My EVAP system ran incorrectly??
Thread Starter
Burning Brakes
Joined: May 2008
Posts: 1,043
Likes: 1
From: Houston TX
My EVAP system ran incorrectly??
Posted up pics of my new tb install and another member pointed out that my vacuum system, evap, whatever you call it isnt correct. Is the bellows hes referring to in the quote below the vacuum line that goes into the accordian looking tubing right in front of the throttle body? If so I can follow it to the hose that goes into the valve cover and cap off both of those. Also is he correct in telling me to cap both of those off? Thanks guys! 
hey sunsetstroker, i see you have a filter in the oil cap, since you have the fresh air inlet there you should get rid of that line thats coming from the bellows. cap it at the valve cover and the bellows, in that setup, you could be pulling air threw the valve cover increasing your oil burning and it also bypasses your maf up to a certain point.
-carl
hey sunsetstroker, i see you have a filter in the oil cap, since you have the fresh air inlet there you should get rid of that line thats coming from the bellows. cap it at the valve cover and the bellows, in that setup, you could be pulling air threw the valve cover increasing your oil burning and it also bypasses your maf up to a certain point.
-carl
Melting Slicks
Joined: May 2004
Posts: 3,017
Likes: 2
Its your PCV system that your modifying. The PCV system routes clean filtered and metered air into the crankcase via the port on the accordian hose, and pulls crankcase vapors out via the valley cover port to the port behind the TB. Purpose of the clean air is to help remove the nasty byproducts of combustion and keep your oil cleaner. You have intercepted the oil vapors with the catch can, but are allowing unmetered air in through the filter on top of the filler cap.
Either ditch the filter and go back to a stock cap, Keeping everything else plumbed the way it is ( about 90% effective at trapping oil) or ditch the filter and run a breather can like in this thread:http://forums.corvetteforum.com/c6-t...installed.html
but are allowing unmetered air in through the filter on top of the filler cap. Either ditch the filter and go back to a stock cap, Keeping everything else plumbed the way it is ( about 90% effective at trapping oil) or ditch the filter and run a breather can like in this thread:http://forums.corvetteforum.com/c6-t...installed.html
Last edited by nwc6; Jun 15, 2009 at 10:44 PM.
Race Director
Joined: Mar 2005
Posts: 10,399
Likes: 26
From: Austin Texas
The Positive Crankcase Ventilation (PCV) system is designed to pull combustion pressure from the crankcase and to route the oil and fumes to the combustion chambers rather than pollute the outside air. LS2 and LS3 engines have 2 lines for the PCV, one from the valley cover to behind the throttle body to remove pressure from the crankcase and one from the passenger side valve cover to before the throttle body for "make-up" air.
The filter on the valve cover violates Federal Emmisions laws and won't legally pass the visual part of most States inspections.
The filter on the valve cover violates Federal Emmisions laws and won't legally pass the visual part of most States inspections.
Thread Starter
Burning Brakes
Joined: May 2008
Posts: 1,043
Likes: 1
From: Houston TX
Its your PCV system that your modifying. The PCV system routes clean filtered and metered air into the crankcase via the port on the accordian hose, and pulls crankcase vapors out via the valley cover port to the port behind the TB. Purpose of the clean air is to help remove the nasty byproducts of combustion and keep your oil cleaner. You have intercepted the oil vapors with the catch can, but are allowing unmetered air in through the filter on top of the filler cap.
Either ditch the filter and go back to a stock cap, Keeping everything else plumbed the way it is ( about 90% effective at trapping oil) or ditch the filter and run a breather can like in this thread:http://forums.corvetteforum.com/c6-t...installed.html
but are allowing unmetered air in through the filter on top of the filler cap. Either ditch the filter and go back to a stock cap, Keeping everything else plumbed the way it is ( about 90% effective at trapping oil) or ditch the filter and run a breather can like in this thread:http://forums.corvetteforum.com/c6-t...installed.html
Thread Starter
Burning Brakes
Joined: May 2008
Posts: 1,043
Likes: 1
From: Houston TX
The Positive Crankcase Ventilation (PCV) system is designed to pull combustion pressure from the crankcase and to route the oil and fumes to the combustion chambers rather than pollute the outside air. LS2 and LS3 engines have 2 lines for the PCV, one from the valley cover to behind the throttle body to remove pressure from the crankcase and one from the passenger side valve cover to before the throttle body for "make-up" air.
