oil dripping out exhaust system
12-12-2018, 11:42 AM
#1
Instructor
Thread Starter
oil dripping out exhaust system
Somehow I have screwed up but am not sure exactly where. Have installed a new cam and oil pump and in the process of the install of the oil pump slide it over shim stock on the pan gasket, did not undue the pan bolts, on reassembly put the pump on like you would an LS3 in installed the base first slide over shim stock so I would not damage the pan gasket, the pump bolts have black plastic injected into the over sized pump holes so there is no way to move the pump centring on the crank it only goes in one place unlike say an LS3 pump where you use shim stock to centre on the crank, reinstalled the gears as they came out as I marked each one on disassembly. Have started the engine run it briefly, have oil pressure at idle 50psi-70psi but oil level was probably over filled by me as the engine sat a couple of months waiting on my heads to be done and I believe the dry sump tank drained down into the engine. After running drained all the oil and only got 8l out yet think I put by mistake 12-13l in. I assume the pan gasket is leaking so the pump does not scavenge properly but how is the oil getting into the exhaust system, also the plugs are all oil fowled. Just about to start disassembly any ideas as to what I screwed up.
Last edited by G8Pumpkin; 12-12-2018 at 08:58 PM.
12-12-2018, 12:47 PM
#2
Le Mans Master
Somehow I have screwed up but am not sure exactly where. Have installed a new cam and oil pump and in the process of the install of the oil pump slide it over shim stock on the pan gasket, did not undue the pan bolts, on reassembly put the pump on like you would an LS3 in installed the base first slide over shim stock so I would not damage the pan gasket, the pump bolts have black plastic injected into the over sized pump holes so there is no way to move the pump centring on the crank it only goes in one place unlike say an LS3 pump where you use shim stock to centre on the crank, reinstalled the gears as they cam out as I marked each one on disassembly. Have started the engine run it briefly, have oil pressure at idle 50psi-70psi but oil level was probably over filled by me as the engine sat a couple of months waiting on my heads to be done and I believe the dry sump tank drained down into the engine. After running drained all the oil and only got 8l out yet think I put by mistake 12-13l in. I assume the pan gasket is leaking so the pump does not scavenge properly but how is the oil getting into the exhaust system, also the plugs are all oil fowled. Just about to start disassembly any ideas as to what I screwed up.
12-12-2018, 02:26 PM
#3
Instructor
Thread Starter
Just started taking it apart again and know where the missing 5 qts oil went it is in the intake manifold. Still have no clue as to how it would get there, obviously through the crankcase breather system but why is the question. All because of a failed gasket to the oil pump?
12-12-2018, 04:17 PM
#4
Le Mans Master
I think you answered you own question - you over-filled the sump by 5 qts, yes?
if so, you came very close to hydrlocking the engine - clean everything up, refill to the proper level and go buy a lottery ticket before your luck runs out.
And yes, if you let the car sit long enough, most of the oil will drain out if the tank, giving the impression it's empty (when it isn't). Just don't make that mistake again.
if so, you came very close to hydrlocking the engine - clean everything up, refill to the proper level and go buy a lottery ticket before your luck runs out.
And yes, if you let the car sit long enough, most of the oil will drain out if the tank, giving the impression it's empty (when it isn't). Just don't make that mistake again.
12-12-2018, 06:31 PM
#5
Drifting
As Dan said...you just got very lucky. Very few have overfilled and didn't lock up or destroy the motor. Drain both drain plugs, clean up the motor at the intake, and blow out the cylinders by cranking it with no spark plugs. Start over with the right amount of oil for your year. Cross your fingers you don't have a bent rod, and don't do that again.
12-12-2018, 06:42 PM
#6
Le Mans Master
Just started taking it apart again and know where the missing 5 qts oil went it is in the intake manifold. Still have no clue as to how it would get there, obviously through the crankcase breather system but why is the question. All because of a failed gasket to the oil pump?
Last edited by Mr. Gizmo; 12-12-2018 at 06:43 PM.
12-12-2018, 08:27 PM
#7
Drifting
well in the process inside the engine. the oil return stage of the pum did what it was designed to do and returned it to the oil tank. it then went through the vent tube, into the intake. So much that it came out the exhaust. Now here is what I would do.
- Oil change and put the correct amount in, so you are 100% sure
- Pull all the plugs out and with a towel draped over the inner fenders on both sides, turn the motor over. Disconnect the coils too
- Brake clean in each cylinder
- Pull the intake off and clean it out as best as you can
- Do a compression test (google how if you dont know)
If all checks out, put everything back together and run the **** out of it to push the excessive oil out of the exhaust. For a few weeks put some cardboard under the exhaust tips, they will probably drip for a while.
- Oil change and put the correct amount in, so you are 100% sure
- Pull all the plugs out and with a towel draped over the inner fenders on both sides, turn the motor over. Disconnect the coils too
- Brake clean in each cylinder
- Pull the intake off and clean it out as best as you can
- Do a compression test (google how if you dont know)
If all checks out, put everything back together and run the **** out of it to push the excessive oil out of the exhaust. For a few weeks put some cardboard under the exhaust tips, they will probably drip for a while.
12-12-2018, 08:28 PM
#8
Drifting
12-12-2018, 08:56 PM
#9
Instructor
Thread Starter
Found out why it pulled 4 qts of oil into the intake, I have an oil separator installed between the valley cover and the intake but in my own stupidity I switched it with a line from a T I have in the valve covers going to the dry sump tank so what happened is it pulled 20+ inches of vacuum straight from the drivers side valve cover straight into the intake and because of this also there would be virtually no vacuum at the dry sump tank to help the scavenge side of the oil pump. Got the intake off now and drained all the oil out of it and am in the process cleaning oil up from the exhaust etc will hand crank the motor over with the plugs out and drain all the oil and put it all back together and cross my fingers and hope. If its good I will go buy a lottery ticket, when it did not start the last time it was only against the starter motor so think it is probably okay.
12-12-2018, 11:53 PM
#10
I would do the instructions from V8sten less spraying brake clean in the cylinders. You shouldn't need to turn the motor over too much to get the excess oil out. Just send every piston up a couple of times, put a some cheap NGK plugs in, and fire her up. Let it run till for a minute or two to burn the excess oil left in the cylinders and then shut it out and replace the spark plugs again if they look like ****.
12-12-2018, 11:55 PM
#11
Burning Brakes
Not to be a negative Nancy but starter motors can bend rods. Maybe not ls7’s but many rods have been bent with the starter motor alone.
And i I would highly recommend against spraying brake cleaner in your cylinders.
And i I would highly recommend against spraying brake cleaner in your cylinders.
12-13-2018, 11:04 AM
#12
Instructor
Thread Starter
I will not be spraying brake cleaner in the cylinders, and I have turned it over by hand and it feels fine, hopefully get it reassembled today and fired up. Will post the results when i do.
12-13-2018, 12:35 PM
#13
Drifting
Woowee, I overfilled mine by 2-3 qts before I tuned/dyno'd my Z. Oil was pushing through the lines and into my intake, I laid down 572 SAE and then checked the oil and was over-filled a few inches. I immediately changed oil, the previous oil change I did not know there were 2 drain plugs, as it was the first time I changed oil in the car lol.
12-16-2018, 10:40 AM
#15
Drifting
Wow! Thats good news! I feared a bent rod. You took the criticism well! LOL I think your well versed in the oil change of the Zo6 dry sump system now! Best of luck. Just remember 06-08Z is different amount than 09-13Z.