Rebuilt Engine, Super Low Oil Pressure :(

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CaseyW

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I recently had my slant six machined and completely rebuilt. I did the rebuilding, a shop did the machining. It was my first rebuild and I made a lot of mistakes along the way, but I got her running and thought everything was going good until the oil light came on :(
I don't remember if the oil light came on initially when I started it, but it wasn't long after that it would flicker on and off.
Whats going on:
-No Oil to rockers
-Oil light flickers on and off
-Installed electric oil gauge, 7-10 Psi
-I pulled the filter and ran her for 5 seconds (maybe a bad idea) and she spilled about a half quart of oil, so the pump is working, but it wasn't blasting out (should it?). It was pulsing out maybe 1/4" high stream.
- Oil Pump is new

Any suggestions? How do I check to see if oil is getting to the journals? I really don't want to pull the engine back out but that might be what it comes down to. Thanks
 
did you remember to install the oil galley plugs on the front of the block?

also do you have the shaft for the rockers on the right way?
 
Did you prime the engine before you started it?
 
805moparkid said:
cant with a slant other than having no plugs and spining it over...
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Assemble the engine cept the timing chain and rockers. Torque cam gear down. Spin camshaft with air ratchet.

Next.

I thought you were a slant guy.
 
RustyRatRod said:
Assemble the engine cept the timing chain and rockers. Torque cam gear down. Spin camshaft with air ratchet.

Next.

I thought you were a slant guy.
Click to expand...


haha thats awesome... just use alot of lube on assembly and spin it with no plugs and its primes quick! alot less work to.
 
How you figure? You gotta assemble it. Why not prime it first? Only takes a few minutes. At least that way nothing starts dry.
 
805moparkid said:
did you remember to install the oil galley plugs on the front of the block?

also do you have the shaft for the rockers on the right way?
Click to expand...

RustyRatRod said:
Did you prime the engine before you started it?
Click to expand...

Hmmm. I am thinking the machine shop installed the oil galley plugs. How many are there? Are they housed underneath the timing chain cover? I could call them and ask.

Rocker shaft is correct orientation, little notched part is at the front of the engine facing up.

should the oil be blasting out of the pump, or is that mild surging i described ok?
 
GPM normally, and a good solid stream.
As in if you started it and walked around to see it should have made a huge multi quart puddle.
Do you remember tightening the oil pump down?
Or happen to leave a rag in it?

It happens.
 
TrailBeast said:
GPM normally, and a good solid stream.
As in if you started it and walked around to see it should have made a huge multi quart puddle.
Do you remember tightening the oil pump down?
Or happen to leave a rag in it?

It happens.
Click to expand...

Damn...

I torqued it to spec. The pump is brand new. Pretty sure I didn't leave a rag in it. Unless there are other suggestions, looks like I need to pull the engine and check the pickup tube and oil pump...
 
Now are you sure you have the right pickup tube ? and did you check that it was not resting on the pan ? silly putty works good for that lol
 
Possible crack in pick up tube, sucking air? Also check pressure bypass valve in pump, might be stuck open, or even missing.
 
Had this happen in the 1980's. Just rebuilt, installed, started and had good pressure, drove home, parked and started to go to the store, had maybe 30 miles on it and pressure dropped to 7 psi. Oil pump was bad. Something about the pressure check spring stuck. Changed the pump, in the car, and was good to go thru 3 different cars and is still waiting on another.
 
TrailBeast said:
GPM normally, and a good solid stream.
As in if you started it and walked around to see it should have made a huge multi quart puddle.
Do you remember tightening the oil pump down?
Or happen to leave a rag in it?

It happens.
Click to expand...

i assumed he was just cranking so there wouldn't be much.

and i totally forgot about the pressure spring! could be stuck or missing.

as to your question there is a NPT plug front and read for the main oil galley.
 
Did you plasti-gauge the bearings? If they are too tight, well, oil is gonna have a hard time flowing to say the least.
 
I always take apart my pumps before putting them on. Every one has had machining shavings in them. Just an idea, it could be the problem?
 
mwls73duster360 said:
I always take apart my pumps before putting them on. Every one has had machining shavings in them. Just an idea, it could be the problem?
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now that you say that it got me thinking... when they returned you the motor and or parts what was the deal? you assemble? was it assembled? I ask because if your assembling it you need to do a final clean on the block and parts as well as gauge everything.
 
Use a manuel oil gauge and retest it.... If it's still low...Your pulling it to find out what happened...
Just My 2 cents
 
Dart_Doctor said:
Now are you sure you have the right pickup tube ? and did you check that it was not resting on the pan ? silly putty works good for that lol
Click to expand...

I used the one that was in it before the rebuild, and it had good oil pressure. I didn't check the clearance, but I do remember it didn't thread all the way back in, but stopped turning so I assumed it was where it should be.

Charrlie_S said:
Possible crack in pick up tube, sucking air? Also check pressure bypass valve in pump, might be stuck open, or even missing.
Click to expand...

I will check, crossing my fingers its as simple as that.

PoisonDart74 said:
Did you plasti-gauge the bearings? If they are too tight, well, oil is gonna have a hard time flowing to say the least.
Click to expand...

Did not plasti-guage. Didn't think it was necessary. Is that standard or overkill?

dano said:
When you installed the gauge, did you use a new sending unit?
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No, but I replaced the sending unit with an electric gauge to make sure it wasn't the sending unit, and it confirmed the low oil pressure.

mwls73duster360 said:
I always take apart my pumps before putting them on. Every one has had machining shavings in them. Just an idea, it could be the problem?
Click to expand...

Another possibility I will check into. I didn't dissassemble it.

805moparkid said:
now that you say that it got me thinking... when they returned you the motor and or parts what was the deal? you assemble? was it assembled? I ask because if your assembling it you need to do a final clean on the block and parts as well as gauge everything.
Click to expand...


I assembled. I did a wipe down and blasted it with compressed air, but I didn't clean the new pump I put on.

If shavings were to accumulate somewhere, is there a spot where they would generally accumulate to create blockage?
 
it will do the same thing if your clearances are too loose. plasti gauge should not be used to replace actual measurements, but it will give you a good idea of whats going on.
 
73AbodEE said:
it will do the same thing if your clearances are too loose. plasti gauge should not be used to replace actual measurements, but it will give you a good idea of whats going on.
Click to expand...

Hmm, the machine shop sent the crank out to be turned, and ordered all the parts, so I assumed everything would fit appropriately.
 
well add that to the live and learn column... you NEVER assume anything when building a motor... i really think you need to start over as when you tell them your assembling it yourself, they dont clean it.

where in CA are you? in about a month i'll be driving thru and maybe can help for a bit
 
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