Looking for a vacuum source for my breather can

o2sys

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Ok can't take the smell anymore, the vapors need to go somewhere.

Right now I have both the passenger and driver side of all going into a catch can with a breather filter on top.

I have also removed the internal pcv from the driver side cam cover.

The breather is working fine but the smell gets into the cabin and now also that I have a cut out for my shaker scoop at stop lights the vapors come out through it and looks like my engine is on fire.

I need some source of vacuum or anything to pull the vapors away from the car.
 

07 Boss

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Why not just use the original PCV hook up in the manifold? You'll have to close back up the system again. I'm not sure how well it's going to work without the PCV valve in there. You might want to look at putting an in-line check valve
 

o2sys

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Why not just use the original PCV hook up in the manifold? You'll have to close back up the system again. I'm not sure how well it's going to work without the PCV valve in there. You might want to look at putting an in-line check valve



Don't want to go back as I don't want to pressurize the pan.
 

07 Boss

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Don't want to go back as I don't want to pressurize the pan.

What do you mean by pressurize the pan? You have pressure in the crankcase now, that is what pushes the blow-by and fumes out of the breather. You can't draw vacuum from the engine for the PCV system without hooking the system back up. Well you can but your car will run like crap.

You can get a vacuum pump but that just seems silly.
 

06 T-RED S/C GT

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Ok can't take the smell anymore, the vapors need to go somewhere.

Right now I have both the passenger and driver side of all going into a catch can with a breather filter on top.

I have also removed the internal pcv from the driver side cam cover.

The breather is working fine but the smell gets into the cabin and now also that I have a cut out for my shaker scoop at stop lights the vapors come out through it and looks like my engine is on fire.

I need some source of vacuum or anything to pull the vapors away from the car.

Consider the Peterson fluid systems breather can, it's a completely sealed can that runs 2 lines from the valve covers that pull blow by vapors into the can rather than allowing them to vent back into the atmosphere causing the smell to get into the cabin..

Anyhow here's the link if your interested...

http://www.petersonfluidsys.com/breathercan-Coyote.html
 
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702GT

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Part of the PCV process is not just to relieve pressure on the crank case but to remove harmful/corrosive vapors from it as well. That being said, you can't just apply vacuum to both valve covers and expect results. The system was designed to pull air from the P/S valve cover to the D/S valve cover, and the intake would consume any vapor pulled, which also lead to oil consumption which is why most decide to run an oil separator. If you modify from stock, there's 2 ways you can go about it being FI.

Route 1 (For PD): Filter breather on the P/S valve cover, hose from D/S valve cover to oil separator, hose from oil separator to blower intake (If PD, that'd be your "CAI" tube).

Reason: This draws filtered fresh air into one valve cover and out the other, while the source of vacuum remains constant. If your oil separator works properly, oil vapors will be trapped and only fuel vapors will proceed to be consumed by the blower inlet.

Route 2 (For virtually any setup other than PD): Filter breather on the P/S valve cover, hose from D/S valve cover to oil separator, hose from oil separator to blower intake OR intake manifold with a check valve in-line between the manifold and oil separator.

Reason: This draws filtered fresh air into one valve cover and out the other, while the source of vacuum remains constant (unless under boost). If your oil separator works properly, oil vapors will be trapped and only fuel vapors will proceed to be consumed by the blower inlet or intake manifold. The in-line check valve, should you route to the manifold as your vacuum source, will allow air into the manifold, but close during boost, thus keeping from boosting your crank case. During that time, crank case pressure will be relieved via the valve cover filter/oil separator filter.


The engine was originally designed to consume its own crank case vapors. The only other alternative to using your intake manifold or blower inlet as a vacuum source, would be to install a small electronic or mechanical vacuum pump, but the vapor still has to go somewhere. At that point you're back-tracking technology back to the Fox body generation, smog pump equipment and EGR's. It shouldn't be that complicated. Just set up your oil separator by either method I stated above, and you shouldn't have any more issues with under hood vapors leaking to the cabin.

(Also check any of your firewall penetrations you may have done yourself or borrowed, such as for gauges, and make sure they are sealed. Shifter boot is a common source for engine smells in the cabin as well.)
 

