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N/a 5.3. Trying to figure out the PCV routing. Will these valve covers work or do I need the passenger valve cover that has two hookups? Drivers side of the TB Back side of drivers valve cover All that’s connected so far.
Throttle body to passenger side valve cover is the fresh air source. You should go from driver side back valve cover to vaccum source on intake. You might consider running a baffled catch can inline from pcv in the rear of the driver side valve cover to your vaccum source. It will keep the internal engine cleaner and help fight spark knock from oil in the fresh air after the throttle body.
Throttle body to passenger side valve cover is the fresh air source. You should go from driver side back valve cover to vaccum source on intake. You might consider running a baffled catch can inline from pcv in the rear of the driver side valve cover to your vaccum source. It will keep the internal engine cleaner and help fight spark knock from oil in the fresh air after the throttle body.
do you mean the connection on the drivers side of the TB should go to the pass side valve cover?
Not sure if you can tell from the last pic but I’ve got the pass side valve cover going to the pass side of the TB. Also it’s an ls6 Intake-i don’t think there are any Vacuum sources on the intake that were open. Valley cover is a reg 5.3 though.
The first picture looks like your EVAP hookup for the tank. I could be wrong though, but that's where it is on my FAST. Should be a click on for the EVAP line, not PCV. The vacuum for the PCV comes from the valley cover on the passenger side just behind the TB, and hooks to the passenger side of the intake, that's the vacuum "in". Fresh air should be routed from the hookups on the throttle body (aka + pressure source, not vacuum) for fresh air ventilation, or air "out". The stock line for fresh air go to both valve covers, then the TB on a junction/t style. I don't remember which way it routes, but iirc, it goes from the drivers side around the back, into the passenger side and to the TB on passenger side.
I know I have a bit of a different setup here, but you can see the EVAP can hooked up on D/S, the fresh air outlet on TB as well as fresh air hookup on P/S valve cover. Mine are capped off though, because I'm using a vacuum pump.
Also, if you note the grey electrical plug just under the throttle cable, THAT is where your PCV should hook in from the valley cover. On mine that is now the IAT sensor location lol.
Well, you might not have a connection on the valley cover. Reouting to the valve cover accomplishes the same thing though. Fresh air will still come from the TB though.
Well, you might not have a connection on the valley cover. Reouting to the valve cover accomplishes the same thing though. Fresh air will still come from the TB though.
Ya lost me. I don’t have a valley port. So the pcv hose on d/s rear valve cover doesn’t go to the d/s port in the pic?
I just did a search and apparently the drivers side port goes to a diverted valve which I won’t have on my swap. Should this be blocked off? Also trying to figure out where the pcv goes.
Last edited by sean byrd; Apr 4, 2019 at 05:22 PM.
Ya lost me. I don’t have a valley port. So the pcv hose on d/s rear valve cover doesn’t go to the d/s port in the pic?
I just did a search and apparently the drivers side port goes to a diverted valve which I won’t have on my swap. Should this be blocked off? Also trying to figure out where the pcv goes.
To break it down, it's simple. Route your fresh air from the TB, and your PCV to the intake. That's it. You just need an "in" and an "out" basically. You have 2 covers, and 2 places to make this happen. How you do it is solely up to you. You could run the P/S to the TB and route the D/S around to the intake. However you want to do it, but that is how it is designed to work. On newer LS's, it simply comes from the valley cover, and both the valve covers are the fresh air side. As long as it vents and gets fresh air, it really doesn't matter. Don't cap anything off here. The EVAP is another thing you should look at though. That hookup on the D/S is designed to allow fuel vapor to be released from the tank. Normal systems have 2 "fuel" lines, one being supply and the other being the vent. If not, a vented cap will suffice to relieve pressure, but you will have to cap that off, or use it as PCV off the D/S and cap the other one off on the P/S. Up to you brother. Also, without EVAP, you will have to turn that off in the tune if it throw a code for it.
To break it down, it's simple. Route your fresh air from the TB, and your PCV to the intake. That's it. You just need an "in" and an "out" basically. You have 2 covers, and 2 places to make this happen. How you do it is solely up to you. You could run the P/S to the TB and route the D/S around to the intake. However you want to do it, but that is how it is designed to work. On newer LS's, it simply comes from the valley cover, and both the valve covers are the fresh air side. As long as it vents and gets fresh air, it really doesn't matter. Don't cap anything off here. The EVAP is another thing you should look at though. That hookup on the D/S is designed to allow fuel vapor to be released from the tank. Normal systems have 2 "fuel" lines, one being supply and the other being the vent. If not, a vented cap will suffice to relieve pressure, but you will have to cap that off, or use it as PCV off the D/S and cap the other one off on the P/S. Up to you brother. Also, without EVAP, you will have to turn that off in the tune if it throw a code for it.
