Gas getting into engine oil....lots of it

[gtdragon980]

So after trying to figure out why my car gets a shitty 9mpg, i found out my trip i was using to calculate it was off..by a lot! I would easily drive over 20 miles and it would show maybe around 9. Stupid me for not noticing that in the beginning. I have yet to get a proper calculation yet, so i will update with that later. But why am i still getting a lot of gas in my oil? I can smell a strong fuel odor from the dipstick and my oil is losing its viscosity very quick! It definitely is running a bit rich and i've replaced almost every sensor on my car. The only thing i dont have running on it is my o2 as i need a new oem one. It's unplugged atm so the ecu doesn't get bad readings. Fuel Injectors are freshly rebuilt, CTS is new, AFM is refurb, and ICV tested and good. I can't think of anything else right now but im stumped as to what is the cause of the gas getting in my oil? Im going to do a compression test on the car soon, but i want to know what else should i look for. The engine has very low miles, atleast thats what my odo says. I've personally looked at the head and it is clean in and out so I can partially believe the mileage is accurate. Thanks in advance for your opinions!

[whodwho]

I would suspect a leaking injector and bleeding off fuel pressure when shut off if you are getting raw gas in the oil.

[jlevie]

There are only a few thinks that can cause the engine to run rich enough to cause a fuel smell in the oil.

For an 325e, a bad cold start valve or bad time-temperature sensor are possibilities

For all E30 variants the list is:

Excessive fuel pressure
A engine running cold or a bad ECT sensor
Bad AFM
Leaking injectors
Bad engine harness
Bad DME
Partially plugged catalytic converters or exhaust

That, of course, is for a stock engine. Oversize injectors can be another cause.

With the new & refurb parts most of the possibilities should have been eliminated. But you need to check fuel pressure in the rail, preferrably at idle and while driving. A missing O2 sensor will cause the DME to revert to conservative (slightly rich) maps, but that shouldn't be enough to cause the oil to smell of fuel.

[bmwstephen]

what oil are you are using? I'm using mobil one and it smells like gasoline in all the cars I've owned

[gtdragon980]

Rotella T synthetic. It's fairly thick but after several hundred miles, it thins out quickly and smells like straight up gas.

[gtdragon980]

Okay so I can eliminate..
AFM
Injectors
Engine harness, since i rebuilt the c191 connector.
And catalytic, since i am not running one.

That leaves me with the DME, and running cold because my car tends to sit at about 1/4 of the temp gauge. Is there nothing internally that could allow for gas to enter my crankcase and oil?

Also, I forgot to add, but is it normal for the car to seem sort of dead on power around the 1k-2k range? You can feel a sluggish pull in that range, but after 2k it pulls hard.

[Adrian_Visser]

The FPR can leak fuel through its diaphragm into its vacuum hose check that too.

[gtdragon980]

The FPR can leak fuel through its diaphragm into its vacuum hose check that too.

Also a good point, and forgot to mention i tested that too and it was good. Last time i checked my fuel pressure, it was normal. I'll do it again and see whats going on.

[jlevie]

The engine harness is still a suspect, but it is further down the list than the other possibilities. Switched power is provided to all of the injectors and the DME gounds each bank to fire the injectors. There can be a fault in the harness that has the injectors partially grounded all the time. That can increase the amount of fuel delivered per firing pulse.

If the gauge and thermostat are working properly the needle should be well above the 1/4 mark, but a bit below the 1/2 mark when the engine is at normal temperature and being driven at 35mph or faster with an 80C thermostat. If a 75C thermostat is used the needle will rest about half way between those marks. If your gauge is indicating lower than that, the thermostat may be bad.

[gtdragon980]

I guess I oughta check the temperature with a different source, since the gauge tends to fluctuate. I've seen the needle sit right above the blue and i've also seen it sit at halfway. But, most of the time it sits at 1/4.

As for the injectors, thats very interesting. I did not know that it could do that. I am not too worried about that since I replaced my harness with another known good one and swapped my rebuilt c191 connector off my old one to this. Yet it still has the same problem so i have a feeling this is the last of my worries.

[bmwstephen]

I guess I oughta check the temperature with a different source, since the gauge tends to fluctuate. I've seen the needle sit right above the blue and i've also seen it sit at halfway. But, most of the time it sits at 1/4.

As for the injectors, thats very interesting. I did not know that it could do that. I am not too worried about that since I replaced my harness with another known good one and swapped my rebuilt c191 connector off my old one to this. Yet it still has the same problem so i have a feeling this is the last of my worries.

something is seriously wrong. it should be a hair below the half way mark once warmed up