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So I decided to take my z06 to the track and run it on the road course. On my third session the car decided to dump the majority of the engine oil out...
its a 17 Z06 with heads, cam, ported blower, pulleys, etc so I decided that there was probably no sense going to my local dealer looking for warranty. The good news is that it never ran dry out of oil and had oil pressure until I shut the car off, the other good news is it never burnt to the ground! I guess the flames coming out under the car looked good to the spectators!
So just before I loaded the car to bring it home I quickly fired the car up (made sure it had oil in it and psi) and the car ran a little rough but no oil leak. What the.... then about 20 seconds later oil came pouring out in front of the front passenger tire.
Anyways I trailered the car home and put it on my lift and started disassembling the car. Engine Oil everywhere. All over the front of the motor, steering rack, and under the whole car. But as I removed the cold air and underbelly panels I expected to see something obvious considering how fast the car was dumping oil. Can't see any issues? Nothing obvious anyways.
Any ideas? I can't seem to find the issue. My next step is to fill the sump with oil and see where it comes out but I would like to avoid the mess if possible. Anyone else have this issue?
Thanks
Just a guess, but sounds like the oil line that runs from the radiator to the dry sump system came undone. Its on the passengers side of the radiator, I believe.
Just a guess, but sounds like the oil line that runs from the radiator to the dry sump system came undone. Its on the passengers side of the radiator, I believe.
So I know of the the 2 main lines from the dry sump to the pan and back to the dry sump but there is another line that runs from the dry sump to the rad? I will take a look and see if I can locate that.
Clean the mess up the best you can. Add a couple of quarts and start it up. As soon as it starts spewing oil, shut it off. It's hard to tell where a pressurized oil leak is coming from just by looking.
Update- I cleaned the car up. Removed the air intake and took a good look around. Nothing. So I put oil in the car (topped it up) slid the intake on without a filter and got my wife to fire up the car. It ran beautifully. For about 5 seconds. Then it started to stumble and probably a total of 15 seconds and died. But no oil leak. So I looked in the intake and it right full of oil. Intake had approx 1/2 a gallon of oil in it.
So car car does not smoke, runs great but decides it dislikes having oil in it and wants to puke it out through the intake. Thoughts on why it's pushing oil into the intake?
Best guess is the check valve in the system that vents excess crankcase pressure into the intake tract has failed and is now sucking oil into the intake system. Someone who has installed one of the aftermarket catch cans can probably supply some direction on where to look.
Having an LS7 suddenly start belching oil all over the engine compartment at a track event I was going to suggest checking the front cover gasket (it was difficult to find that leak on the LS7), however, if you have oil in the intake I suspect you have some sort of issue with the installation of your mods or have some damage inside the engine causing oil to be pushed through the PCV system.
Does your car have an after market catch can on it?
Also check to see if any of the PCV lines are crimped.
Recommend draining all of the oil out of the car from both plugs.
Then refill with 10 qts.
It may be over filled.
When a dry sump system is overfilled the PCV system will siphon oil and burp it out into the intake.
I know it shouldn't be overfilled. However if the last oil change procedure wasn't done properly and from both plugs until completely drained, and then the car was refilled with 10 qts, you/nobody knows how much oil is actually in the car now.
Last edited by dar02081961; 05-17-2019 at 03:59 PM.
No catch can. It's far more significant then a crimped pcv hose. Well I don't have an official answer yet but I do know there is fuel mixed with the oil. I think I have an issue with a piston or ring. I will let you know how I make out but I am pretty confident it's a significant issue. Car runs for a bit, stumbles, pushes oil out the pvc and is mixing fuel with the oil.
Cool ...or I guess I should say not so cool...Let us know.
Not a lot of situations on an LT4 that can put fuel in the oil without being blatantly obvious.
I would NOT crank that car up again until it was 100% torn down and problem solved. Pull each plug, pull the coil packs off, supercharger, valve covers, ensure the oil and sidekick tank lines are not leaking, bent, broken, look at the front crankcase seal (common area of leaking it's weak on LT4's). Make sure the PCV check valves are fine. Can only blow air one way. You could be getting positive pressure into your PCV system causing it to blow oil out the vent line into your intake track. Not good. You don't want any kind of no compressable fluid like oil/water in your intake system and trying to crank it. After you pull the plugs get a small camera look in each cylinder, OR get a compression gauge and check the compression of each cylinder. I have had a hole in a piston before causing boost blow by pressurizing the crankcase, PCV system. Not good. Not saying that is happening just ensure you haven't caused any damage to your cylinder walls, scuffing, ring lands, etc. I would not be cranking or running that motor with oil issues like that personally.
If your getting fuel with the oil, it might be coming from the cylinders. Take out the spark plugs, or pull the blower off and take a look around.
Well I have the Motor about 50% ready to come out. Thanks to fryeant on the write up to remove it!
All plugs look good. All headers pipes look similiar inside. Has anyone experienced a stuck injector on a lt4? Just grasping at straws at the fuel in the oil and the pressurization of the motor. Would a stuck injector pressurize the motor enough to push oil out the intake? Just thought I would see if that has happened before I have the motor on the floor and it was something simpler.
Going to to do a compression test now and pending those results will tell me if I finish pulling the motor out......
Last edited by s-cam; 05-26-2019 at 11:58 AM.
Reason: Spelling
Well I have the Motor about 50% ready to come out. Thanks to fryeant on the write up to remove it!
All plugs look good. All headers pipes look similiar inside. Has anyone experienced a stuck injector on a lt4? Just grasping at straws at the fuel in the oil and the pressurization of the motor. Would a stuck injector pressurize the motor enough to push oil out the intake? Just thought I would see if that has happened before I have the motor on the floor and it was something simpler.
Going to to do a compression test now and pending those results will tell me if I finish pulling the motor out......
I have had a stuck port injector and NO it won't force oil out your intake. Especially a DI injector b/c they are squirting fuel into the cylinder directly, not into the intake runner as a port injector would. When you get an injector stuck open it will throw tons of misfires, essentially fuel puddling the cylinder. It's not good. You can also hydro lock the motor that way. I run ethanol and in my case it happened at Daytona International Speedway my headers were so hot it lit the unburned fuel up and I could see flames in my rear view. No damage but it could have been bad. Once I knew it was a stuck injector I didn't do **** until I got all the plugs out and identified the injector. Do not crank a motor over if you think you have a stuck open injector. Will have a bad day.
i figured I would post the solution in case anyone else has a similiar issue
so I had the injectors tested. They tested good to 140lbs (could not find someone local to test them to the rated psi), so then I did a compression test. It tested good. 200lbs a hole. But I pulled the motor anyways and we tore it down. No issues. Motor is perfect. So then We put it all back together and back in the car. I only put 6 litres of oil in the car and ran it. It ran for approx 3 min and dropped oil pressure. Poor oil pressure due to fuel in the oil again. Drained the oil and had approx 6 litres/quarts of gas in the oil again. Knowing the shortblock was good I was able to elinimate that. So tore the supercharger off and pulled the hpfp.
SEAL is pushed out on the drive shaft on hpfp
if you are getting fuel in the oil and pushing liquid into your intake check the hpfp.
05-16-2019, 12:26 AM
Z06 engine oil leak
