Is this "oil blow through"?

badbread · 09-23-2016, 03:04 PM

Hi all,
During the install of a new intake on my car I noticed this in the flex tube part of my intake. Is this the "oil blow through" I've read about that the Oil Catch Can supposedly stops from happening?

Is this any cause for concern? I took a long q-tip and was able to get a little of it on there, smells and looks like motor oil for sure. Most of it was dried up but there was some fresh on there.

[IMG]http://*************/wp-content/uploads/2016/09/IMG_0400-e1474660981901.jpg[/IMG]

Thanks!

Jadar · 09-23-2016, 06:32 PM

Quote:

Originally Posted by badbread

Hi all,
During the install of a new intake on my car I noticed this in the flex tube part of my intake. Is this the "oil blow through" I've read about that the Oil Catch Can supposedly stops from happening?

Is this any cause for concern? I took a long q-tip and was able to get a little of it on there, smells and looks like motor oil for sure. Most of it was dried up but there was some fresh on there.

[IMG]http://*************/wp-content/uploads/2016/09/IMG_0400-e1474660981901.jpg[/IMG]

Thanks!

Yep it is. Pretty common. All f30 I've worked on had it. It's why in time you eventually get that little annoying reminder you're low on oil

RoundelM3 · 09-24-2016, 10:21 AM

The oil is from the Positive Crankcase Ventilation (PCV) system that vents back into the intake tract along with a small amount of oil from the turbo bearings. It would take a VERY long time to have enough oil come through to cause a low-oil indicator, but it's not anything to be concerned about. This system has been improved greatly in the N55 and B58 engines in the F-chassis cars, enough so that an oil catch-can is not necessary.

F32Fleet · 09-24-2016, 02:32 PM

Quote:

Originally Posted by roundel335

The oil is from the Positive Crankcase Ventilation (PCV) system that vents back into the intake tract along with a small amount of oil from the turbo bearings. It would take a VERY long time to have enough oil come through to cause a low-oil indicator, but it's not anything to be concerned about. This system has been improved greatly in the N55 and B58 engines in the F-chassis cars, enough so that an oil catch-can is not necessary.

This unless you just want to burn cash.

Chicken_Joe · 09-24-2016, 10:29 PM

I have had it come up 2 times so far since I have owned my car. I got my F30 in December of 2015. Road tripped it a few times.

badbread · 09-25-2016, 12:32 AM

Thanks for the responses all, appreciate it.

I was really just curious about it. It this what also contributes to the needing of walnut blasting the valve heads?

Thanks!

Chicken_Joe · 09-25-2016, 09:06 AM

That's mainly due to the direct injection. The injectors squirt the fuel directly into the cylinder versus going through the intake manifold first. That's why we have to walnut blast. Cylinders get nasty from fuel hitting them directly from what I understand.

Jadar · 09-25-2016, 11:36 AM

Quote:

Originally Posted by Chicken_Joe

That's mainly due to the direct injection. The injectors squirt the fuel directly into the cylinder versus going through the intake manifold first. That's why we have to walnut blast. Cylinders get nasty from fuel hitting them directly from what I understand.

All motors have blowby since the EPA mandated that manufacturers were not allowed to dump oil in the street or environment like in the early days. Hence manufacturers introduced the pcv valve and it just recirculated and vented the oil from the valve cover back through the intake duct. Has nothing to do necessarily with direct injection since it's been around long before DI was introduced.

EvenKeel · 09-25-2016, 10:09 PM

Quote:

Originally Posted by Chicken_Joe

That's mainly due to the direct injection. The injectors squirt the fuel directly into the cylinder versus going through the intake manifold first. That's why we have to walnut blast. Cylinders get nasty from fuel hitting them directly from what I understand.

The cylinders don't get nasty from the fuel being fired directly into them.

The walnut blasting is to remove carbon buildup on the underside of the intake valves as the valves are NOT being washed by atomized fuel as they would be in a typical port fuel injection system.

TurboM · 09-26-2016, 10:34 AM

Unless the motor is hurt, and getting lots of blow by (cylinder compression making it past the piston rings into the crankcase) the amount of oil making it back to the intake track is very minimal and not a concern.

Or if you're pushing significantly more power than stock (+ ~200hp) which in turn creates more cylinder pressure and blow by, a catch can is typically not needed.

