OIL blow by on Driver Side

[apex15stangPP]

Catch cans on the market are always shown on the passenger side, I don't have an issue with oil on the passenger side, but Im getting a ton of oil from the driver side!! So much the intake keeps popping off, and is coated in oil, anyone else? I'm going to try running both sides to one large catch can with a breather to see if it helps but as of now seems like I'm getting way to much oil out the driver side crankcase breather!!

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[MontelG]

Catch cans on the market are always shown on the passenger side, I don't have an issue with oil on the passenger side, but Im getting a ton of oil from the driver side!! So much the intake keeps popping off, and is coated in oil, anyone else? I'm going to try running both sides to one large catch can with a breather to see if it helps but as of now seems like I'm getting way to much oil out the driver side crankcase breather!!

I just installed the UPR passenger side catch can about 100 miles a go. I just checked it and it is bone dry. I don't really have any way to know if there is blow by one the driver side.

When I was shopping for it I saw one brand, don't remember which one, that offered a driver side kit which was standalone. I like the idea of two separate units as opposed to one. That's just me though.

 

[ridenfish39]

Catch cans on the market are always shown on the passenger side, I don't have an issue with oil on the passenger side, but Im getting a ton of oil from the driver side!! So much the intake keeps popping off, and is coated in oil, anyone else? I'm going to try running both sides to one large catch can with a breather to see if it helps but as of now seems like I'm getting way to much oil out the driver side crankcase breather!!

That does not sound good. Usually you only get blow by on the passenger side with naturally aspirated cars. My JLT passenger can catches very little on my 15, it caught a ton on my 12 though. If you don't have a blower on your car then I would take it in for service.

 

[Walt1120]

Catch cans on the market are always shown on the passenger side, I don't have an issue with oil on the passenger side, but Im getting a ton of oil from the driver side!! So much the intake keeps popping off, and is coated in oil, anyone else? I'm going to try running both sides to one large catch can with a breather to see if it helps but as of now seems like I'm getting way to much oil out the driver side crankcase breather!!

What intake is popping off? You sure something isn't blocked on the passenger side pcv, the only time any air even comes out of the drivers side is when the car is under heavy throttle, and obviously those few secs wouldnt be enough to create large amounts of oil

You cant run them both to the same catch can. The passenger side is connected to the intake manifold and the driver is connected to the intake tube. The passenger side should always enter the motor in a place under vacuum and thats why its on the intake manifold (after throttle plate) so that area is always under vacuum (regardless if throttle body is open or closed). The drivers side is connected to the tube which is open to the atmosphere. Basic pressure flow will tell you that the natural path would be for the air to flow from the intake tube to the drivers side cover, out the passenger side cover and into the intake manifold since pressure flows from high to low (atmospheric to vacuum in this case)

The pcv system therefore wont work properly if you combine them

The drivers side pcv line only feeds the make up air which is sucked out through the passenger side, if your getting oil blowing out of the drivers side than something isnt right with the pcv system. Have you changed anything?

 

[Crais]

Unless I'm mistaken:

The PCV system should work fine if combined provided you have an appropriate source of vacuum. Both the passenger and driver side are pulling gases from your crank case, the amount of oil caught on the passenger side is a side effect of the vacuum source location (after the throttle plate). The reason we have two PCV lines with asymmetrical flow is because one (passenger) is the primary egress for the crank case gases while the secondary (driver) provides small flow for the gases on the top end of that side that otherwise would cause gunk in your head.

That being said, there's nothing to prevent you from using a passenger side catch can for the driver side by simply using the appropriate hoses/clamps/whatever hardware.

Before you invest too much thought into this, you should really hit up the dealership if you're having significant oil condensation or blow by from the driver side. Definitely a sign something in the system isn't functioning properly.

 

[Walt1120]

Unless I'm mistaken:

The PCV system should work fine if combined provided you have an appropriate source of vacuum. Both the passenger and driver side are pulling gases from your crank case, the amount of oil caught on the passenger side is a side effect of the vacuum source location (after the throttle plate). The reason we have two PCV lines with asymmetrical flow is because one (passenger) is the primary egress for the crank case gases while the secondary (driver) provides small flow for the gases on the top end of that side that otherwise would cause gunk in your head.

That being said, there's nothing to prevent you from using a passenger side catch can for the driver side by simply using the appropriate hoses/clamps/whatever hardware.

Before you invest too much thought into this, you should really hit up the dealership if you're having significant oil condensation or blow by from the driver side. Definitely a sign something in the system isn't functioning properly.

The primary function of the drivers side hose is to provide fresh air to the crankcase to replace whats being pulled from the passenger side. The pressure inside the intake tube is different than the pressure inside the intake manifold unless your at or close to full throttle or very high gear like 6th.

Therefore there would always be some flow traveling from driver side hose and out the passenger side cover. Even if both are under vacuum, whatever has the stronger vacuum will determine the flow and in this case the passenger side hose is under more vacuum

The pressure difference between the passenger side hose and drivers side hose in strongest at idle, as you apply more throttle and engine vacuum decreases, the pressure difference between the two pcv lines decreases until they pretty much reach no differential at WOT, since the throttle plate is wide open. This means that the pcv system is drawing the "hardest" at idle and the least while at wot, which makes sense since you don't want to be drawing crankcase gas into the intake under decent throttle as there is alot of oil flowing around in the head and the potential for oil getting sucked up would be increased greatly

The only time that anything could ever be reverse flowing (out of drivers side) is under wide throttle in high gear, and even then this possible draw would be very very minimal. Large amount of oil out the drivers side should never be occurring on this car unless a blower/turbo is hooked up using stock pcv configuration.

in short, the easiest way I can describe it is that the pcv system provides a constant blanket of fresh air in the crank case and flows in from the drivers side and out the passenger side, carrying out harmful gases

If you only had vacuum on the crankcase, then there would only be an exit for gases and no inlet of make up air. This means the only thing coming "into" the crankcase would be blowby gas and it would leave through the vacuum source. This would be less effective as there would be no fresh airflow that acts as a carrier gas to flush out blowby gases as they enter the crankcase. Blowby gases can cause premature breakdown and acidification of motor oil so you want them to be flushed out as soon as possible

Modern pcv systems all function by providing a constant flow of metered air through the crankcase

 

[Crais]

Thank you for that explanation, this is very different from any car I've owned, looks like I need to re-learn a few things I take for granted.

 

[DanielElCoyote]

Did you happen to find the issue causing this?

 

[NightmareMoon]

There was a design issue with the cam cover design on the 2015-17s, can get drivers side oil under very hard sustained right sweepers followed by a hard left and throttle.

Most will never see that type of use case.

You can get the Ford Performance aluminum cam covers and/or a carch can.

If you have an 18+ you shouldnt be seeing much/any drivers side oil unless something is funny.

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