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Discussion Starter #1
Is it normal for a light amount of smoke/oil vapor to come from the intake plenum if you have driven your car for awhile? Engine hasn't really run for probably close to 6 months.. Gas tank is also half full and been sitting awhile.

If not, what might cause this issue? And another question is what might cause a heavy burning/consumption of oil? Keep in mind, the engine was not not up to temperature while this smoke/vapor was coming from the plenum.
 

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Do you have any power steering fluid leaks from the hoses , or any oil stains from around the valve cover?

mine did that too within minutes of cold engine start. Especially After spraying some wd40 when i was changing the ignition coils
 

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Discussion Starter #3
It's very easily possible. I've sprayed a ton of solvents underneath the engine and probably on top as well. I also applied grease around the throttle bodies to make it easier to install/remove the plenum.
 

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What do you mean "coming from the plenum"? The intake plenum is a closed system? Nothing comes out of it.
 

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Yea man, **** like WD40 and similar even if they are dried will smoke like a train. It scared the hell out of my first few times i started my car and was surprised by how fast it started smoking, thought it was about to catch on fire. My car too was actually sitting for like 8 months. You might want to throw some octane booster or fuel stabilizer in there though, and/or add fresh fuel to it... gas has an expiration date for the most part.
 

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Discussion Starter #7
Yeah, seems to be gone after having the engine run for awhile while bleeding power steering.
 

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Discussion Starter #8
I'm just slightly paranoid because I either have a problem with serious oil consumption or my oil level sensor failed. I just replaced the sensor, so I'll know for certain in the next few weeks whether I actually have a problem with oil consumption.
 

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You sure its not your voltage regulator on the alternator? You should of seen the christmas lights before i replaced mine

the engine temperature gauge and oil sensor would go bananas in particular since they are on the same BSD line system
 

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Discussion Starter #10
You sure its not your voltage regulator on the alternator? You should of seen the christmas lights before i replaced mine

the engine temperature gauge and oil sensor would go bananas in particular since they are on the same BSD line system
Alternator is pretty much new. No Christmas lights either.
 

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Regarding oil consumption, BMWs are known to have leakage from the valve seals, I don’t think S85 is any exception to that. If you have a boreoscope, take a look at the back of the intake valves by going through the throttle body. Sounds like you already have the plenum back on but it may make sense to remove it again to check it out. The other issue that can contribute to oil consumption is plugged/blocked PCVs. There are 4 total, 2 of them can be only be accessed when the trans is dropped. The other 2 are on the cam covers.
 

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Discussion Starter #12
@gmtegear Just replaced all four PCVs when I was doing the rod bearings and had the SMG out. I'll probably drive around the next few weeks and see if oil consumption is even an issue. I've also had pretty poor gas mileage, but that could probably due to a lot of things. I'll have to check vanos solenoid operation too. I also read through the thread on here about grounding, so I might look into that as well.
 

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@gmtegear Just replaced all four PCVs when I was doing the rod bearings and had the SMG out. I'll probably drive around the next few weeks and see if oil consumption is even an issue. I've also had pretty poor gas mileage, but that could probably due to a lot of things. I'll have to check vanos solenoid operation too. I also read through the thread on here about grounding, so I might look into that as well.
Man, you wouldnt believe the kind of gas mileage i’ve been getting recently. I used to drive around with 6-9mpg city/highway... now its 12mpg city and 23mpg highway. Im blown away. Been running 4 tanks of fuel cleaner so far... Techron. Changed alternator and added more ground wiring from the engine to chassis. Cleaned MAF sensors. Havent even changed out my precat O2 sensors yet... i think that’ll improve it more so. Best part is... the engine pulls like ive never seen before. Almost like ive been driving it in some kind of limp mode for a long time.
 

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Discussion Starter #14
@Dmitry911 Would you attribute the better gas mileage to the grounding? My alternative is probably less than 1000 miles old, but the grounding issue sounds very interesting. Did you just add another ground cable from the alternator to the chassis and another from the engine to chassis?

6-9 mpg sounds about like what I'm getting now. It's pretty horrible.
 

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@Dmitry911 Would you attribute the better gas mileage to the grounding? My alternative is probably less than 1000 miles old, but the grounding issue sounds very interesting. Did you just add another ground cable from the alternator to the chassis and another from the engine to chassis?

6-9 mpg sounds about like what I'm getting now. It's pretty horrible.
Yea, idle is incredibly stable now along with overall throttle response. The idle hunt before and after grounding is how i knew the grounding was making a huge difference for me. What i did was buy a couple 4 gauge battery cables from Autozone and bolt a cable from the passenger side chassis located just above the ECU box when you left the black AC filter holder. Its the one with brown ground already bolted to it. Bolt it to the passenger side of the engine Under the cover where the crankshaft sensors are located. There you will find 2 existing smaller ground cables bolted to the engine block. Unscrew one of those bolts and fit your new ground cable to it. Do the same on the other side. then one cable between the 2 sides of the engine. A long cable going from chasis to the alterator is probably Overkill and im sure would work just as good without it tho.

theres pictures in my post here:

I think these ground cables make the ECU perform things much faster hence why car drives so much better. It was getting 12-18mpg right away and then it kept improving to 23mpg highway

i think its a combination of the Techron fuel cleaner and these new grounds though ultimately
 
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