[Bx Tpr]

I found residue around the oil fill cap a few weeks ago and cleaned it up thinking it was from the last oil change. I’ve cleaned it twice already and it’s back again. Is this is a common issue on the ZL1?
Also found an oil spray pattern on the oem intake elbow where the clean side pcv system gets its vacuum.

[SD1]

Actually appears to be leaking from the sensor just below the fill cap toward the center of the motor. Clean it and check again or just take it to the dealer, thats an issue I would want resolved quickly mostly because its making a mess.

[Elite Engineering]

What your seeing is not uncommon as the factory PCV system is not a good design for a boosted engine. Look into our E2-X dual valve system that will not only the seepage issue in most cases, but also there is a ton of oil ingestion internally you don;t want with a GDI FI engine.

[SD1]

My bad, I thought the last pick was a close up of the oil filler tube. Still looks like there is a leak at that sensor socket below, oil leaks typically migrate front to back.

Is the poor PCV system why you would need a catch can?

[hashtag]

This happens on low mileage LT4 engines. I’ve seen it numerous times on different CTSV,ZL1 & Z06 models. It goes away

[Bx Tpr]

Thanks for the help. I took the plastic cover off to make sure it wasn’t something big and it’s either one of the valve cover bolts might be loose or the oil fill cap is just not keeping the oil in. The plastic extension piece that’s attached to the valve cover is loose and there is no way to tighten it. You can see the blue o-ring in the picture that’s supposedly sealing it.

[hashtag]

It will go away. If it keeps happening if you have more than 5K mileage then it’s an issue. On all three of my ZL1 this has happened.

[Bx Tpr]

Originally Posted by hashtag

It will go away. If it keeps happening if you have more than 5K mileage then it’s an issue. On all three of my ZL1 this has happened.

Not doubting you at all. Just wanted to see where the hell its coming from. After looking at the back side of the plastic cover I’m certain it’s from the oil fill tube. The sound proofing on the back has absorbed most of it and you can see it’s misting out past the oring of the fol tube.

[hashtag]

Originally Posted by Bx Tpr

Not doubting you at all. Just wanted to see where the hell its coming from. After looking at the back side of the plastic cover I’m certain it’s from the oil fill tube. The sound proofing on the back has absorbed most of it and you can see it’s misting out past the oring of the fol tube.

It seems like during the break-in time that plastic expands & it just naturally stops. You dug into it now so you might have to switch it out.

[White_1LE]

Reviving and old thread here, apologies if there is a better thread already. I did do a search and didn’t find others.

My 19 ZLE is doing this exact same thing. The pictures are literally a carbon copy of what I have going on. I noticed it around 1500 miles a few years ago might have been there earlier even, and I have just been giving it a brake clean wash here and there but it is still doing it at 9800 miles. Car is stock aside from a standard Roto Fab intake, Katech ported stock TB and a mid pipe. I do occasional AutoX but mostly street driving (decent amount of shenanigans mixed in on the street though). The engine uses nearly zero oil between changes. I really don’t tolerate leaks on any of my vehicles so this is not something I can just ignore or pretend I didn’t see.

I don’t think it is going to go away on its own. I did take it to a local dealer but they were clueless and useless.

So how common actually is this? And is the right solution an aftermarket catch can? Is it just building too much crankcase pressure and oil is getting past the oil fill cap/tube.

I appreciate the insight and any help!

[Booher]

I asked this same question a few weeks ago when I noticed mine. Another zl1 owner told me that's what happens when you run the car hard, it "boils" the oil is what I was told. Sounded strange, when Inasked on here I was told not to worry about it. Glad, well not glad, to see others with it too.

[White_1LE]

Yeah I don't think you/we are actually boiling the oil. That would take some pretty insane abuse to get the oil that hot. At least I know I am not getting it that hot. The car sees WOT multiple times, every time I drive it though. I mean that's sort of the point of owning one of these cars.

I think this is more of a pressure situation where the crankcase pressure rises (even more so on a boosted engine) while oil vapor/splashing is also increasing with heavy load and high RPM and the oil is finding the path of least resistance and migrating past that O-ring on the filler tube and maybe the cap too for some people. Even just the rise and fall of crankcase pressure could be making that O-ring "walk" up and down which results in oil seapage. Like it almost wipes tiny bits of oil up and down as it moves tiny amounts with crankcase pressure changes.

I don't know, I am by no means saying I have data that proves that, just hypothesizing since I don't have a solid root cause analysis and solution statement to go off of even though I am not the only one with the problem and this engine platform is many years old at this point. If it was one easy to define problem, we would all know by now.

But this has me looking at something like the Mighty Mouse catch can system as a solution since it allows a pressure relief of the crankcase and PCV system under heavy load/high RPM/high boost situations. But I DO NOT want a bunch of crankcase fumes floating around in my engine bay, getting in the car, etc. F that. I have had cars with open element catch cans or breathers and they are horrible for a street driven scenario. My GTA would force me to just immediately take a shower and put my clothes in the wash after driving it around town for an evening. That was at least understandable since it was more old school and more strip than street prepped. I will not be OK with that on my ZL1.

[Booher]

That sounds much better than what I was told, lol.

[Evansa22]

Originally Posted by White_1LE

Yeah I don't think you/we are actually boiling the oil. That would take some pretty insane abuse to get the oil that hot. At least I know I am not getting it that hot. The car sees WOT multiple times, every time I drive it though. I mean that's sort of the point of owning one of these cars.

I think this is more of a pressure situation where the crankcase pressure rises (even more so on a boosted engine) while oil vapor/splashing is also increasing with heavy load and high RPM and the oil is finding the path of least resistance and migrating past that O-ring on the filler tube and maybe the cap too for some people. Even just the rise and fall of crankcase pressure could be making that O-ring "walk" up and down which results in oil seapage. Like it almost wipes tiny bits of oil up and down as it moves tiny amounts with crankcase pressure changes.

I don't know, I am by no means saying I have data that proves that, just hypothesizing since I don't have a solid root cause analysis and solution statement to go off of even though I am not the only one with the problem and this engine platform is many years old at this point. If it was one easy to define problem, we would all know by now.

But this has me looking at something like the Mighty Mouse catch can system as a solution since it allows a pressure relief of the crankcase and PCV system under heavy load/high RPM/high boost situations. But I DO NOT want a bunch of crankcase fumes floating around in my engine bay, getting in the car, etc. F that. I have had cars with open element catch cans or breathers and they are horrible for a street driven scenario. My GTA would force me to just immediately take a shower and put my clothes in the wash after driving it around town for an evening. That was at least understandable since it was more old school and more strip than street prepped. I will not be OK with that on my ZL1.

Mighty mouse also makes a road course top which replaces the filter on top of the can. It directs any relieved gases through a hose coming off the top of the can and the other end can be placed wherever you'd like the gases to exit. Mine comes out near the wheel well at the bottom of the car in an easy to reach location along with the hose to empty the can.