95 F150 5.0 - 296K rebuild no/low oil pressure
05-14-2015, 08:00 PM
#1
95 F150 5.0 - 296K rebuild no/low oil pressure
Sorry for the lengthy post (I'm sitting here drinking beer and crying over the keyboard). Been working on this truck all winter, started at the front rebuilt the motor, tranny (with "jerry" mod), and new bearings in the 8.8/axles. Did all the work myself I'm into this about $2000 in parts.
Finally got around to starting her up, no OP, so I hooked up a guage, 5psi at 1500rpm. Put the priming tool on the oil pump drive shaft (i feel resistance when turning the shaft by hand, so I believe I have it seated in the pump), corded drill doesn't turn it fast enough to move the pressure gauge (turning pump counter-clockwise). Thought I'd bleed the line to the gauge, I took the gauge all the way off the line while it was running and got a very low flow (I'd characterize as a strong trickle).
New oil pump (screen and tube also) installed with rebuild.
Also as part of the rebuild I replaced the heads with some junkyard replacements (the originals had cracks across/between four valves (seats)). I blasted and cleaned the heads, I did have to chase all of the bolts holes - I'm wondering if I could have a clogged passage somewhere (thinking that a really low probability).
When I polished the crank, they mic'd at .004 -.006 if my memory is correct (thought I read somewhere that was okay).
I'm reading some guys suggesting worn bearings in other threads for low OP, I'm wondering if I've done something wrong there.
I installed new cam bearings, I've check the oil passage on those about a hundred times I know they are correctly aligned.
I've got (some) oil moving around the engine, I pulled the new oil filter it is full, and I have to confess I forgot one of the plugs on the back of the block and had to pull the tranny to install that...only found it when oil was dripping down the flexplate/spacer plate; its just very low flow. (originally thought that might be the reason for low OP)
I certainly don't have a good depth of knowledge on how the oil flows through and round the engine - how does a loose main bearing cause this?
Anyone ever have a similar problem, I've likely boogered something up, I'd like if someone did a similar mistake and point me the right direction before I have pull the motor and start over (wife will love that...).
(while I'm waiting for any thoughts I have go out find the tools that went flying when I drop kicked that toolbox...)
Finally got around to starting her up, no OP, so I hooked up a guage, 5psi at 1500rpm. Put the priming tool on the oil pump drive shaft (i feel resistance when turning the shaft by hand, so I believe I have it seated in the pump), corded drill doesn't turn it fast enough to move the pressure gauge (turning pump counter-clockwise). Thought I'd bleed the line to the gauge, I took the gauge all the way off the line while it was running and got a very low flow (I'd characterize as a strong trickle).
New oil pump (screen and tube also) installed with rebuild.
Also as part of the rebuild I replaced the heads with some junkyard replacements (the originals had cracks across/between four valves (seats)). I blasted and cleaned the heads, I did have to chase all of the bolts holes - I'm wondering if I could have a clogged passage somewhere (thinking that a really low probability).
When I polished the crank, they mic'd at .004 -.006 if my memory is correct (thought I read somewhere that was okay).
I'm reading some guys suggesting worn bearings in other threads for low OP, I'm wondering if I've done something wrong there.
I installed new cam bearings, I've check the oil passage on those about a hundred times I know they are correctly aligned.
I've got (some) oil moving around the engine, I pulled the new oil filter it is full, and I have to confess I forgot one of the plugs on the back of the block and had to pull the tranny to install that...only found it when oil was dripping down the flexplate/spacer plate; its just very low flow. (originally thought that might be the reason for low OP)
I certainly don't have a good depth of knowledge on how the oil flows through and round the engine - how does a loose main bearing cause this?
Anyone ever have a similar problem, I've likely boogered something up, I'd like if someone did a similar mistake and point me the right direction before I have pull the motor and start over (wife will love that...).
(while I'm waiting for any thoughts I have go out find the tools that went flying when I drop kicked that toolbox...)
Last edited by ytudrepus; 05-14-2015 at 08:08 PM. Reason: typos
10-15-2016, 12:54 AM
#2
Could be a bearing problem? On a high miles engine with low oil pressure, thats the first place to look. Can you pull the oil pan with the engine installed?
can roll 1 bearing out at a time. But on an engine stand is a lot easier.
I feel for you. But take a breath, you did all that work so you can fix this.
can roll 1 bearing out at a time. But on an engine stand is a lot easier.
I feel for you. But take a breath, you did all that work so you can fix this.
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ytudrepus (10-15-2016)
10-15-2016, 06:28 AM
#3
Sorry I should have closed this months ago.
Ended up I overlooked an oil plug (actually didn't know it was there, the machine shop pulled when they cleaned it).
I took some investigating, but there is an oil plug (looks like mini freeze plug) under the intake manifold on the backside of the engine.
I did have to walk away for a couple weeks (didn't feel like tearing it apart after putting it all together)...
Thanks for responding.
Ended up I overlooked an oil plug (actually didn't know it was there, the machine shop pulled when they cleaned it).
I took some investigating, but there is an oil plug (looks like mini freeze plug) under the intake manifold on the backside of the engine.
I did have to walk away for a couple weeks (didn't feel like tearing it apart after putting it all together)...
Thanks for responding.
