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Should Oil Be Spraying out of failed intake manifold/block interface by rear oil port

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Gossman78

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I shot video of oil leaking (spraying) out of interface of rear valley block interface.

If the seal was compromised and oil was leaking should it spray? I didn't think oil pressure was that high. It only sprays when accelerating or when load is on motor?

Is that rear oil port a 1/8 NPT or just 1/8 coarse?
 
sounds to me like a SBC, and it's 1/8NPT at least on the earlier blocks...and no, oil won't 'spray' from a failed intake to block seal---it'll run out, but not spray.
 
oh, and there's also another oil galley port just under the driver's side head in the back corner nearest the oil sender port. The gasket ALMOST covers it---don't ask how I know!!!:mad: (I'll just say this was many yrs ago and my first SBC build...):redneck:
 
Sorry Guys, it's a ZZ4 Crate motor circa 2000 but was just fired for the first time in Feb 2008. It's hard to make out but it's definitely spraying... On the video it's looks to be spraying from either A) the 1/8NPT brass plug or B) the intake block galley right next to the 1/8NPT.
 
So its gotta be a high pressure area thats causing the leak because in the valley there is only some splashing (very little) from the lifters.

Here is an idea but it will require some work and an old distributor. This will determine if it is indeed a high pressure problem. Get an old distributor and remove everything from the top and cut the housing above the clamp that retains it to the block. Hook up a drill to it and pressurize the system.
 
The oil pressure line is on the back of the block. I've popped the plastic line off before and had oil go everywhere.
 
crash said:
So its gotta be a high pressure area thats causing the leak because in the valley there is only some splashing (very little) from the lifters.

Here is an idea but it will require some work and an old distributor. This will determine if it is indeed a high pressure problem. Get an old distributor and remove everything from the top and cut the housing above the clamp that retains it to the block. Hook up a drill to it and pressurize the system.
Click to expand...
Crash,

I have one of these 'oiling' distributors I used prior to installation of the motor. I can totally pressurize the system with it. Question I have is why only does it leak under load and not as the motor first started and idles down the road? I mean isn't oil pump pressure somewhat independant of RPM? I mean isn't there a pressure switch that dumps anything over say 50 to 60 psi on the oil pump? It looks totally looks like it's coming from the lifter galley right behind the oil port. My plan was to replace the intake manifold gasket (again 3rd time) and clean out the oil port with a 1/8NPT tap...

The more I think about it I love the oiling distirbutor idea.....

THANKS CRASH
 
Gossman78 said:
Crash,

I have one of these 'oiling' distributors I used prior to installation of the motor. I can totally pressurize the system with it. Question I have is why only does it leak under load and not as the motor first started and idles down the road? I mean isn't oil pump pressure somewhat independant of RPM? I mean isn't there a pressure switch that dumps anything over say 50 to 60 psi on the oil pump? It looks totally looks like it's coming from the lifter galley right behind the oil port. My plan was to replace the intake manifold gasket (again 3rd time) and clean out the oil port with a 1/8NPT tap...

The more I think about it I love the oiling distirbutor idea.....

THANKS CRASH
Click to expand...

Yes, once oil pressure meets a certain amount it dumps via a relief valve on the side of the pump (and into the pan).

Only down side to the distributor idea is the lack of rpm against the pump meeting a high amount of pressure.

Another idea is to use air pressure, make an adapter at the oil filter(this is how we check oil pressure on the gen III motors) and pressurize the system.
 
One last question (I guess two) is that port a 1/8NPT and if I have an oil sending unit do I need the switch (relative to the ECM?).....
 
Gossman78 said:
One last question (I guess two) is that port a 1/8NPT and if I have an oil sending unit do I need the switch (relative to the ECM?).....
Click to expand...

They are either 1/8npt or 1/4npt. The gen III uses a non npt threaded hole for the sender (o-ring style).

It depends on what system you are running for needing any input into the ecm. The later year systems actually monitor the pressure and can set a code for it. You really don't need either.
 
Gossman78 said:
OH and to what pressure should I pressurize to? 50psi? What's safe for the gaskets....
Click to expand...

You can go higher than 50, just make sure the fill cap is off. Only way you can damage the gaskets is if you let the motor itself pressurize..
 
Yes directly above the top of the oil port or looking down on the back of the intake. It looks like its spraying from the manifold/block interface... but Im going to chase the 1/8NPT and replace the intake manifold both to try and address this, also going to look for some sort of a flaw in intake manifold or block in that area. Three times an RTV seal has failed and one of those times it was from GM Performance.
 
Do this. When you pull the intake, try using the distributor tool to pressurize the oil system. I just can't imagine oil coming from the sealant from between the block and intake.
 
Goose....can't believe I missed this post. Great videos by the way, is some way duct tape is always used to solve solutions.
 

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