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88 4.0 rebuilt engine, blowing oil through cap


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Ok. Ive done everything I can to fix this. I rebuilt the engine, rings, piston heads, rod bearings, main bearings, seals, push rods, lifters, rockers, valve cover mods, oil fill cap mods, oil pump, vaccuum hoses, spark plugs, 

 

i drive this truck 5 miles….. its like weak. So i order from trevor waiting on new injectors. MY biggest problem is the 2-3 qts of oil blowing out the oil fill cap in just a 5 mile ride at roughly 45-50 mi an hour. Ive checked to see where its leaking from several times…. Its all from the cap. The ccv is not stopped up. I pull the hose and its sucking. 🤦🏻‍♀️😖. I had a friend do a compression test… he said everything was fine. Sooooooo, i will say the oil shoots 8ft literally from all the rockers. And I assume because of this its just hitting the hell outta that oil cap. Please help

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30 minutes ago, fiddlermj said:

Well, the gauge in it says 35-40….. but i think its higher than that

I'd agree that the oil pressure seems on the lower end from a fresh rebuild. Might want to check it with a mechanical gauge. Is it a geyser out off all of the rockers or just a few of them? 

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27 minutes ago, fiddlermj said:

It geysers out of all of them at 8 ft no joke

 

Goodness, that's probably what Old Faithful wants to be when it grows up. At least its all rust proofed. 

 

So somehow, it seems that the lifters are getting way too much oil or possibly that the lifters are diverting all of their oil up through the pushrods. I'm betting the first option though. 

 

Does it sound like it has a lifter tick? 

Being that it did it with the old oil pump too, I think we can safely rule that out from being the cause. 

 

I found this on how the oiling system in the 4.0 works:

Quote

From the FSM:
LUBRICATION SYSTEM
A gear—type positive displacement pump is
mounted at the underside of the block opposite the
No. 4 main bearing. The pump draws oil through the
screen and inlet tube from the sump at the rear of
the oil pan. The oil is driven between the drive and
idler gears and pump body, then forced through the
outlet to the block. An oil gallery in the block channels
the oil to the inlet side of the full flow oil filter.
After passing through the filter element, the oil
passes from the center outlet of the filter through an
oil gallery that channels the oil up to the main gallery
which extends the entire length of the block.
Galleries extend downward from the main oil gallery
to the upper shell of each main bearing. The
crankshaft is drilled internally to pass oil from the
main bearing journals (except number 4 main bearing
journal) to the connecting rod journals. Each connecting
rod bearing cap has a small squirt hole, oil
passes through the squirt hole and is thrown off as
the rod rotates. This oil throwoff lubricates the camshaft
lobes, distributor drive gear, cylinder walls, and
piston pins.
The hydraulic valve tappets receive oil directly
from the main oil gallery. Oil is provided to the camshaft
bearing through galleries. The front camshaft
bearing journal passes oil through the camshaft
sprocket to the timing chain. Oil drains back to the
oil pan under the number one main bearing cap.
The oil supply for the rocker arms and bridged
pivot assemblies is provided by the hydraulic valve
tappets which pass oil through hollow push rods to a
hole in the corresponding rocker arm. Oil from the
rocker arm lubricates the valve train components,
then passes down through the push rod guide holes
in the cylinder head past the valve tappet area, and
returns to the oil pan.

 

This has me thinking that possibly the main oil gallery is either somehow larger than it is supposed to be or that the other oil galleries coming off of the main gallery are partially blocked. No clue how that is possible though. 

 

How did the main and rod bearings look when you changed them?

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54 minutes ago, 89 MJ said:

Goodness, that's probably what Old Faithful wants to be when it grows up. At least its all rust proofed. 

 

So somehow, it seems that the lifters are getting way too much oil or possibly that the lifters are diverting all of their oil up through the pushrods. I'm betting the first option though. 

 

Does it sound like it has a lifter tick? 

Being that it did it with the old oil pump too, I think we can safely rule that out from being the cause. 

 

I found this on how the oiling system in the 4.0 works:

 

This has me thinking that possibly the main oil gallery is either somehow larger than it is supposed to be or that the other oil galleries coming off of the main gallery are partially blocked. No clue how that is possible though. 

 

How did the main and rod bearings look when you changed them?

I'm reading this right now give me a minute, but yes. it has the sound of ticking again. The old ones were fine just worn down to the brass look. When i went back in… AGAIN…. (Yes i changed everything twice 😖🙄 long story tracking ticking, which eventually lead me to rebuild cause i found rings on 6 broke) they were fine.

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Right, so, i installed all the bearings, i pushed in all sliding around…. This is gonna be dumb….cause I'm pretty sure i know but i second guessing myself these days—-but the holes, journals, line up themselves do they not? I know….. i laid them out in order and put new ones back in just like i pulled them out. One goes top the other bottom. One half has the hole… the other doesnt. 

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Oil blowing out of the fill cap would be due to crankcase pressurization.

 

Oil geysers from the pushrods would imply some serious blockage in the oil delivery system to the crankshaft, resulting in most of the oil going to the lifters, who, in turn, pump it up to the rocker gallery.

 

Did you clean out all the cross-drilled holes in the crank that feed from the mains to the rods?
 

Did you also make sure all the feed holes from the main oil galley that feeds the mains was clean?

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1 hour ago, 89 MJ said:

That would most likely be built into the oil pump

So. I dumped whole can (yea i know) seafoam in…. Ran it for bout 30 minutes. Drained oil…. Metal shavings. Guess there is something to the bearings

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