06 T-RED S/C GT

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Part of the PCV process is not just to relieve pressure on the crank case but to remove harmful/corrosive vapors from it as well. That being said, you can't just apply vacuum to both valve covers and expect results. The system was designed to pull air from the P/S valve cover to the D/S valve cover, and the intake would consume any vapor pulled, which also lead to oil consumption which is why most decide to run an oil separator

FYI.. The Peterson breather can is the very same system used by Ford Racing for their factory Cobra Jet drag cars..

The 08-0400 breather can is our most popluar breather can. It's because of it's race proven design that Ford Motor Company decided to use a custom version of it in the factory drag Cobra Jet cars. We now offer the same can in an emission compliant design to use on your Coyote powered project. This can does not breathe to atmosphere but instead acts to catch any oil in the crank case emissions before going back into the air inlet of the motor.

That being said, I'd much rather have crankcase vapor oil trapped into a sealed container rather than getting sucked back into the crankcase through the factory PCV system with an oil separator that doesn't always prevent vapor oil from getting into the intake manifold and back into the crankcase..
 
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07 Boss

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Part of the PCV process is not just to relieve pressure on the crank case but to remove harmful/corrosive vapors from it as well. That being said, you can't just apply vacuum to both valve covers and expect results. The system was designed to pull air from the P/S valve cover to the D/S valve cover, and the intake would consume any vapor pulled, which also lead to oil consumption which is why most decide to run an oil separator. If you modify from stock, there's 2 ways you can go about it being FI.

Route 1 (For PD): Filter breather on the P/S valve cover, hose from D/S valve cover to oil separator, hose from oil separator to blower intake (If PD, that'd be your "CAI" tube).

Reason: This draws filtered fresh air into one valve cover and out the other, while the source of vacuum remains constant. If your oil separator works properly, oil vapors will be trapped and only fuel vapors will proceed to be consumed by the blower inlet.

Route 2 (For virtually any setup other than PD): Filter breather on the P/S valve cover, hose from D/S valve cover to oil separator, hose from oil separator to blower intake OR intake manifold with a check valve in-line between the manifold and oil separator.

Reason: This draws filtered fresh air into one valve cover and out the other, while the source of vacuum remains constant (unless under boost). If your oil separator works properly, oil vapors will be trapped and only fuel vapors will proceed to be consumed by the blower inlet or intake manifold. The in-line check valve, should you route to the manifold as your vacuum source, will allow air into the manifold, but close during boost, thus keeping from boosting your crank case. During that time, crank case pressure will be relieved via the valve cover filter/oil separator filter.


The engine was originally designed to consume its own crank case vapors. The only other alternative to using your intake manifold or blower inlet as a vacuum source, would be to install a small electronic or mechanical vacuum pump, but the vapor still has to go somewhere. At that point you're back-tracking technology back to the Fox body generation, smog pump equipment and EGR's. It shouldn't be that complicated. Just set up your oil separator by either method I stated above, and you shouldn't have any more issues with under hood vapors leaking to the cabin.

(Also check any of your firewall penetrations you may have done yourself or borrowed, such as for gauges, and make sure they are sealed. Shifter boot is a common source for engine smells in the cabin as well.)

It is my understanding that if you vent the P/S side and leave the D/S hooked up to the manifold, regardless if there is a catch can or not, will lean you out because you are allowing unmetered air into your intake. If you want to use your intake as engine vacuum you need to keep the passenger side drawing air from the intake tube after the MAF. Once you open up the system with a breather on the passenger side you have to vent to the atmosphere and not your intake.

If you want to use engine vacuum to draw air out of your crankcase you need to have a closed system, otherwise it acts like a giant vacuum leak. My suggestion if you want to go this route with a centri or turbo you should leave the system intact and add a check valve breather in place of your oil cap. This will run your pvc system like normal when under vacuum, and under boost the pressure will be relieved by the oil cap breather.

Or the simplest way to solve the OP's problem is to relocate the catch can/breather or replace the filter with a hose and run it out the back/underneath of the car somewhere.
 

o2sys

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The vacuum source I'm looking for is so during idle the vapors get pull out of the breather can and away from the car. Ideally I would like to connect it to the exhaust and hope the exhaust scavenging effect is enough to pull the vapors during idle.

I have a centri blower with a blow thru setup if that matters.

