Catch can flow discussion

[BlaineBug]

The presenter in this clip mentions that the passenger side PCV system does the "majority" of the heavy lifting, necessitating the need for 2 cans. Truth or sales gimmick??

 

[donjetman]

The presenter in this clip mentions that the passenger side PCV system does the "majority" of the heavy lifting, negating the need for 2 cans. Truth or sales gimmick??

They are trying to sale something you don't need on the (clean) passenger side.

PVC system air flow on the passenger side is clean filtered air via plumbing and flow "INTO" the passenger side valve cover. No catch can needed on that side.

Where the catch can is needed is on the driverside/dirty side. The passenger side filtered air becomes dirty air because of blowby gases, and oil (not good) are being sucked "FROM" the driverside valve cover and into the intake manifold. Our engines are not suppose to burn oil.

The original valve covers on our 2007 to 2011 LS engines were poorly designed and allowed too much oil to be sucked out of the engine via the passenger side valve cover (PVC) thus leaving deposits on the intake valves, combustion chambers, pistons, and sometime even sticking the piston rings (my engine).

So GM around 2014 came up with new designed driverside valve covers, for years 07 & 08 = pt# 12570427; and for years 09-11 = pt# 12642655 to minimize the oil being sucked out of the engine.

https://f01.justanswer.com/ebrock63...il+Consumption,+MIL+ON,+Engine+Runs+Rough.pdf

 

[BlaineBug]

They are trying to sale something you don't need on the (clean) passenger side.

PVC system air flow on the passenger side is clean filtered air via plumbing and flow "INTO" the passenger side valve cover. No catch can needed on that side.

Where the catch can is needed is on the driverside/dirty side. The passenger side filtered air becomes dirty air because of blowby gases, and oil (not good) are being sucked "FROM" the driverside valve cover and into the intake manifold. Our engines are not suppose to burn oil.

The original valve covers on our 2007 to 2011 LS engines were poorly designed and allowed too much oil to be sucked out of the engine via the passenger side valve cover (PVC) thus leaving deposits on the intake valves, combustion chambers, pistons, and sometime even sticking the piston rings (my engine).

So GM around 2014 came up with new designed driverside valve covers, for years 07 & 08 = pt# 12570427; and for years 09-11 = pt# 12642655 to minimize the oil being sucked out of the engine.

https://f01.justanswer.com/ebrock63...il+Consumption,+MIL+ON,+Engine+Runs+Rough.pdf

View attachment 415293

Thank you for the comments. I believe I was getting confused now as I was mistaking the PCV tube from the air intake. This is the incorrect PCV tube that I need to connect to. I'll follow up more later when I have my can installed, as I just received it yesterday.

 

[BlaineBug]

Here is how a $25.68 (with tax) oil catch can looks. I removed one of the plastic push pins that secures the plastic cowl cover to the sheet metal below, and secured the bracket there above the driver side valve cover. I had to hammer the catch can bracket flat. The only difference between the 2019+ Silverado catch can is that the bracket is like this one, and the pre-2019 Silverado catch can bracket has a different angle to it. The 2019+ variety is a bit cheaper considering that it's identical with the exception of the bracket.

I'm not sure where they had intended you to mount it, but they were a bit stingy with their hoses (obviously!) so this was the best spot I could come up with that also would not be in the way.

 

[donjetman]

I mounted my $25 catch can at the hood gas spring lower mount, between the power brake booster and the driverside valve cover.
No regrets.

 

[BlaineBug]

I mounted my $25 catch can at the hood gas spring lower mount, between the power brake booster and the driverside valve cover.
No regrets.
View attachment 415420

How are your plastic fittings holding up? Mine has plastic as well (less than ideal) but cheap = cheap. I just did it for fun, really.

 

[donjetman]

How are your plastic fittings holding up? Mine has plastic as well (less than ideal) but cheap = cheap. I just did it for fun, really.

5 years and no problem

 

[Roger906]

I have the same one as you, and I haven't had any oil/water collected in the last 2 oil changes I've done. I pulled it apart, and it wasn't the ball-valve seized. It was just empty.

When I first installed it, I'd get water/sludge in there. I wonder if it's something that's a non-issue in the warm months, but will return during the cold winter weather.

Edit: the bracket is straight garbage, but I've been too lazy to improve it.

Absolutely more condensate collected in cold weather

 

[BlaineBug]

Can someone confirm which PCV fitting (the one on the driver side midway intake manifold or the one near the throttle body) is the IN and the OUT?

 

[Scrappycrow]

They are trying to sale something you don't need on the (clean) passenger side.

PVC system air flow on the passenger side is clean filtered air via plumbing and flow "INTO" the passenger side valve cover. No catch can needed on that side.

That's certainly true for the overwhelming majority of street operation, but at high-load or full-throttle operation when there's the combination of low/no vacuum and increased blowby, crankcase vapor will flow out of that intake side. Whether it's worth it to install a catch can on that side will depend on if you see evidence of anything other than a minor amount of oil in that tube or the intake tract after a stint of high-load or full-throttle operation.