oil pressure, why dont i have it

[fastranger347]

new 363 shortblock to replace my old 347, melling select hv oil pump, .002 on the rods and mains, with 10-30 oil i have 50 at idle and 65 running at speed, but after the oil gets up to temp it drops to 10 at idle and 30 at speed, since it is in a ranger i i by passed the oil filter and the oil coolerand with no filtration and cooler it only picked up 5 lbs, i put restrictors back on my turbos where i had none before and it dint changet the pressure....................... so when the oil/engine is cold pressre is great but then the engine is warm,not even hot, oil pressure dissapears, im ready to torch the engine so whatever you can tell me ide appreciate it, all the oil plugs are in the top,front,and back of the engine.

[mnm99]

Sounds like bearing clearances to me. When the oil gets thin there is more clearance, thus lowering your pressure. What oil are you using? Try to find a good oil that doesn't break down so much when heated up. I used to use a oil that didn't brake down so much, but forgout the name. Sorry. I think it was like a 20w50 oil. 10w30 gets real thin.

[fastranger347]

origionaly had .003 on the mains and i put a one under in it to tighten it up, and ive tried10-30, rotella 15-40, and mobile one 15-50 with very little change in pressure, and all these pressure issues are with me riving it in the driveway, barely building any heat, whe n i take it on the road the pressure goes to almost zero when i come to a stop so im afraid to drive it any farther, how tight should my bearings be, my 347 shortblock i had at .002 on the rod and mains with a melling select oil pump with the same oil filter/cooler setup and i i always had 40-60 psi all i did was swap shortblocks and  i cant get an pressure, its a dart block, eagle crank, eagle rods, je pistons, my rod side cleareance is .018, i dont know what to do.......................................................

[Bellman Jeff]

Do you have a hydraulic cam ?? If so, when the pressure drops way down like that.. Do the lifters start clacking.. If not, try changing your gauge.. Your oil pressure is probably good..

[fastranger347]

yes,lifters are hyd, and they do get noisy, the only thing i know to do is to tighten up the rod bearing clearance and put in another pump...

[10secgoal]

Cut the filter open and look for carnage before you do anything else. That'll tell you if need to pull it out or not. But right now if the bearings are fucked, hard parts are next.

[boost21]

Sounds like the bearings. My car did the same thing before the motor took a dump

[fastranger347]

i have coated bearings and a truefilter, aluminum filter witha stainless screen element, ive pulled it apart severalt imes and there is no debris..

[blacksaleen95]

electro or mech op gauge?

[green notch]

My 363  gets about 60 cold and drop down to 25-30 hot, what about cam bearings? I'm sure there new but?

[bgjohnson]

My 408 with HV pump gets 55-60psi when cold all the time. Then drops to 20-25psi at hot idle and 50psi at cruise.

If it gets super hot and it's warm out, pressure almost gets down to 15psi.

[PEARL MUSSIN]

Mine (357)  does the same thing, 50-65 idle cold and warm 25-30 idle , Super HOT 20 idle.  It been like this for 3years, I put a Melling select pump in it New rod/main bearings, same thing...  I tried all kinds of oil as well, only thing that seemed to work was a thing of lucas oil treatment, that shit is as thick as molasses.  I dont worry about it anymore...


Jeremy

[PrecisionTurboMustang]

Best thread title ever.

[bgjohnson]

I'm not too worried about it. If nothing knocks, or ticks when the idle drops, it still has enough pressure for everything to be lubed properly and still has a protective film.

Now if hot cruise got to 25-30psi, I'd get a little worried.

[Red91StangCT]

I may be way out of my league here, but who built the block??  Reason I ask is that I think there are supposed to be some oil plugs and/or restrictors installed in the block.  Were those put back in the block after rebuilding?

[fastranger347]

new dart block, im gonna change the oil to some rotella t and put one container of lucas in it, i really dont like to have an oil pressure below 30 at idle and ide like a minimum of 50 at cruise, and yes all the plugs are in the block...

[Bellman Jeff]

Make sure your pickup tube is well sealed to the pump..