The filter on the valve cover violates Federal Emmisions laws and won't legally pass the visual part of most States inspections.
The filter on the valve cover violates Federal Emmisions laws and won't legally pass the visual part of most States inspections.
Melting Slicks
Joined: May 2004
Posts: 3,017
Likes: 2
Fixed the link. Normally the only time you see high crankcase pressures is with FI..N/A motors should not have a lot of blow by. If you are concerned with too much crankcase pressure, then get rid of the catch can and the filter on the filler cap and utilize a breather can. Cartek sells them, as does one of the big online catalog parts places..
Safety Car
Joined: Feb 2008
Posts: 3,712
Likes: 3
From: TEXOMA
St. Jude Donor '08-'09
sry for not getting back to you quicker,
do what everyone is saying, in either get rid of that filter on the cap, or disconnect the line that goest to the bellows and top valve cover(next to the filter cap) and cap them both
i have the filter in the cap, and some silicone couplers, and capped the valve cover line.
see...
the way i have mine setup (like several others), oil can't get back in threw the intake side, and the catch can, does its job between the lower valley cover and the fitting on the intake
-carl
do what everyone is saying, in either get rid of that filter on the cap, or disconnect the line that goest to the bellows and top valve cover(next to the filter cap) and cap them both
i have the filter in the cap, and some silicone couplers, and capped the valve cover line.
see...
the way i have mine setup (like several others), oil can't get back in threw the intake side, and the catch can, does its job between the lower valley cover and the fitting on the intake
-carl
Last edited by carlrx7; Jun 16, 2009 at 10:14 AM.
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Melting Slicks
Joined: May 2004
Posts: 3,017
Likes: 2
sry for not getting back to you quicker,
do what everyone is saying, in either get rid of that filter on the cap, or disconnect the line that goest to the bellows and top valve cover(next to the filter cap) and cap them both
i have the filter in the cap, and some silicone couplers, and capped the valve cover line.
see...
the way i have mine setup (like several others), oil can't get back in threw the intake side, and the catch can, does its job between the lower valley cover and the fitting on the intake.
-carl
do what everyone is saying, in either get rid of that filter on the cap, or disconnect the line that goest to the bellows and top valve cover(next to the filter cap) and cap them both
i have the filter in the cap, and some silicone couplers, and capped the valve cover line.
see...
the way i have mine setup (like several others), oil can't get back in threw the intake side, and the catch can, does its job between the lower valley cover and the fitting on the intake.
-carl
See this post:http://forums.corvetteforum.com/c6-t...t-on-tune.html
Last edited by nwc6; Jun 16, 2009 at 12:12 PM.
Safety Car
Joined: Feb 2008
Posts: 3,712
Likes: 3
From: TEXOMA
St. Jude Donor '08-'09
If so that is the path of oil ingestion. The hose on the valve cover is to supply clean air into the crankcase. In this case there is un metered air entering the engine.
See this post:http://forums.corvetteforum.com/c6-t...t-on-tune.html
See this post:http://forums.corvetteforum.com/c6-t...t-on-tune.html
Thread Starter
Burning Brakes
Joined: May 2008
Posts: 1,043
Likes: 1
From: Houston TX
sry for not getting back to you quicker,
do what everyone is saying, in either get rid of that filter on the cap, or disconnect the line that goest to the bellows and top valve cover(next to the filter cap) and cap them both
i have the filter in the cap, and some silicone couplers, and capped the valve cover line.
see...
the way i have mine setup (like several others), oil can't get back in threw the intake side, and the catch can, does its job between the lower valley cover and the fitting on the intake
-carl
do what everyone is saying, in either get rid of that filter on the cap, or disconnect the line that goest to the bellows and top valve cover(next to the filter cap) and cap them both
i have the filter in the cap, and some silicone couplers, and capped the valve cover line.
see...
the way i have mine setup (like several others), oil can't get back in threw the intake side, and the catch can, does its job between the lower valley cover and the fitting on the intake
-carl
Melting Slicks
Joined: May 2004
Posts: 3,017
Likes: 2
As I said in an earlier post, if you or your engine builder think there is too much crankcase pressure then go the breather can route.
