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Discussion Starter · #1 ·
Lot's of questions about the PVC system in the 2nd gen Traverse (2018-2021):
Does anybody know if the 2nd gen with the LFY engine has any type of stock oil separator for the PVC system? I'm considering an oil catch can but don't want to add one if it's not really needed. Under the engine cover I see what appears to be a large PVC valve (outlined in yellow in the pic below) and an airbox that sits on top of the intake manifold and may possibly contain some type of oil separator (outlined in red in the pic below).

Has anybody with a 2nd gen had problems with oil burning or carbonized intake valves once they hit higher mileage? i have seen some instances of it on gen 1.

Finally, does the LFY PVC system only have a connection to the front valve or is there also one going to the rear valve cover?

Maybe for 2022 Chevrolet will transition the Traverse over to the LGZ engine which has an active oil separator built in. It scavenges oil from the PVC system and dumps it back to the crankcase. Therefore no carbon buildup on the intake valves. Colorado uses that engine now and people seem to be pleased with the results.

2021 Traverse PVC and Airbox
10436
 

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I don't know the exact answer to your question, but what you boxed in yellow sure looks like it's within the normal PCV dirty side pathway. It looks to me like that cylinder must be there to force the air to make a bunch of twists and turns to slow it down and let suspended solids drop out and drain back. It does not appear to be serviceable.
 

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I have not had the engine cover off my '20 Traverse but I have put a catch can on my 3.6 Equinox.
On it the dirty side of the PCV, vacuum side, that connects to intake manifold is on the firewall side valve cover. Fresh air is taken into motor on the rad. side valve cover. It's connection to clean air has a small chamber at intake tube to catch any droplets from WFO blow by.
In the picture one would need to pull off the ''box'' outlined in red and see if it's connected to the rear valve cover to see if it has multiple functions. Looks like a rear connection on it is PCV dirty side, what's visible from intake tube probably connects to the small one in yellow which looks like a small catch for WFO blow by. I suspect that assembly has 2 functions routing clean air into the yellow and oil separating in the the red box. I don't picture them retooling valve covers, cheaper to make a plastic box and hoses to control oil mist.
 

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Discussion Starter · #5 ·
Ha! I couldn’t go longer than a week after getting the vehicle before I ppopped the engine cover off. I was curious what was hidden under it and that’s when I noticed the unusually large PVC valve. For the large black plastic box in red, once it’s time to replace the air filter, I’ll remove that box too and study it more closely to see where all it connects to, and report back. At that point, I also want to check the air intake to the throttle body to see if there is any oil present.
 

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Ha! I couldn’t go longer than a week after getting the vehicle before I ppopped the engine cover off. I was curious what was hidden under it and that’s when I noticed the unusually large PVC valve. For the large black plastic box in red, once it’s time to replace the air filter, I’ll remove that box too and study it more closely to see where all it connects to, and report back. At that point, I also want to check the air intake to the throttle body to see if there is any oil present.
Even if the Traverse doesn't have one of the nice oil separators, the Traverse really hasn't had any oil burning issues through the PCV since the 2012 update on the LLT and I haven't heard of any on the 2nd gens. In fairness to Chevy they seem to have figured out the PCV design and their revised oil specs (full synthetic, min. NOACK and shorter OCIs) kept the oil fresh enough to prevent sludge buildup in the PCV.
 

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Discussion Starter · #7 ·
Thanks. Good to know. I'm a little paranoid having experienced the Subaru oil burning fiasco in the past.
 

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Thanks. Good to know. I'm a little paranoid having experienced the Subaru oil burning fiasco in the past.
I tend to check my oil every couple weeks or so, if I see my Traverse start to lose an appreciable amount of oil between changes I'll look into refurbishing the PCV system or possibly adding a catch can. Right now it doesn't burn any so I'm not going to fix what isn't broken.
 

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@Hauler

I have a 2019 Traverse, and was also considering a catch can. After seeing earlier posts similar to what others have mentioned above, I was less worried about the need for a catch can. However; at about the 8K mile mark I did exactly what you have shown in the photo above; I pulled the engine cover and discovered that same "PVC/baffle-trap" that you have outlined in yellow. I then took it several steps further; 1) I disconnected the hoses on both ends of that device. What I found was the upper hose was bone dry, the lower hose had an almost undetectable film. Others on here suggested I "take one for the team" by sacrificing that device by cutting it in half to see what it really is. However; seeing that it seems to be doing it's job I left it intact. 2) I then unhooked the intact tract downstream of the MAF sensor (upper left area of your photo) and found absolutely NO trace of any oily film.

My conclusion: GM seems to have fixed the concern of PVC vapors issues getting into the intake. I'll recheck #1, #2 when I hit the 20K mile mark to know for sure
 

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Discussion Starter · #12 ·
@Hauler

I have a 2019 Traverse, and was also considering a catch can. After seeing earlier posts similar to what others have mentioned above, I was less worried about the need for a catch can. However; at about the 8K mile mark I did exactly what you have shown in the photo above; I pulled the engine cover and discovered that same "PVC/baffle-trap" that you have outlined in yellow. I then took it several steps further; 1) I disconnected the hoses on both ends of that device. What I found was the upper hose was bone dry, the lower hose had an almost undetectable film. Others on here suggested I "take one for the team" by sacrificing that device by cutting it in half to see what it really is. However; seeing that it seems to be doing it's job I left it intact. 2) I then unhooked the intact tract downstream of the MAF sensor (upper left area of your photo) and found absolutely NO trace of any oily film.

My conclusion: GM seems to have fixed the concern of PVC vapors issues getting into the intake. I'll recheck #1, #2 when I hit the 20K mile mark to know for sure
Thanks for the feedback. It puts my mind at ease.
 

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