I know the factory pcv draws from passengers side but right now the passenger side blows out more vapor than the driver side.

What if I connect the breather can back to the intake manifold with a one way check valve in place?

So during idle the vacuum from the engine will pull the vapors but the check valve will prevent it during anything else but idle?
 
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06 T-RED S/C GT

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It is my understanding that if you vent the P/S side and leave the D/S hooked up to the manifold, regardless if there is a catch can or not, will lean you out because you are allowing unmetered air into your intake. If you want to use your intake as engine vacuum you need to keep the passenger side drawing air from the intake tube after the MAF. Once you open up the system with a breather on the passenger side you have to vent to the atmosphere and not your intake.

If you want to use engine vacuum to draw air out of your crankcase you need to have a closed system, otherwise it acts like a giant vacuum leak. My suggestion if you want to go this route with a centri or turbo you should leave the system intact and add a check valve breather in place of your oil cap. This will run your pvc system like normal when under vacuum, and under boost the pressure will be relieved by the oil cap breather.

Or the simplest way to solve the OP's problem is to relocate the catch can/breather or replace the filter with a hose and run it out the back/underneath of the car somewhere.

Exactly 100% spot on.. When running an open breather system, the factory PCV system has to be completely disabled, otherwise it will allow un metered air to enter the crankcase, causing a huge vacuum leak leaning out the air/fuel mixture.. I know this through personal experience which is exactly the reason I use an oil cap breather with a built in one way check valve along with my UPR oil separator that also has a built in one way check valve as well..

The oil cap breather functions just like the stock oil cap in which the check valve remains fully closed during normal driving conditions while the PCV is under vacuum and then opens up at full throttle when the PCV closes in order to allow the crankcase to ventilate..

Between both the oil separator and one way check valve breather, I can keep the factory PCV system fully intact without crankcase vapor oil entering through the intake manifold and then back into the crankcase..

The vacuum source I'm looking for is so during idle the vapors get pull out of the breather can and away from the car. Ideally I would like to connect it to the exhaust and hope the exhaust scavenging effect is enough to pull the vapors during idle.

I have a centri blower with a blow thru setup if that matters.

I know the factory pcv draws from passengers side but right now the passenger side blows out more vapor than the driver side.

What if I connect the breather can back to the intake manifold with a one way check valve in place?

So during idle the vacuum from the engine will pull the vapors but the check valve will prevent it during anything else but idle?

The reason your passenger side blows out more vapor than the driver's side, is when the factory PCV system is disabled, your intake manifold is capped off and no longer able to pull vacuum out from the driver's side valve cover..
Therefore it's looking for the closest outlet/route for crankcase oil vapors to escape from which happens to be from the passenger side valve cover..

This is why it's recommended to use an oil cap breather that includes a one way check valve, as this provides you with 3 outlets for crankcase oil vapors to escape from rather than from just the driver and passenger side valve covers..

As for connecting the breather can back to the intake manifold with a one way check valve in place, may work.. However it won't prevent the vapor smell from entering the inside of your car through the air vents.. You might just as well be far better off by just keeping the factory PCV system active and run an oil separator/catch can that includes a built in one way check valve along with an oil cap breather which also includes a built in one way check valve as well :shrug:
 
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slackinoff

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Exactly 100% spot on.. When running an open breather system, the factory PCV system has to be completely disabled, otherwise it will allow un metered air to enter the crankcase, causing a huge vacuum leak leaning out the air/fuel mixture.. I know this through personal experience which is exactly the reason I use an oil cap breather with a built in one way check valve along with my UPR oil separator that also has a built in one way check valve as well..

The oil cap breather functions just like the stock oil cap in which the check valve remains fully closed during normal driving conditions while the PCV is under vacuum and then opens up at full throttle when the PCV closes in order to allow the crankcase to ventilate..

Between both the oil separator and one way check valve breather, I can keep the factory PCV system fully intact without crankcase vapor oil entering through the intake manifold and then back into the crankcase..



The reason your passenger side blows out more vapor than the driver's side, is when the factory PCV system is disabled, your intake manifold is capped off and no longer able to pull vacuum out from the driver's side valve cover..
Therefore it's looking for the closest outlet/route for crankcase oil vapors to escape from which happens to be from the passenger side valve cover..

