Need PCV system info
Thread Starter
Instructor
Joined: Dec 2005
Posts: 100
Likes: 0
From: Austin, TX
Need PCV system info
I have a '99 C5, and the former owner of the car blocked off the PCV system. He capped off the passanger side valve cover, and re-routed the other lines. Now after I run my car hard, the pressure in the crankcause causes oil to leak out the crank seal.
Can someone please explain, or better yet, post a diagram of how the factory PCV system is supposed to be routed? I need to reverse this BS hack job immediately.
Can someone please explain, or better yet, post a diagram of how the factory PCV system is supposed to be routed? I need to reverse this BS hack job immediately.
Team Owner
Joined: Mar 1999
Posts: 22,025
Likes: 192
From: At the beach in little Rhody
This is a photo from my 02. There is a second PCV suction connection at the back of the driver's side valve cover and they "T" behind the intake to the PCV valve and then into the intake. Fresh filtered air is picked up by the TB hose. Hope this helps.
Thread Starter
Instructor
Joined: Dec 2005
Posts: 100
Likes: 0
From: Austin, TX
Great info. Any idea how big the rubber hoses are? I'm debating between going to Autozone and buying some hose to rig the PCV system back up, or just calling up Fred Beans and ordering the factory hoses. Thanks for your help!
Safety Car
Joined: Jan 2001
Posts: 3,879
Likes: 3
From: Hobart, WI
GM tried many different shemes with the PCV. The state of the art in 04 had no vent on driver's side cover and no rear vent on pass side. The LS6 valley cover vents to intake and the front pass side goes to TB. Trying to reconstruct the pervious systems is hopeless.
Melting Slicks
Joined: Jan 2003
Posts: 3,251
Likes: 4
For the time being you can put a breather on the oil fill tube. This way pressure won't back up.
I think the only ones who cap the valve cover port are those who have used a blower or turbo. I wonder what the real Hx is of this car and if the main seals are blown?
I think the only ones who cap the valve cover port are those who have used a blower or turbo. I wonder what the real Hx is of this car and if the main seals are blown?
Thread Starter
Instructor
Joined: Dec 2005
Posts: 100
Likes: 0
From: Austin, TX
Originally Posted by IM QUIKR
For the time being you can put a breather on the oil fill tube. This way pressure won't back up.
I think the only ones who cap the valve cover port are those who have used a blower or turbo. I wonder what the real Hx is of this car and if the main seals are blown?
I think the only ones who cap the valve cover port are those who have used a blower or turbo. I wonder what the real Hx is of this car and if the main seals are blown?
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Melting Slicks
Joined: Jan 2003
Posts: 3,251
Likes: 4
Try something. Start the engine and pull out the oil dip stick. Tell us if you feel a puffing coming from the tube. A compression check might be a good idea. NA shouldn't generate positive crankcase pressure really unless there is blowby from worn rings. puffing like a freight train from the dip stick tube is a quick way to see if your rings are intact.
How did the PO route the other PCV hoses?
How did the PO route the other PCV hoses?
Thread Starter
Instructor
Joined: Dec 2005
Posts: 100
Likes: 0
From: Austin, TX
Originally Posted by IM QUIKR
Try something. Start the engine and pull out the oil dip stick. Tell us if you feel a puffing coming from the tube. A compression check might be a good idea. NA shouldn't generate positive crankcase pressure really unless there is blowby from worn rings. puffing like a freight train from the dip stick tube is a quick way to see if your rings are intact.
How did the PO route the other PCV hoses?
How did the PO route the other PCV hoses?
IMHO, some blow-by is normal on an n/a motor when you're running the snot out of it for extended durations of time. If not, the factory would have no need to vent the crankcase in the first place. Also, if n/a motors didn't have some blow-by, they'd never pick up power with a vacuum pump, which is almost never the case.
Right now, the PCV system is completely blocked off. All the vent tubes on both valve covers are capped. There's a bolt jammed into the "T" fitting on the back of the intake, and there's a U-shaped nylon hose connecting the nipples on the throttle-body and the front of the intake manifold.
I guess having to reverse bogus "mods" are what you get for being too poor to afford a new Vette
Last edited by FRC Shopper; Sep 4, 2006 at 12:20 AM.
Melting Slicks
Joined: Mar 2003
Posts: 2,743
Likes: 9
From: FL
Cruise-In VI Veteran
I've had my valley cover leak and out where the knock sensors are when the PCV hose kinked up. (acting like it was blocked off) Currently, I'm running a stock type PCV setup with an oil catch can. It seems to work great. Eventually I plan on swapping to the LS6 valley cover. But right now, it's ok.
I would definitely put a breather on it or make something for the PCV. Don't leave it plugged up.
I would definitely put a breather on it or make something for the PCV. Don't leave it plugged up.
Le Mans Master
Joined: Aug 2002
Posts: 8,472
Likes: 38
From: Houston TX
St. Jude Donor '11
If you're pretty much starting from scratch I would do this:
Run a new 3/8" hose from the rear of the drivers side valve cover, behind the intake to a tee. At the 90 degree part of the tee tie in the passenger side rear valve cover vent. On the other part of the tee go to the PCV valve, or better yet, through a catch can (Campbell Hausfeld air compressor separator) and then to the PCV valve, then to the throttle body. Cap off the port on the throttle body going to the front passenger valve cover vent and put a small K&N breather in it's place (P/N 62-1000 or 62-1320).
