oil on MAF - BMW 3-Series (E90 E92) Forum

mcpcolas · 01-31-2013, 06:28 PM

i decided to clean my mass air flow sensor today cause my gas mileage been crappy. so when i took it out it was covered with oil. and i didnt have any engine light malfunction or anything. what could cause this.

SharkBait · 01-31-2013, 07:37 PM

New here and know little of the N54 motor yet (about to buy in soon!) but I'd guess turbo seals are potentially leaking oil. I don't know if that's a common issue on this motor or not.

centexE9x · 02-01-2013, 12:16 AM

That's not a maf. Thats a manifold pressure sensor and if you have an N54 then there isn't a Maf on the car. Plus oil in the intake is completely normal on all BMW engines. I've never seen a single one that wasn't at least coated in a thin coat. It's how the crankcase ventilation on these cars is. Totally normal.

mcpcolas · 02-01-2013, 08:22 AM

Quote:

Originally Posted by centexE9x

That's not a maf. Thats a manifold pressure sensor and if you have an N54 then there isn't a Maf on the car. Plus oil in the intake is completely normal on all BMW engines. I've never seen a single one that wasn't at least coated in a thin coat. It's how the crankcase ventilation on these cars is. Totally normal.

Wait there's no MAF on the N54 fuck me . To think I thought I did something , when i really didn't do squat. Well whatever sensor that was it just got cleaned with MAF sensor cleaner , no wonder after I reseted my mpg consumption it settled right back to 12 mpg after a lil drive. Oh well Epic fail

Crewchief05 · 02-01-2013, 08:53 AM

+1

centexE9x · 02-01-2013, 09:27 AM

Sounds like it would be worth pulling the plugs on your vehicle to see if any look really black. Might be a leaking injector(s) killing your mileage. I've heard of other people complain about bad mileage but was never able to verified it.

mcpcolas · 02-01-2013, 09:40 AM

Quote:

Originally Posted by centexE9x

Sounds like it would be worth pulling the plugs on your vehicle to see if any look really black. Might be a leaking injector(s) killing your mileage. I've heard of other people complain about bad mileage but was never able to verified it.

my spark plugs were replace at 32k miles and now im at 44k only have 12k on them

centexE9x · 02-01-2013, 12:21 PM

Quote:

Originally Posted by mcpcolas

my spark plugs were replace at 32k miles and now im at 44k only have 12k on them

I think u misunderstood me. The reason I mentioned taking the plugs out is to see if you have a leaking injector. If so the plugs can turn very dark/black from all the extra fuel. May be a reason for low fuel mileage.

Meeni · 02-01-2013, 01:38 PM

Quote:

Originally Posted by centexE9x

I think u misunderstood me. The reason I mentioned taking the plugs out is to see if you have a leaking injector. If so the plugs can turn very dark/black from all the extra fuel. May be a reason for low fuel mileage.

Wouldn't that trigger an OBD code for running rich on the O2 sensor ?

mcpcolas · 02-01-2013, 01:39 PM

Quote:

Originally Posted by centexE9x

I think u misunderstood me. The reason I mentioned taking the plugs out is to see if you have a leaking injector. If so the plugs can turn very dark/black from all the extra fuel. May be a reason for low fuel mileage.

got it. ill take a look

AWD Addict · 02-01-2013, 01:43 PM

Get an oil catch can. This is just typical vaporized oil blow by that's recondensed once it's far enough from the block and cooled off.

You'll find a similar skim on the inside of the intercooler

tofu- · 02-01-2013, 01:55 PM

Quote:

Originally Posted by centexE9x

Sounds like it would be worth pulling the plugs on your vehicle to see if any look really black. Might be a leaking injector(s) killing your mileage. I've heard of other people complain about bad mileage but was never able to verified it.

leaky injectors would leave him misfiring in worst case scenarios, or give him a rough smokey startup in the morning

raleedy · 02-01-2013, 03:56 PM

Your hands are dirty too.

centexE9x · 02-01-2013, 04:00 PM

Quote:

Originally Posted by tofu-

leaky injectors would leave him misfiring in worst case scenarios, or give him a rough smokey startup in the morning

