[mcpcolas]

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]

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]

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]

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]

+1

[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.

[mcpcolas]

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]

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]

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]

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]

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-]

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]

Your hands are dirty too.

[centexE9x]

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]

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]

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