I don’t have the car in front of me and I don’t remember if that pass side is actually on the TB or the intake but if I understand what you’re saying-the TB port provides fresh air to the valve cover?
The open spot on the d/s originally goes to a diverter Valve which I don’t have-so to confirm I can cap this off?
On a car that came with the ls6 intake it would also have the ls6 valley cover so the port on the front valley goes to the pcv valve if I’m correct?-And for my instance hooking the d/s pcv to the p/s port would be the same? (Pcv on the ls6 card wasn’t in the actual valve cover from what I’m seeing.)
All the emissions codes will be turned off via HP tuners.
Last edited by sean byrd; Apr 4, 2019 at 05:53 PM.
I just did a search and apparently the drivers side port goes to a diverted valve which I won’t have on my swap. Should this be blocked off? Also trying to figure out where the pcv goes.
That port is for the evap cannister line. On the passenger side of the intake you should have another port like pictured below with the green arrow.
If not using the evap line you can use that as a vacuum port for the pcv but the other side has to be blocked off, or use the other side ( in the picture below ) and the evap line must be capped off.
To simplify it, run one valve cover to the intake and one side to the throttle body.
That port is for the evap cannister line. On the passenger side of the intake you should have another port like pictured below with the green arrow.
If not using the evap line you can use that as a vacuum port for the pcv but the other side has to be blocked off, or use the other side ( in the picture below ) and the evap line must be capped off.
To simplify it, run one valve cover to the intake and one side to the throttle body.
Here is mine, I have my clean air ( throttle body to valve cover ) going to driver's rear valve cover.
Dirty side going from front passenger to catch can, you can see the line going out of the picture by the battery, then to intake manifold.
I'm glad that 98 stepped in and clarified this. It's still the same thing I was saying, just a little more simple and with pictures lol. Yes, each valve cover will be hooked to something different. One to the TB, and one to the intake from whichever valve cover isn't hooked to the TB, however you want to route that. I don't think I could say it any simpler.
As for your EVAP, you will want to run a vented gas cap, to allow fumes to escape if pressure gets too high in the tank. This can cause problems if you don't. Like I said, should be a simple fix with a vented gas cap.
None of these things by the way have anything at all to do with emissions. PCV actually stands for Positive Crankcase Ventilation, meaning that when pressure in the crankcase is high enough, it has to vent. If it doesn't, you will blow all your seals on the block pretty much. Pressure gets through your ring gaps with every power cycle, and that builds up, quick. The fresh air side is for air to be allowed to replace the air being pulled out through vacuum (intake).
It's similar to sucking on a straw. If you don't have a fresh air side, it's like putting your thumb over the end of the straw and tying to draw air. Even though there's suction, nothing is replacing it so you will just collapse the straw before you draw anything. This I think is a good analogy for what's going on with the "fresh air" side and why it's needed.
So if you're not going to run the EVAP line, then plug that off on your intake, either side. As long as ONE valve cover is hooked to the intake in some way, it doesn't matter which side you use. So maybe hooking the D/S to the intake, where the EVAP would normally go (D/S) could work for you. Then hook the P/S valve cover to the TB, and cap that side on the intake, because you don't need a huge vacuum leak from an open tube sticking off the intake.
Sorry if I'm having difficulty making this simple. lol
Just checked and my dbw TB doesn’t have any external ports besides the coolant bypasses at the bottom.
Boy, this is becoming a project lol. There are a lot of solutions out there, you can completely delete the PCV too, which is an option. Vented oil caps, catch cans, so forth. I don't want to offend vendors here, but mightymouse has solutions available for this. Summit does as well. You could even go as far as a vacuum pump, which for all applications has lots of benefits. It's just expensive.
You need to have a fresh air supply for the PCV to work correctly. You can also just add a hookup somewhere after the filter on the intake side, and I would recommend running a catch can here so you don't have any chance of backflow.
I'm researching this for you now, looking for more solutions. It really up to you as to how to proceed, but you definitely want this working properly. Like I said earlier, if it doesn't work properly, you will have blown gaskets/seals and a big mess in your intake most likely.
Pcv routing? 