Love the direct injection response, btw

09-23-2016, 03:04 PM	#1
badbread not good, but bad 333 Rep 361 Posts Drives: 2013 335i Join Date: Jun 2016 Location: Bay Area, CA iTrader: (3)	Is this "oil blow through"? Hi all, During the install of a new intake on my car I noticed this in the flex tube part of my intake. Is this the "oil blow through" I've read about that the Oil Catch Can supposedly stops from happening? Is this any cause for concern? I took a long q-tip and was able to get a little of it on there, smells and looks like motor oil for sure. Most of it was dried up but there was some fresh on there. [IMG]http://***********/wp-content/uploads/2016/09/IMG_0400-e1474660981901.jpg[/IMG] Thanks! __________________ They are spelled BRAKES** not breaks!!!! Oh FFS, not another spark plug thread! BreadsBMW on Youtube
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09-24-2016, 10:21 AM	#3
RoundelM3 Major General 1838 Rep 6,991 Posts Drives: 15 F80 M3, 22 G01 X3 30i Join Date: Apr 2010 Location: Clayton, NC iTrader: (2) Garage List 2022 BMW X3 [9.83] 2015 BMW M3 [6.50]	The oil is from the Positive Crankcase Ventilation (PCV) system that vents back into the intake tract along with a small amount of oil from the turbo bearings. It would take a VERY long time to have enough oil come through to cause a low-oil indicator, but it's not anything to be concerned about. This system has been improved greatly in the N55 and B58 engines in the F-chassis cars, enough so that an oil catch-can is not necessary. __________________ 2015 F80 ///M3 Sedan 7DCT Tanzanite, 2022 X3 sDrive30i 8AT Brooklyn Grey
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09-24-2016, 10:29 PM	#5
Chicken_Joe Lieutenant Colonel 608 Rep 1,782 Posts Drives: 2013 F30 335i M Sport. EB 6M Join Date: Dec 2015 Location: Frontenac, Missouri iTrader: (3)	I have had it come up 2 times so far since I have owned my car. I got my F30 in December of 2015. Road tripped it a few times. __________________ 13' 335i M Sport. EBII/Coral Red 6MT. RPI GT exhaust, Resonator delete, PS1, GFB DV , BM3 Stage 2, ER CP, VRSF DP, VRSF 5.5in Stepped FMIC, Dinan Shockware. Carbon M Performance rear diffuser. M4 trunk lip. Conti DWS06 225/40/19 and 255/35/19
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09-25-2016, 12:32 AM	#6
badbread not good, but bad 333 Rep 361 Posts Drives: 2013 335i Join Date: Jun 2016 Location: Bay Area, CA iTrader: (3)	Thanks for the responses all, appreciate it. I was really just curious about it. It this what also contributes to the needing of walnut blasting the valve heads? Thanks! __________________ They are spelled BRAKES not breaks!!!! Oh FFS, not another spark plug thread! BreadsBMW on Youtube
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09-25-2016, 09:06 AM	#7
Chicken_Joe Lieutenant Colonel 608 Rep 1,782 Posts Drives: 2013 F30 335i M Sport. EB 6M Join Date: Dec 2015 Location: Frontenac, Missouri iTrader: (3)	That's mainly due to the direct injection. The injectors squirt the fuel directly into the cylinder versus going through the intake manifold first. That's why we have to walnut blast. Cylinders get nasty from fuel hitting them directly from what I understand. __________________ 13' 335i M Sport. EBII/Coral Red 6MT. RPI GT exhaust, Resonator delete, PS1, GFB DV , BM3 Stage 2, ER CP, VRSF DP, VRSF 5.5in Stepped FMIC, Dinan Shockware. Carbon M Performance rear diffuser. M4 trunk lip. Conti DWS06 225/40/19 and 255/35/19
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09-26-2016, 10:34 AM	#10
TurboM Captain 252 Rep 674 Posts Drives: 2018 F82 M4 ZCP Join Date: Nov 2013 Location: Atlanta iTrader: (1)	Unless the motor is hurt, and getting lots of blow by (cylinder compression making it past the piston rings into the crankcase) the amount of oil making it back to the intake track is very minimal and not a concern. Or if you're pushing significantly more power than stock (+ ~200hp) which in turn creates more cylinder pressure and blow by, a catch can is typically not needed. Love the direct injection response, btw
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