HTH
Run a new 3/8" hose from the rear of the drivers side valve cover, behind the intake to a tee. At the 90 degree part of the tee tie in the passenger side rear valve cover vent. On the other part of the tee go to the PCV valve, or better yet, through a catch can (Campbell Hausfeld air compressor separator) and then to the PCV valve, then to the throttle body. Cap off the port on the throttle body going to the front passenger valve cover vent and put a small K&N breather in it's place (P/N 62-1000 or 62-1320).
HTH
Race Director
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From: Redsox, Pats, Celts & Bruins !!! Redsox Nation !!!
St. Jude Donor '06-'07-'08-'09-'10-'11-'12
The worse part is if you go through GM for the rubber parts it will cost you around $70 bucks. The PCV rubber holder is not sold seperatly. They make you buy the whole hose kit. Which is 
My PCV holder is leaking and making a suction noise.
That was the price I was quoted from Beans.
If you find another way to get a PCV holder, please post it.
Thanks
My PCV holder is leaking and making a suction noise.That was the price I was quoted from Beans.
If you find another way to get a PCV holder, please post it.
Thanks
Safety Car
Joined: Jan 2001
Posts: 3,879
Likes: 3
From: Hobart, WI
Originally Posted by screw991le
The worse part is if you go through GM for the rubber parts it will cost you around $70 bucks. The PCV rubber holder is not sold seperatly. They make you buy the whole hose kit. Which is My PCV holder is leaking and making a suction noise.
That was the price I was quoted from Beans.
If you find another way to get a PCV holder, please post it.
Thanks
My PCV holder is leaking and making a suction noise.That was the price I was quoted from Beans.
If you find another way to get a PCV holder, please post it.
Thanks
Safety Car
Joined: Jan 2001
Posts: 3,879
Likes: 3
From: Hobart, WI
Originally Posted by nmbis2k
would the 2004+ system be a reasonable upgrade for earlier cars??
would the upgrade use the existing hardparts on the engine?
thanks....
would the upgrade use the existing hardparts on the engine?
thanks....
If you do the above you will be like late LS1/6/2s. It will require the plug for the driver's side and a LS6 valley cover to provide the connection under the TB.
Last edited by see5; Sep 8, 2006 at 06:53 AM.
Instructor
Joined: Jun 2006
Posts: 220
Likes: 1
From: East Windsor NJ
Here is a link to how to convert to the Valley Cover version on the LS6.
http://www.ls1howto.com/index.php?article=18
I also recommend the "Home Depot" catch can mod, I researched it extensively and found that all LSx motors injest oil on hard driving through the PCV system. See my post here on the Z forum: http://www.z06vette.com/forums/showthread.php?t=101925
There is always some blowby and it will cause pressure to build in the crankcase. Older motors had breathers, the EPA decided that was bad and voila PCV systems that redirect the positive pressure in the crankcase back to the intake. The problem on the LSx motors and some imports is that during spirited driving the motor will pass excessive oil vapor due to the design. You can either let your motor eat it, separate it out before hand, or install a breather cap on the oil filler neck.
http://www.ls1howto.com/index.php?article=18
I also recommend the "Home Depot" catch can mod, I researched it extensively and found that all LSx motors injest oil on hard driving through the PCV system. See my post here on the Z forum: http://www.z06vette.com/forums/showthread.php?t=101925
There is always some blowby and it will cause pressure to build in the crankcase. Older motors had breathers, the EPA decided that was bad and voila PCV systems that redirect the positive pressure in the crankcase back to the intake. The problem on the LSx motors and some imports is that during spirited driving the motor will pass excessive oil vapor due to the design. You can either let your motor eat it, separate it out before hand, or install a breather cap on the oil filler neck.
Race Director
Joined: Sep 2004
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From: Redsox, Pats, Celts & Bruins !!! Redsox Nation !!!
St. Jude Donor '06-'07-'08-'09-'10-'11-'12
Originally Posted by see5
So why re-create the obsolete system? It has lots of hoses and valves and does not work. The 04 system is much simpler, cheaper and may even work better?
Instructor
Joined: Jun 2006
Posts: 220
Likes: 1
From: East Windsor NJ
The LS6 / LS2 system has the pcv system routing out of the valley cover rather than the valve cover. It was supposed to stop this problem through the use of baffling and the new location. Believe it or not the LS2 does not even seem to have a pcv valve at all, just a hose between the valley cover and the throttle body.
Race Director
Joined: Apr 2001
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From: Saint Augustine, FL
Mid-TN Events Coordinator
St. Jude Donor '03-'04-'05-'06-'07-'08-'09-'10-'11-'12-'13-'14-'15-'16
Originally Posted by FRC Shopper
I have a '99 C5, and the former owner of the car blocked off the PCV system. He capped off the passanger side valve cover, and re-routed the other lines. Now after I run my car hard, the pressure in the crankcause causes oil to leak out the crank seal.
Can someone please explain, or better yet, post a diagram of how the factory PCV system is supposed to be routed? I need to reverse this BS hack job immediately.
Can someone please explain, or better yet, post a diagram of how the factory PCV system is supposed to be routed? I need to reverse this BS hack job immediately.
I have to agree with one of the previous posters... Remove the dipstick and make sure it's not puffing. Just because you ran a fast time down the track doesn't mean there's not a problem.
