GMC Truck Forum banner

1 - 17 of 17 Posts

·
04 GMC Sierra 2500HD
Joined
·
359 Posts
Discussion Starter #1
Hey guys,

I posted a while ago about deleting the PCV and venting to atmosphere in my LQ4 - 408 Stroker. My question is when you demo the PCV vent line back to the tank should you leave that as a vent? or just cap that line? Curious if it is dangerous to cap that line, but at the same time the tank is already vented so I don't see it being an issue.

Any help is appreciated, thank you!
 

·
Registered
Joined
·
669 Posts
Are you asking about PCV or EVAP? you mention a tank and that makes me think of the fuel tank which is part of the EVAP system. PCV is from the valve covers. Honestly I am not sure the benefit of removing either... What are you hoping to gain?
 

·
04 GMC Sierra 2500HD
Joined
·
359 Posts
Discussion Starter #3
The PCV not the evap. There is a line from the PCV valve that follows the fuel line all the way back to the gas tank.

I’m not hoping to gain anything, the motor now has an aftermarket intake so the stock system will no longer work.
So the decision to switch to a catch can was made.
 

·
Registered
Joined
·
2,255 Posts
PCV is positive crankcase ventilation. PCV valve is in the driver valve cover and goes straight to the manifold.

Your taking about the EVAP Purge.
 

·
Toxic Masculinity
Joined
·
3,714 Posts
Yeah that's the EVAP bro :oops:

You disable that and it makes it hard to fill the fuel tank (no vent)
 

·
04 GMC Sierra 2500HD
Joined
·
359 Posts
Discussion Starter #6
Ahaha you guys are 110% correct... that definitely solves my confusion as to why I couldn’t understand the vent line ahahahaha. Whoops!
 

·
04 GMC Sierra 2500HD
Joined
·
359 Posts
Discussion Starter #7
Definitely feel stupid, but I appreciate everyone trying to help.
 

·
Registered
Joined
·
2,802 Posts
Yeah that's the EVAP bro :oops:

You disable that and it makes it hard to fill the fuel tank (no vent)
Mine has been deleted for years with no filling issues. I also run 2 vents on my tank

Sent from my SM-G930W8 using Tapatalk
 

·
04 GMC Sierra 2500HD
Joined
·
359 Posts
Discussion Starter #9
Did you vent w/ a filter at the end or just let it vent to atmosphere under the truck? Not sure if I want to delete it or just re-route the line in to one of the vacuum ports on the new intake
 

·
Registered
Joined
·
2,802 Posts
I have my factory vent that goes to the filler neck, I plugged my evap at the tank and added another vent off the feed line(I run all braided). I ran the second vent as high as I could looped a bunch of times with no filter, I run a -10 braided hose for it and just havent gotten a filter that fits yet

Sent from my SM-G930W8 using Tapatalk
 

·
04 GMC Sierra 2500HD
Joined
·
359 Posts
Discussion Starter #11
Hmm, I like that idea a lot.
 

·
Registered
Joined
·
2,255 Posts
The only issue with capping it will be if you already have canister issue, and a tank that’s hard to fill.

That line is only to vent the gas smell.
 

·
04 GMC Sierra 2500HD
Joined
·
359 Posts
Discussion Starter #13
Yeah, I don't plan on just capping it at the tank now that I am clear on what it is:LOL:.

Now it is jut the debate of running a new vent at the tank and venting under the bed or if I want to reroute the evap solenoid and some how tie it in with hose/barbed fittings on the holley high ram.
 

·
Registered
Joined
·
669 Posts
If you don't mind my asking, what is the advantage you are looking to accomplish by bypassing it? I can't see how you would gain any performance advantage, unless you have a vacuum leak in the lines...
 

·
04 GMC Sierra 2500HD
Joined
·
359 Posts
Discussion Starter #15
Yes, absolutely. I am not doing it to gain performance, The Truck has a new motor and paired with that will be an aftermarket intake. I am being forced to either remove it or Get creative and plumb in the factory evap system.
 

·
Registered
Joined
·
669 Posts
That makes sense. In which case I assume you are going to tune the codes out of the PCM? You can just block off the line that runs back to the charcoal canister mounted next to the tank. It is only opened when the engine is running to "empty" the charcoal canister of vapor.
 

·
04 GMC Sierra 2500HD
Joined
·
359 Posts
Discussion Starter #17
Yeah they will be tuned out, it they are not already!
 
1 - 17 of 17 Posts
Top