Where’s all my oil going???

[stubble88]

New 3.4 engine
Very large oil cooler on front of car. (Added 5 qts here)
Original oil lines and thermostat
Original oil tank and hoses.
Completely dry when I started filling with oil
Turning over the motor to get the oil distributed.
I now have counted 19 quarts of oil!!!! Turn it over and it still wants more!
Oil level sender is new and working and after I turn the motor over it keeps emptying out the tank. Dipstick says the same thing. No oil.
I don’t see any oil on the spark plugs.
What is happening?

[Showdown]

You check the oil once the engine is warm and at idle, not cold and not with the gauge which can be notoriously inaccurate.

Drain some oil- like 10 quarts and run the car up to temp (180F) and then check the oil with the dipstick while the car is on level ground.


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[stubble88]

Right. But with a completely new and dry motor how much oil are we thinking I should start with. 10?

[stownsen914]

Yeah 19 is too many. A large front cooler will account for some, but even 5 sounds like too many for a cooler, even a big one. Sounds like your engine is ingesting oil but possibly not scavenging it properly. I'd guess you have way too much oil sitting in the bottom of your engine at the moment. 19 is enough that I'd be a little concerned to start it - it may spew a ton of oil out the case vent into wherever it's venting on your engine (airbox, or catch can), and make a big mess.

I'd want to take a look at the oil filter on your tank and see if any oil made it that far - that's the last stop in the scavenge system before dumping into the tank.

[stubble88]

I drained 16 qts. added 10 back in. Thanks

[stownsen914]

If the engine's been sitting with all that oil, there is a chance enough oil will migrate past the piston rings to create a hydro lock situation in your cylinders. This can damage the engine, even turning it over on the starter. You can check for this by turning it over with a wrench on the crank pulley, or putting it in gear with one side of the car jacked and the other on the ground (to block one wheel from turning) and turn the engine over while in 5th gear. If there's hydro lock it'll just stop at some point.

[stubble88]

I pulled 1 and 4 plugs. And turned it over. No oil. Stuck a camera down there too. Nothing. It was cranking freely.

[stownsen914]

Ok that's good. It's probably fine, but I'd still want to see oil at the filter before firing it up. Easy enough to check.

[stubble88]

Took the filter off and found evidence of oil. Wasn’t pouring out but it wouldn’t I’m guessing.

[stownsen914]

Ok that's good. I'm a bit anal and would want to see the oil circulating normally before firing it up. Maybe crank again and see if the level stabilizes in the tank now that it should have circulated everywhere. The concern would be if there is some blockage in your scavenge circuit like a rag left in an oil line (it happens) or a mis-routed oil line. Firing it up with either of those situations would end badly.

[Flat6pac]

During the build, the seal dropped off on the scavange side of the pump giving you limited scavange flow but dumping back into case.
Bruce
Just a thought on something I’ve seen

[stubble88]

Well I guess I won’t be firing it up today then. How much oil could still be in the filter after a couple cranks? Should it be just pouring out?
I’m not totally familiar with how all the oil flows around. Guess I need to research that some more. The oil I did drain looks like it collected all the assembly lube. Looked terrible.

[stownsen914]

Once oil has gotten everywhere by priming, it should equalize and level off in the tank. Usually this happens on startup, seeing as you identified a possible issue, personally I’d want to confirm normal system operation before starting it up.

A couple things you can do:
Confirm oil line routing (easy)
Check for blockages in the scavenge oil lines (rag, etc)
Crank it some more and see if the oil level normalizes in the tank

Have a look at a 911 oil system diagram, it’ll help visualize where the oil is supposed to go and could help in troubleshooting.

[stownsen914]

As for how much oil should be in the filter, eventually the filter should fill up. I’d have thought that by the time you got 19 quarts into your engine, the filter would be full, so that is suspicious.

[stubble88]

Drained oil again. 3 gallons came out or 12 qts

[stubble88]

Added 10 qts after draining the 12. Now level is staying full. Lots of oil in the filter. Maybe it takes a lot of cranking to get the oil everywhere?

[stubble88]

Weird. Now it’s keeping the level. Also seeing more oil pressure. Guess it takes a really long time for the oil to fill all the granny crannies?

[stownsen914]

Hmm, maybe it was nothing or just an air pocket somewhere in the system took a while to burp? It probably does take some time for all the oil to get around, especially for a larger front cooler.

If the level has stabilized in the tank, personally I'd fire it up and watch the oil level closely for a bit.

[stubble88]

On one of my fills. The oil was not entering the engine. The oil tank was completely full and I drained the engine in which there was barely any oil drained. At that point I drained the tank and remove the large lower rubber hose and found no blockages.
Air in the system something that can happen?

[stownsen914]

In normal operation, oil enters the engine from the tank via the oil pump. After draining the tank and the engine, and before you start the engine, oil will tend to sit in the tank and slowly percolate its way past the pump into the engine, over perhaps a couple days' time. Or if you crank it or start up the engine, it usually equalizes pretty quickly.

As for air pockets, I don't think it's a common issue on 911s, but it can happen especially on the suction side of a pump.

Just to ask again, how sure are you that there wasn't a rag, paper towel, etc in one of the oil lines or elsewhere in the oil system. People often plug open oil lines when things are apart for maintenance (I do), and t's easy enough to forget one when reassembling everything. Part of me wonders if one was blocking something and causing your issue, and finally passed.