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#1 | |
![]() Drives: 2018 ZL1 1LE Join Date: May 2022
Location: Salt Lake City
Posts: 138
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ZLE Oil Burning Nightmare
Hey all! I am currently going through a nightmare with my ZLE involving oil consumption, and am looking for any help I can get at this point.
For context, the car got sent to my mechanic earlier this year for a relatively routine cam/valvetrain upgrade with some supporting mods such as a 10% overdrive pulley and an Elite Engineering E2X catch can. Once he wrapped it up, right before it was about to be strapped down to the dyno for tuning, the car started making a nasty ticking noise; turns out it spun two rod bearings so the motor was then torn apart for a rebuild. Once the car was finally rebuilt and tuned, it made strong numbers and has been running great. However, I have been having excessive oil consumption and oil smoke. It has consumed about 2.5 qts in 1700, admittedly spirited, miles. It smokes pretty bad on cold starts, and often times even worse on lukewarm starts (when you shut off the car and let it sit for 15-30 minutes). Doesn't seem to smoke at all under load. Here is a video I caught of an especially bad cold start: https://youtu.be/6l_-c8zVg-0 Compression came back healthy at 180 lbs on all 8 cylinders with very little variation. We have not done a leak down test which I am planning on doing soon. My immediate instinct (as well as my builder's) was valve seals (the machine shop had installed these seals while the block and heads were in for hot-tanking, so we figured it was possible they had messed up installation). However, upon removal of the plugs and valve covers, all 8 plugs were fouled about equally and visually the entire valve train (seals included) looked okay, so my builder pumped the brakes on valve seal replacement. My builder is now thinking this is related to my Elite Engineering E2-X catch can. He says that since it uses the stock PCV valve he thinks the increased crankcase pressure and is pushing excessive amounts of oil into the floor of the blower through the PCV valve, and he thinks the solution to our problem is the following PCV valve replacement from Mighty Mouse: https://www.mightymousesolutions.com...t4-pcv-adapter While I hope he's right, my gut is telling me this is likely not the cause of such excessive oil smoke and oil consumption. My big fear is that during the rebuild, he opted to reuse the piston rings and not hone the cylinder walls, as the factory cross-hatch was still visible and the rings were in good shape with only 20k miles on them. I worry this did not work out in our favor and now I'm having piston-ring induced oil consumption. All this is to say: at this point I'm pretty discouraged and lost as to where to go from here with diagnosis. I'm planning on running a leak down test soon to hopefully give some more info, but ANY insight I can get at this point would be awesome. |
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#2 |
![]() ![]() Drives: 2017 2ss 6mt Join Date: Mar 2024
Location: dallas
Posts: 952
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Why don't you try taking the catch can off and setting it up like stock for a little while? If you think the catch can is the problem then it's easily removed and eliminated as a problem.
Since a catch can is just a trap for liquid oil that is put inline with the pcv system, i would doubt the catch can would be the problem. It would be more likely the hose routing would be incorrect or the pcv valve. If you're pushing so much pressure in the crankcase that its outflowing the pcv valve then it's probably in the rings. |
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#3 | |
![]() Drives: 2018 ZL1 1LE Join Date: May 2022
Location: Salt Lake City
Posts: 138
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#4 | |
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Super Stock
Drives: Chevrolet Camaro ZL1 Join Date: May 2022
Location: Concordia
Posts: 783
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Quote:
I don't sit well with Catch Cans (for reasons I won't get into), but I do think he may benefit from running the stock style set up as well to see how he fares out. If he keeps smoking after the fact then it's definitely a ring issue. Hey Samyyyyy, what weight and brand oil are you using? What are your mods as well? One more food for thought footnote. You may have a lot of oil in the general system as it stands because of all the oil that is in the intake and valve areas of the engine. It may not stop smoking for a while, my advice would be to try and remove the supercharger lid if you have the means and resources to do so and just wipe the area down that way you can clear out some of the fresh oil that is probably all up in there.
