe a small crack and expands when warmed up

No mopar doesn't have those plug's, It has two holes there so oil can run out on timing chain then the oil goes down the front cover to pan.Changed pickup tube twice.

lets assume that it IS pumping since you changed everything , it is not making it to the lifters , so there is an opening between the pump and the lifter passages somewhere,,either that or some reason it just not pumping , can you spin the pump with dist out and see if its pumping , does mopar have the sealing rings around dist shaft where it passes thru oil galley????

Ok the magnum engine is setup just like chevy engine oil's thru push rod's to rockers, does good untill engine get's running temp then you can watch it just trickle away. Running 10w30 oil. Now this engine is not in the truck it is on a break in stand with all the gauges, tach,raditor, etc.

lifter bore clearance not excessive?

you got me!!!!!!!! since it was doing it before rebuild , I still say its in the block such as a crack opening up under heat or something , if its pumping then its leaking somewhere....you didn't say about distributer seals on shaft???

I am thinking a oil passage is cracked somewhere in the block, This job is now costing me money, Lossing my A$$ on this one. No lifter bore's checked out great engine had 134,000 before rebuild.



''JUST MY TWO CENT'S WORTH''

i would lean towards that too :cry:

The oil pump bolts up just like chevy, to rear main cap, same type of oiler shaft etc, Just don't have any other answer.

for what its worth,ran into a chevy that start to leak out the rear of the block at about 7 years old through porosity in the casting at rear of block. anythings possible.

Hey i am open to any answer i am going to print these suggestions and try all tomorrow, at this point i want rid of this thing driving my nut's and right now that is a short drive :lol: :lol: this $2000.00 rebuild is heading to $3500.00 if i have to buy a new block.

if your luck is like mine, they could make 100000 of something with 1 defective & damn if that one doesn't end up being the one I get stuck with :roll:

I think it would be cheaper to buy the truck :!: :!:

you shouldn't be eating the cost of the block, the labor is bad enough

Do the rockers ride on a shaft like the B blocks? If so, is the shaft gunked up? After the engine cools, does the oil pressure return? The base where the pump bolts on may be uneven or flexing when the block warms up, that would allow the oil to spray in the pan rather than thru the system. Grasping at straws on this one.

No the rocker setup is just like chevy's each one has a bolt to hold to head, oil's thru pushrods like chevy's, now that is one thing i haven't looked at, the mounting of pump to rear main might be something there oil spraying back to pan Hmmmm, Well, Well

I would say fla1976 may be on to somethink there :idea:

too bad they didnt make a see through pan to see if that was the issue of course guy could take an old pan cut a window in it an use peratex and rivits with a peice of plexi glass to make one

Now that is a idea, could make one pretty quick, plexiglass with some sealer.

i posted my problem exactly like this, with a sbc, that turned out to be a oil galley plug with a minor leak, but when the oils warm it squirted out which lost all oil pressure

X2, have you checked to see if the rear main cap is cracked. I'm not a mopar person although i've owned and rebiult a couple of them. I don't see a solution without pulling the bottom end down and looking at everything. If the lifters are banging at idle then i don't think it's the gage.

JMO

Zip.

Does the engine have galley plugs behind the timing cover like the small block Chevy. If it does, I would agree with KWKRACING and MANIAC that it may be the problem. There is no obvious leak that is visible, but the oil is not going to go to the top end.

http://www.youtube.com/watch?v=Jz1Z-AS5H1M kw's oil leak video

don't know much about mopar,s, but could there be a problem with gear attchment to the secondery pump shaft? just a thought, good luck.

check out this page http://www.forabodiesonly.com/mopar/...ad.php?p=68234 they are talking about loose oil galley plugs causing low pressure.. read the whole thread , they talk about 2 different ones...hope this helps

here is were all the oil plugs go in a small block mopar. 2 behind top timing gear some times coverd by cam retaner plate, or cup plugs. rear of the lifter galleys. one is on the outside right bank. left side is on the inside can be seen through the distributor hole with a mirror. like olds, pontaic v8. plug under oil filter plate 3/8 npt. these last two have ben left out many times there is a seperation plug that goes in the vertical passage from the oil pump, this plug directs oil to the filter, sometimes this plug cannot be removed. this is the same as sb chev.this plug is left out all the time on sb chev. i think all the new sb mopars are the same as old style far as oiling goes. i did see one sb style v6 that was cracked from main bearing to the cam stickboy331

good info ,alright , mark , get busy looking :D

:idea: Drop the pan, take off the oil pump, make an adapter and put an air hose to it with a leak down tester, it may be messy but once the oil is cleared out you see where all the air is going out.

Zip.

Thanks guys let's see what happens.

Hey Mark , any luck on the 318 yet?

Nothing yet still digging !!

Well folks found problem, At the rear of lifter galley right rear, has a I call it a small casting hole, Used air and heard it hissing, hard to find but felt air coming out, used mirror and oil sprayed on mirror, Thank all you guy's for your input, now to replace the block, owner agreed to pay for block and i get to build it, Again thank's :!: :!: :!:


''JUST MY TWO CENT'S WORTH''

can you make a sleeve or plug to slide in to the oil galley ,block off the galley before the leak? if the leak is in the right spot :idea:

No not where it is at, Double D I had it on a engine run stand thank god, I always run them before installing them cut's down on headaches :lol: :lol:



''JUST MY TWO CENT'S WORTH''