Zlow28

iTrader: (11)

While gassing up last night, i noticed a mean vacuum leak. Tonight i had a chance to take a look at the engine bay and i found a huge hole in the pcv hose.
The blue one to be exact.


My question is, should i replace it or temporarily fix it with electrical tape?

Reason is im doing a ls6 intake swap soon and im also switching to a ls6 valley cover. I already have most of the parts, i just need to buy new knock sensors and harness. So if i do the ls6 valley cover, will i be removing that hose? or just the crossover hose?

I would hate to replace the hose only for me to remove it in a week or two.

Question 2, will a vacuum cause popping/backfire sounds and misfires in idle? Ive had minor vacuum problems before but ive never heard popping sounds. When coming to a stop in neutral or the clutch pressed in, rpms rise to about 2100. PCM only shows vacuum related codes.

Any input welcomed, thanks.

AmarilloWS6

iTrader: (3)

I'd fix it with electrical tape for the time being. With the ls6 valley cover you will be throwing away the entire crap ls1 PCV system, the entire system will now be built into the valley cover unless you bought a pre 04 ls6 valley cover, where you'll then need to use an external PCV valve. This is what it will look like in a nut shell, really cleans up the engine bay, I did this to my car last year.

Zlow28

iTrader: (11)

Thanks for the quick response. I didnt know it would clean it up that much, your car looks clean. Ill eventually add a catch can too, but for know im just going to do ls6 valley cover and tape up the hose.

AmarilloWS6

iTrader: (3)

With the ls6 valley cover you won't need the hose anymore, you'll just have the valley cover, and a u-shaped hose going from the valley cover to the intake manifold, where my two catch can hoses are. My catch can doesn't collect much in it most of the time because the updated ls6 valley cover. My intake's dry as a bone and what little mist makes it past the valley cover gets sucked into the catch can before it enters the intake, I've been very pleased with the results. Even though my engines covered by fuel rail covers I still like knowing how cleaned up it is underneath I'm taking the EVAP crap off the other side before my next tune too.

Zlow28

iTrader: (11)

for the u-shaped hose, can i reuse part of my current one, or will i have to build a new one from scratch?

AmarilloWS6

iTrader: (3)

If you have a 2004 ls6 Valley Cover this is the hose you'll need

If you have a pre 04 ls6 Valley Cover you'll need this one, notice how there's a PCV valve in that line.

If you bought the valley cover new from a vendor I'm almost 100% certain you received a 2004 cover. The last time I tried to bend hose into that u-shape for a friends car it just kinked and cause the vacuum to cut off so I think you might have to buy the hose from GM, eBay, etc. I believe it's $10? The OEM hose is obviously formed that way so it won't kink.

AmarilloWS6

iTrader: (3)

12577927 This is the part number for the 2004 ls6 valley cover
12594779 This is the part number for the valve-less hose for the 2004 valley cover
12568011 This is the part number for the cap to plug the hole in the back of the driver side valve cover.
You will also need a little cap from an auto parts store to cap off the little nipple on the passenger side valve cover. You'll notice in my photo my caps red, that cap came on my valley cover so I just re-used it to cap that off.

Zlow28

iTrader: (11)

thanks for the pics. I bought the 04+ valley cover. So ill just need the hose, valley cover plug, and nipple plug right?

Trying to get all my parts ready to do the swap in one day.

AmarilloWS6

iTrader: (3)

For the complete swap you'll need the valley cover, the plug for the driver side valve cover, a plug for nipple on the passenger side valve cover, the hose connecting the valley cover nipple to the ls6 intake, AND you'll need to either buy ls6 coolant lines and block offs for the rear, or try to heat and bend your ls1 coolant lines around all of the protrusions on the ls6 valley cover. Personally, I just took the easy way out and bought the ls6 coolant lines with the block-offs in the rear and I haven't had ANY heating issues in this 100+ degree weather where I live. If you use the ls6 coolant lines with the ls6 valley cover and ls6 intake you won't have to shave the bottom of the intake either.

Zlow28

iTrader: (11)

right now, i already have the ls6 valley cover, ls6 intake, extra OPSU, egr and air block off plates, throttle body gasket, and intake manifold seals/gaskets.

For the coolant lines, im planning on grinding down the fins on the ls6 intake to make the ls1 lines fit without further modifications.

Im waiting to order the extra 99+ knock sensors and sensor harness, and the hoses and plugs to finish up the vacuum route.

AmarilloWS6

iTrader: (3)

If you're keeping your ls1 coolant lines you're going to have to heat up the tubes and bend them out of the way of the nipple coming out of the ls6 valley cover even if you cut the fins off the bottom of the intake. On top of that you have to bend them around each provision pooping up everywhere on the valley cover where the oil separator/PCV are screwed into the bottom just like this..

You'll have to put some extra tape on the knock sensor harness if you keep the ls1 lines as the line will be on the wire. I've thought about putting my ls1 lines back on and doing this but my ls6 lines haven't caused any harm so I just haven't wanted to do the swap again lol

sjsingle1

iTrader: (1)

that pic looks familiar......

Zlow28

iTrader: (11)

I didn't know that about the coolant lines. What did you use to bend them?

AmarilloWS6

iTrader: (3)

Haha, I just google imaged to find that photo.
I didn't bend my ls1 lines, I just bought the ls6 lines with the block offs in the rear, but I've read where people use a torch to heat it up and a block of wood and hammer to bend.

Zlow28

iTrader: (11)

Im gonna try and bend the lines and take it slow to not mess them up. I already have a heat gun, so thatll save me some cash.

AmarilloWS6

iTrader: (3)

It's worth a shot since you already have them. Probably provide a little better cooling too.

Zlow28

iTrader: (11)

Ill post here when i get them done to see how it goes. Thanks for the help again.

AmarilloWS6

iTrader: (3)

Anytime buddy, let us know how it goes!

SoonerBrad88

iTrader: (15)

I haven't heard of this mod. What's the benefit?

Zlow28

iTrader: (11)

the ls6 valley cover will run a more efficient pcv system and will clean up your engine bay. A lot of people have notice less oil consumption with the ls6 valley cover too. Especially if you add a catch can too.