__________________
2017 Red Hot ZL1 A10 - Apex ARC-8's, 305/ 325 PS4's, DSX 9.06 12% lower, Griptec 2.5 upper, NGK HR7 Ruthenium plugs, Nostrum 22+ injectors, XDI Goliath HPFP, Katech dual in tank low side pump, Katech oil pump, LME tensioner, DOD delete, LT1 big fuel cam, Jokerz ported blower, MPI lid, GMS hood extractor bracket, Soler ported 87mm (91mm eff) TB, Granatelli SS plug wires, Cordes LTR reservoir, DMS T-stat housing, 186* LS3 T-stat, Black Widow Angry Housewife/ Corsa NPP mufflers, Borla X pipe, BMR engine mounts, Banks iDash, Lithium Battery, AEM X- Series, HP Tuners, E85, 16.5 psi
834 HP/ 840 TQ |
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#5 | |
![]() Drives: 2018 ZL1 1LE Join Date: May 2022
Location: Salt Lake City
Posts: 138
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Quote:
Oil weight: 0W-40 Mobil 1 Mods: -BTR Stage 2 (+ all supporting mods; pushrods, springs, retainers, Johnson 2110R lifters, timing chain + LME chain guide, Katech pump, etc etc etc) -Kooks 1 7/8" LTH -> Corsa NPP -Big Gulp -10% Lower + ATI Balancer -DSX Flex -EE E2X Catch Can -JMS BAP In our replacement of the PCV valve, I'm going to take a peak under the blower lid since it needs to come off anyway, and clean out anything that is in there. |
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#6 |
![]() Drives: Chevrolet Camaro ZL1 Join Date: Sep 2019
Location: Planet Earth
Posts: 80
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I would do the leak down test. That will tell you if it is ring/cylinder wall issue. I doubt it's the catch can. I'd still be suspicious of the valve guide seals.
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#7 | |
![]() ![]() Drives: 2017 2ss 6mt Join Date: Mar 2024
Location: dallas
Posts: 952
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Valve seals show their failure in long idle and on startup more than any other time. They are also a big contributor to carbon buildup on valves, because they leak oil into the hot valves of a non running engine. Not saying they dont leak when driving, it just shows more at idle and leaving from a stop. Signature big bluish grey cloud in the face of the car behind you. Leaking rings will be smoking pretty much all the time. You will be able to see the trail following you when going down the highway. Ive been doing valve seals on the LTG engines more often at work lately, the 2013-2015 ATS and CTS. I dont really know if they changed the valve seals to a different design when they started the 2016 LTG for the camaro and ATS but i do know the ones i get from GM are different than the ones i remove. |
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#8 |
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fo'shizZL1
Drives: 2017 ZL1 Join Date: Aug 2017
Location: ATL
Posts: 1,805
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If you put the MM pcv diverter in, you need to put a restrictor in the vacuum line of the catch can. Otherwise, since the hole is so large in the MM piece, you will be pulling even more oil into the catch can and overflow it quickly.
That E2X can should have come with a replacement piece from Elite that is very similar to the MM piece, except it has a small orifice in the back. In any case, I don't think the catch can is your problem here. Good luck!
__________________
2017 ZL1 M6 Black | Maggie 2650 // 103TB // Big Gulp // CSP LT's & Ultra Cats // BMR MM // BC Forged KL13
Mods being installed- oil pump, cam, ported heads, dual in-tank, Goliath and XDI, corn, etc., etc. |
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#9 | |
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Drives: 2021 ZLE, C5 Z06 6.0L Procharged Join Date: Mar 2023
Location: South Carolina
Posts: 466
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First off, lets ditch the Mobil1. You have a lot of money invested into your engine, stop making GM happy with EPA Rated Oil as I promise you will get better ring seal with the recommended 15W50 and never see a difference in MPGs. I recently tracked my ZLE for two days at Road Atlanta, with 14k+Miles on track and 36K total on the original engine, did not burn a bit of oil over the two days on track. At the end of the track day, I swapped the track wheels & tires for the street ones, flipped the upper strut mounts to my street alignment and loaded the car in the trailer for its ride back to Darlington, SC. The next day, we unloaded the car from the trailer... loaded it full of luggage and stuff for a weekend at Daytona International Speedway and drove 8 hours to St Pete for two days with Family for Turkey Day. All in all we traveled to Daytona Friday morning, the streets of Mexico Friday & Saturday Night and then to the Cabin on the St Johns River. On Sunday we drove home with a stop in Savannah and Tybee Island for a sunset with friends. By Midnight, we were