This is why it's recommended to use an oil cap breather that includes a one way check valve, as this provides you with 3 outlets for crankcase oil vapors to escape from rather than from just the driver and passenger side valve covers..

As for connecting the breather can back to the intake manifold with a one way check valve in place, may work.. However it won't prevent the vapor smell from entering the inside of your car through the air vents.. You might just as well be far better off by just keeping the factory PCV system active and run an oil separator/catch can that includes a built in one way check valve along with an oil cap breather which also includes a built in one way check valve as well :shrug:
What/where is a good oil cap breather with the built in check valve?

Sent from my LG-H910 using Tapatalk
 

07 Boss

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The vacuum source I'm looking for is so during idle the vapors get pull out of the breather can and away from the car. Ideally I would like to connect it to the exhaust and hope the exhaust scavenging effect is enough to pull the vapors during idle.

I have a centri blower with a blow thru setup if that matters.

I know the factory pcv draws from passengers side but right now the passenger side blows out more vapor than the driver side.

What if I connect the breather can back to the intake manifold with a one way check valve in place?

So during idle the vacuum from the engine will pull the vapors but the check valve will prevent it during anything else but idle?

If you want to use breathers or a catch can/breather, you can't use any engine vacuum. You can hook up an external pump, but like I said before, I think that is kind of silly. The exhaust may work, but again, that seems like a lot of work for a simple fix.

Just attach a hose to where your breather filter is on the catch can and run it down along the bottom of the car and out near the back somewhere. Then you can attach the breather filter to the end of the hose. This will vent any crank case blow by to the rear of the car and away from the cabin. Or get some longer hoses and mount the catch can away from the engine compartment and cabin.

I run an oil breather cap (no check valve) and two breathers on the valve covers with the PCV valve removed. This gives the motor 3 places to vent and I get very little oil drippage, if any. The check valve 06 is talking about is the one for the oil cap breather. If you hook up your stock PCV system it will operate as intended during idle or non boost situations. Then if you add the oil cap breather with the check valve, it will stay sealed during these times and then when you go under boost it will open up and and allow any pressure in the motor to be release to the atmosphere. This scenario only vents to the atmosphere while moving under boost so fumes should not be an issues as you are only having the issue at idle. So at idle the stock pcv system will not emit any fumes and you won't pressurize the crankcase under boost.

Not sure how to incorporate this with a blow through set up as I have a PD blower and am not as familiar with the intake plumbing. I'm not sure where you would get the metered air for the passenger side. I'm also not sure if this will work with the PCV valve removed too. I would think that the iol cap breather might bleed boost with it opening to the atmosphere. But I am a fan of running all breathers and just changing the oil a little more often. The fumes don't bother me as I kinda like the smell of gas. Brings back memories of my childhood.
 
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o2sys

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Going to try to just put a breather filter on the passenger side and put a check valve from the catch can to the intake manifold. I know this will cause a slight vacuum leak but BruceH and few others have tried this way and the small leak was not really affecting fuel trims due to the leak.

With the blow thru Paxton and no pcv in the driver side cam cover, this seems like a good option without pressuring the crankcase.
 

06 T-RED S/C GT

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Going to try to just put a breather filter on the passenger side and put a check valve from the catch can to the intake manifold. I know this will cause a slight vacuum leak but BruceH and few others have tried this way and the small leak was not really affecting fuel trims due to the leak.

With the blow thru Paxton and no pcv in the driver side cam cover, this seems like a good option without pressuring the crankcase.

Hopes it works out for you.. Just remember if your also replacing the factory oil cap with an oil cap breather, I'd also recommend that it have a one way check valve as well... Just saying!

Thanks !

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Anytime
 

o2sys

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Ok so I went ahead and tried BruceH's hybrid pcv system and wattaya know??? It works!!!

So I swapped driver's cam cover with the pcv still installed (glad never sold it). So now it's connected to a sealed catch can going back to the intake manifold.

The passenger cam cover just has a filter on it, not connected to anything.

Car idles and drives good. Vacuum is good as well (I have a boost gauge).

Best of all no more smell or vapors coming out of hood at stop lights!!!

I will get the CFM oil cap breather and give it a try.

I had the earlier version without the check valve and it would spit oil looked crazy so I hope the check valve will prevent this.
 

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