I'm throwing out scenarios. I've had injectors throw me for a loop and cause all kinds of crazyness. If you believe everything is easy and the same every time then I got some news for you. I've also seen cars running very bad and with crazy lean/rich mixtures throwing no faults. I've been on the BMW brand for 10+years now. The only thing I know is, just when you think you have seen everything you find something new.

deluxe 247 · 02-01-2013, 04:12 PM

It's typical to have oil in your intake. A lot of people run oil catch cans, BMS sells the most popular one and I've heard AR design should be coming out with a new one soon.

marine24 · 02-02-2013, 10:33 AM

Quote:

Originally Posted by mcpcolas

Wait there's no MAF on the N54 fuck me . To think I thought I did something , when i really didn't do squat. Well whatever sensor that was it just got cleaned with MAF sensor cleaner , no wonder after I reseted my mpg consumption it settled right back to 12 mpg after a lil drive. Oh well Epic fail

It's not a MAF but it is the Mass Air Pressure (MAP) sensor; does pretty much the same thing, tells the car the volume of air entering the engine. It gets oil on it because the crankcase feeds back into the air intake stream. Totally normal, and the only way to stop it is to vent the crankcase to the atmosphere. Getting a catch can can help reduce the amount of oil getting re circulated into the system though. I got the one from Burger Motorsports and like it a lot; really helps cut down on the amount coating your intake track

01-31-2013, 06:28 PM	#1
mcpcolas Second Lieutenant Drives: 2009 montego blue 335i xdrive Join Date: Apr 2012 Location: new jersey Posts: 205 iTrader: (0)	oil on MAF i decided to clean my mass air flow sensor today cause my gas mileage been crappy. so when i took it out it was covered with oil. and i didnt have any engine light malfunction or anything. what could cause this. Attached Images
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02-01-2013, 04:12 PM	#15
deluxe 247 Shake and Bake Drives: the girls crazy Join Date: Mar 2011 Location: San Diego Posts: 380 iTrader: (3)	It's typical to have oil in your intake. A lot of people run oil catch cans, BMS sells the most popular one and I've heard AR design should be coming out with a new one soon. __________________ 2007 Space Gray E92 335i 6 speed

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01-31-2013, 07:37 PM	#2
SharkBait Private First Class Drives: 2010 E92 335i Join Date: Jan 2013 Location: Lost Angeles Posts: 145 iTrader: (0) Garage List 2010 BMW 335i (E92) [5.00] 1983 BMW 528e (E28) [5.00] 1988 BMW M6 (E24) [4.50]	New here and know little of the N54 motor yet (about to buy in soon!) but I'd guess turbo seals are potentially leaking oil. I don't know if that's a common issue on this motor or not.

02-01-2013, 12:16 AM	#3
centexE9x Private Drives: e9x coupe Join Date: Dec 2012 Location: austin Posts: 54 iTrader: (0)	That's not a maf. Thats a manifold pressure sensor and if you have an N54 then there isn't a Maf on the car. Plus oil in the intake is completely normal on all BMW engines. I've never seen a single one that wasn't at least coated in a thin coat. It's how the crankcase ventilation on these cars is. Totally normal.

02-01-2013, 08:53 AM	#5
Crewchief05 SBD Drives: 335i e90 Join Date: Dec 2012 Location: Arkansas Posts: 247 iTrader: (0) Garage List 08 335i [0.00]	+1

02-01-2013, 09:27 AM	#6
centexE9x Private Drives: e9x coupe Join Date: Dec 2012 Location: austin Posts: 54 iTrader: (0)	Sounds like it would be worth pulling the plugs on your vehicle to see if any look really black. Might be a leaking injector(s) killing your mileage. I've heard of other people complain about bad mileage but was never able to verified it.

02-01-2013, 01:43 PM	#11
AWD Addict Chief Executive Drives: 2008 335xi 6spd Coupe Join Date: Dec 2007 Location: Boston Posts: 2,320 iTrader: (1) Garage List 2008 335xi [0.00]	Get an oil catch can. This is just typical vaporized oil blow by that's recondensed once it's far enough from the block and cooled off. You'll find a similar skim on the inside of the intercooler

02-01-2013, 03:56 PM	#13
raleedy Major Drives: E92 328i MY 2008 (ED 11/14/07) Join Date: Jul 2005 Location: Portland, Oregon Posts: 1,428 iTrader: (0)	Your hands are dirty too.