back home having traveled 1600 miles in total for the week and a best MPGs recorded of 24.4... using about a pint of oil from the previous top-off BEFORE the track day! So let's address the Elephant. I bought an Elite CC and its sitting on the shelf collecting dust. Your ZLE comes with a Air-Oil Separator (AOS) from the factory that actually drains collected oil back to the oil pan. Its a bit rudimentary but it does a decent job. What I have done is add two $39 Amazon Evil Energy catch cans to act as an intermediary going from the VC to the Catch Can and then to the OEM AOS on both sides. So let's discuss what I am designing now, using the Improved Racing CCR .5L (IR CCR) closed loop system. On the Driver's Side the valve cover has a tendency to fill up full of oil during long sweeping carousel turns on the track with high RPMs using the PCV vent point... having TWO small Catch Cans shows exactly which side is offering more oil. After a day at Carolina Motorsports Park where we have a long sweeper, I might get a couple ounces of oil in the driver's side CC. I now have added an angled and extended Oil Filler Tube with a -10AN fitting and a 5/8" hose from that PCV VC pickup connected to that mount on the Oil Fill Tube. It will go from this point to the front of the passenger side by the radiator inlet to the new IR CCR. The Passenger side will also tee into the inlet of this CC as well as the port under the Supercharger which until this point has been left untouched. I am contemplating the complete removal of the OEM AOS and utilizing the drain function of this impressive CC system to automatically drain back to the crankcase. I believe at this point I will render oil vapor in my application a moot issue as you see, I have zero issue with ring seal or blow-by since removing the OEM Oil Cooler which is garbage as well as the #1 issue robbing your car of proper fueling. Let's dive into the Oil Cooler ruining your day... bet you didn't know it was! So just stare at it for a while and understand GM built your car for somewhere between the little girl who gets it for Graduation to Guys like us who will beat it to death on a track! Somewhere in between it had to pass a climate test and to do that, multiple systems are combined thermally. Unfortunately, the oil system is one of those. The engine Oil cooler gets its coolant from the lower driver's cold side of the radiator, mixes it with the hot watery Mobil-Junk oil and then dumps that heated coolant into the driver's side block, while the rest of the colder coolant circulates from the passenger side at about 80-110º cooler temps!! This disparity in temps is missed by your engine's calculations because its looking at a sending unit that is on the passenger side by the thermostat... unfortunately the #3 & 5 cylinders are destined to a life of over-fueling, rich mixtures and poor ring seal as well as valve guides that get washed with unburnt fuel which by the cam you have and the overlap... can be pulled into the oil mixture. These are just the broad strokes... send me a DM and lets talk! I have built a system that is proven to work on the track and be docile enough to be amazing on the street. |
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#10 | |
![]() Drives: 2018 ZL1 1LE Join Date: May 2022
Location: Salt Lake City
Posts: 138
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#11 | |
![]() Drives: 2018 ZL1 1LE Join Date: May 2022
Location: Salt Lake City
Posts: 138
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Quote:
Oil: Yeah, I'm planning on ditching the Mobil 1 stuff soon. I've heard good things about Amsoil and Redline. What 15W-50 are you using? Oil cooler: I totally forgot to mention that I have Gabe's thermostatic oil cooler setup installed already, so that should be a non-issue right? |
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#12 | |
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fo'shizZL1
Drives: 2017 ZL1 Join Date: Aug 2017
Location: ATL
Posts: 1,805
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Quote:
__________________
2017 ZL1 M6 Black | Maggie 2650 // 103TB // Big Gulp // CSP LT's & Ultra Cats // BMR MM // BC Forged KL13
Mods being installed- oil pump, cam, ported heads, dual in-tank, Goliath and XDI, corn, etc., etc. |
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#13 | |
![]() Drives: 2018 ZL1 1LE Join Date: May 2022
Location: Salt Lake City
Posts: 138
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Quote:
I'm wondering the same thing. Here are some screenshots of our text thread to provide some context on the situation. |
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#14 |
![]() ![]() Drives: 2017 2ss 6mt Join Date: Mar 2024
Location: dallas
Posts: 952
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and the story unfolds
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