Here is another long discussion of the PCV system:http://forums.corvetteforum.com/c6-t...-question.html
Thread Starter
Burning Brakes
Joined: May 2008
Posts: 1,043
Likes: 1
From: Houston TX
Its your PCV system that your modifying. The PCV system routes clean filtered and metered air into the crankcase via the port on the accordian hose, and pulls crankcase vapors out via the valley cover port to the port behind the TB. Purpose of the clean air is to help remove the nasty byproducts of combustion and keep your oil cleaner. You have intercepted the oil vapors with the catch can, but are allowing unmetered air in through the filter on top of the filler cap.
Either ditch the filter and go back to a stock cap, Keeping everything else plumbed the way it is ( about 90% effective at trapping oil) or ditch the filter and run a breather can like in this thread:http://forums.corvetteforum.com/c6-t...installed.html
but are allowing unmetered air in through the filter on top of the filler cap. Either ditch the filter and go back to a stock cap, Keeping everything else plumbed the way it is ( about 90% effective at trapping oil) or ditch the filter and run a breather can like in this thread:http://forums.corvetteforum.com/c6-t...installed.html
So either way you dont like the filter in the oil cap?? I guess Im just worried about too much crank case pressure. Wonder why the engine builder told me to do that? I also have a breather on the drivers side valve cover on that little 1/2 inch piece of tubing thats close to the firewall.
Melting Slicks
Joined: May 2004
Posts: 3,017
Likes: 2
So either way you dont like the filter in the oil cap?? I guess Im just worried about too much crank case pressure. Wonder why the engine builder told me to do that? I also have a breather on the drivers side valve cover on that little 1/2 inch piece of tubing thats close to the firewall.
If you don't believe me, see post #7: http://forums.corvetteforum.com/c6-t...t-on-tune.html
Get rid of the catch can because now there is no way oil can get in your intake. You will have effectively removed the entire PCV system.
Can you take a picture of the 1/2" line on the drivers side? Your builder must have run a line from the valve cover to vent that side.
Thread Starter
Burning Brakes
Joined: May 2008
Posts: 1,043
Likes: 1
From: Houston TX
[QUOTE=nwc6;1570470950]I didn't say that. If you want to run your breather caps, then cap off the hole at the accordian bellows,( probably need a silicone coupler since that hole doesn't plug well) Follow that line to the valve cover take the hose off and run a 2ft vacuum/fuel hose down along the block. Now cap the port behind the TB. For the nipple on the valley cover, do the same as you did the valve cover.
If you don't believe me, see post #7: http://forums.corvetteforum.com/c6-t...t-on-tune.html
Get rid of the catch can because now there is no way oil can get in your intake. You will have effectively removed the entire PCV system.
Can you take a picture of the 1/2" line on the drivers side? Your builder must have run a line from the valve cover to vent that side.[/QUOTE]
No, its just a little inlet coming out of the back of the valve cover that I put a little breather on. I'll take a pic tonight.
If you don't believe me, see post #7: http://forums.corvetteforum.com/c6-t...t-on-tune.html
Get rid of the catch can because now there is no way oil can get in your intake. You will have effectively removed the entire PCV system.
Can you take a picture of the 1/2" line on the drivers side? Your builder must have run a line from the valve cover to vent that side.[/QUOTE]
No, its just a little inlet coming out of the back of the valve cover that I put a little breather on. I'll take a pic tonight.
Safety Car
Joined: Feb 2008
Posts: 3,712
Likes: 3
From: TEXOMA
St. Jude Donor '08-'09
i see what your saying,, sorry, i read your post wrong.
yes, on my system the fresh air source for my pcv system is UNmetered, but thats what a PCV valve is for,
i know this way, it works, 0 oil in manifold and on TB after 2000 miles.
yall do what you like
Thread Starter
Burning Brakes
Joined: May 2008
Posts: 1,043
Likes: 1
From: Houston TX
So should I remove the filters on each valve cover or remove the bellows and cap the inlet that goes to the bellows on the pass side valve cover? I need to know for sure as Texas Speed told me to vent both valve covers.
