[Vid]

Hi All,
New build with a curious oil pressure problem. I’m already in the process of removing the motor to tear it back down for a full inspection, no way around that… but here’s what’s happening:

I’m somewhat familiar with Pontiac’s “series” style oil pathway and have some vague ideas about what might be the issue. The left (driver) side oil galley is showing some oil pressure, but the right side is not. When I pulled the two forward lifters and spun the oil pump with a 500rpm drill, driver’s side lifter bores flow oil, but the passenger side does not. By “some” oil pressure I mean it’s not spraying an oily mess out of the bore, but there is some flow there similar to a slow pour out of a quart bottle I guess. Remember it’s only a 500 rpm drill doing the spinning but I think that is similar to 1000 rpm from the crank so it should be adequate.

Let me cover the few things I do know.
1. Boroscope in the oil pan shows the oil pump drive shaft spinning the pump just fine. Oil pickup still attached etc. Oil pump is a high pressure unit from Summit. I did prime and “bucket” test it prior to installation and seemed fine.
2. Main bearing clearance was right around .0025 and rod bearing clearance .0015 (plastigauge).
3. On initial start up, oil pressure gauge showed 60 psi +/-. Gauge needle very soon started fluttering pretty wildly and then showed something between only 3-5lbs so I shut it down immediately. Running Lucas 30w break-in oil plus a 4oz bottle ZDDP of additive mixed in.
4. Haven’t removed the timing cover yet to inspect the galley plugs. The plugs were staked by my local machine shop. I wish I tapped them in hindsight.
5. These are proper Pontiac hydraulic lifters (Crower Cam Saver) and not Chevy lifters with the oil band too low. Lifter bores don’t seem to have excessive clearance from what I can tell but I didn’t measure. Surely the “cam saver” groove down the side of the lifter wouldn’t cause an issue like this?
6. I know about the hidden galley plug by the diz gear and it’s in place, so it’s not that.

I tried posting a video link below, hopefully it works. Meanwhile there’s a photo with the two lifters out.

Once I get the motor out, obviously I’ll know a lot more. Just curious what the “hive mind” thinks this problem could be. This is my 4th Pontiac V8 motor build and my 9th motor build overall. Not an expert but not completely green either. Super bummed that this one was not successful! Thanks in advance for your consideration.


https://share.icloud.com/photos/0800...xLTGJ2Ii7TJQ1A


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[steve25]

After what you have listed as being checked there’s only 3 possibilities.
1) oil galley plug in the face of the block.

2) bad pump.

3) oil filter internally collapsed and blocking flow.

[Gach]

I would pull timing cover first before you pull motor out and check oil Galley plug in front of the block if they we never tapped and put in threaded plugs then that would definitely be my next move. Just seen to many of those freeze plug type blow out or just leak like crazy. Just good insurance

[Vid]

Originally Posted by steve25

After what you have listed as being checked there’s only 3 possibilities.
1) oil galley plug in the face of the block.

2) bad pump.

3) oil filter internally collapsed and blocking flow.

Thanks Steve. It’s actually down to two because not only did I change the filter, I changed the filter boss as well. Same outcome unfortunately. Good news is that the oil filter element was clean when I inspected it. I’m more than a little worried about the hft cam lobes though just because even under ideal conditions we all know how problematic they can be. I’m worried about that right side.

I have a new cam and lifters and a new 80 lb oil pump from Butler on my bench ready to go.


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[Vid]

Originally Posted by steve25

After what you have listed as being checked there’s only 3 possibilities.
1) oil galley plug in the face of the block.

2) bad pump.

3) oil filter internally collapsed and blocking flow.

Thanks Steve. It’s actually down to two because not only did I change the filter, I changed the filter boss as well. Same outcome unfortunately. Good news is that the oil filter element was clean when I inspected it. I’m more than a little worried about the hft cam lobes though just because even under ideal conditions we all know how problematic they can be. I’m worried about that right side.

I have a new cam and lifters and a new 80 lb oil pump from Butler on my bench ready to go.


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[johnta1]

Change cam bearings?

Bearing covering hole that goes to passenger side?

Or agree with Gach on galley plug came out.
(since you said the rear plug can be seen)

[Vid]

Originally Posted by Gach

I would pull timing cover first before you pull motor out and check oil Galley plug in front of the block if they we never tapped and put in threaded plugs then that would definitely be my next move. Just seen to many of those freeze plug type blow out or just leak like crazy. Just good insurance

My thoughts as well. That’s my last ditch attempt before yanking it out. Wouldn’t I love to see a plug blown out instead of having to replace the pump!


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[TedRamAirII]

You should be able to pull the fuel pump out and look at the front of the block see if there's a huge oil leak at the front of the block.

[Vid]

Originally Posted by johnta1

Change cam bearings?

Bearing covering hole that goes to passenger side?

Or agree with Gach on galley plug came out.
(since you said the rear plug can be seen)

All I can say is that I did inspect the cam bearings for fit and alignment before I installed the cam. Seemed to be lined up just fine. Cam spun smoothly with no tight spots or other issues. Plenty of assembly lube on the journals. But the thought about cam bearings had crossed my mind because of the oil pathway.


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[Vid]

Originally Posted by TedRamAirII

You should be able to pull the fuel pump out and look at the front of the block see if there's a huge oil leak at the front of the block.

Now that’s a great idea! I could even get in there and look around with the boroscope if it’s not gushing. Thanks for that suggestion Ted!


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[Gach]

Not saying this is the cause, but did one for a friend, when I took out galley plug in front I found it plugged solid Evidently when they hot tank the block, they neglected to clean out that side.

[Jay S]

If you want to narrow it down some you can prime the oil pump with the oil filter off. (Have a catch pan ready!)

If if doesn’t flow out the filter much oil pump probably got a chunk of something stuck in the relief valve.

If it flows like crazy a galley plug got pushed out, or was forgotten.

[steve25]

If it turns out to be a plug that popped out then when you drive in a new one don't go to the other extreme and drive it in so deep that it partially blocks off the oil passage running up thru that front bulk head.

I have seen that before also.

[Holeshot71]

Is it possible those studs in the lifter valley bottomed out into the cam bearings?

[steve25]

If so that might pinch off the Cam bearings but. Not effect oil flow in the least.

[Holeshot71]

Originally Posted by steve25

If so that might pinch off the Cam bearings but. Not effect oil flow in the least.

It would certainly help the bearings move or spin.

[Tim Corcoran]

If there is a piece of crud stuck under the relief ball in the oil pump it would still flow some oil but not enough, this could be the cause or your dilemma. If you put all the lifters back in and you turn the oil pump at 500 RPM what does the oil pressure read?

[Vid]

Originally Posted by Tim Corcoran

If there is a piece of crud stuck under the relief ball in the oil pump it would still flow some oil but not enough, this could be the cause or your dilemma. If you put all the lifters back in and you turn the oil pump at 500 RPM what does the oil pressure read?

Between 3-5 lbs, probably closer to 3…


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[Vid]

Originally Posted by Holeshot71

It would certainly help the bearings move or spin.

I think there’s clearance but I’ll check it out, you never know.


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[blueghoast]

What probly happen'd is someone left the right rear galley plug out.
There is a pressed in one on the outside of the block and a screw in
one inside behind that. Check there. Ask me how I know. Good Luck.

GT