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beerpilot

2018 Sierra, How Many PCVs?

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Just got a new 2018 Sierra with more bells and whistles than I've ever seen in a truck before.  Sure learning a lot on these forums.

 

The catch can thing has my interest, I never even knew that was a problem, never had a direct injection vehicle before.

 

I'm looking under the hood on this thing and although it is difficult to see much it looks like there are two PCV valves, assuming that's what I think I'm seeing.  They are right up front of the engine, one each side, with short tubes going into the intake air plenum.  See attached photo of the front left side of the engine.

 

So question #1, are two PCVs what I am seeing?

 

Question #2, if so then I need either two catch cans, or one that does double duty, right?

 

I'm a little confident that the answers to my questions will be yes (still appreciate confirmation though) and if so this will be a plumbing nightmare.  This truck has the eAssist which means the only open space for a can is the front left corner where the battery used to be, on eAssist it's up in the back right corner of the engine bay.  And, there is no room at all left in that part of the engine bay, it is packed.

 

So I guess question #3 is, anyone come up with a creative way of solving this problem, besides hoses all across the top of the engine?

 

Thanks in advance for responses.

Left-PCV.jpg

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There are two options with catch cans; 1 port or 2 port. The single port will pull from just the crankcase as what is typical. The 2 port version taps into the clean air side which is what the two lines are up on both sides of the plenum. The clean air version is for low vacuum events such as full throttle or long hill climbs while towing. You’ll have positive crankcase pressure during those times without sufficient intake vacuum to evacuate the crankcase. In those situations crankcase vapor flows out and into the clean air side of the air intake which can pull in oil mist as well. The 2 port catch cans tap into that.

The can can be mounted on the brake booster which will also keep the can warm since it’s so close to the exhaust manifold. This will also help evaporate the water that collects in the can so it won’t fill up as fast.

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1 hour ago, beerpilot said:

Just got a new 2018 Sierra with more bells and whistles than I've ever seen in a truck before.  Sure learning a lot on these forums.

So I guess question #3 is, anyone come up with a creative way of solving this problem, besides hoses all across the top of the engine?

 

The best solution I have found is to have my truck serviced on regular intervals.  If I do,  the engine will outlast my needs as well as the needs of  subsequent owners. The use of catch cans etc. are fine if they make you feel better about your truck.  Not using one doesn't mean impending doom for your engine or that you are being negligent.  

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Thanks John for a little education, the last time I cared about a PCV was on an old car and there was only the one on the valve cover.

 

The second post (from British Columbia, sorry no name), are you saying that the intake valve buildup isn't the problem that people say it is, or when doing regular maintenance the mechanic is doing something to take care of that problem for you?  I'm not challenging your statement, this new stuff for me, I'm learning.

 

Thanks both of you for your time and responses.

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