Chocolate Milk in my Intake Boot...

[bimmerboy12]

I took my AFM/Airbox off my intake boot, and there was quite a bit of a light brown liquid in there... the color of chocolate milk. It was enough to fill the bellows of the intake boot and run out. It looked like it was sprayed from the intake side towards the AFM. Keep in mind it is about 10 degrees out and I just had pulled it in to an 80 degree garage an hour or two before. Any ideas? I may have seen some water bubbles in it too.

[kenika65]

ice mixing with sludge = chocolate milk umm does the body good...

[wagonizzle]

You should look at your oil and coolant too... chocolate milk is not so good. Head gasket or maybe worse...

[Miasma]

Blown HG, Check the coolant. It could be just a HG or it could be that and a warped or cracked head, Have you overheated it?

[kenika65]

It is in the intake boot...

He said that it is 10deg out which will cause freezing

[Miasma]

And why is there water and oil mixed together in the intake boot? Cause it is freezing?

[kenika65]

yes that is why they make Throttle body heaters duhhhhh lol To eliminate freezing

and since our e30 dont have a oil catch can oil residue coats the inside of the intake system which has mixed with H20 and caused the brown ness

[Miasma]

Sure, That explains it.

Weird that out of 3 m20's I have had apart the only one that had this symptom was one with a blown HG.

And there should be no water/ice in the intake bellows.

[Miasma]

And furthermore the cold start coolant circuit that run's through the TB cant leak into the engine it isn't setup that way AFIK.

[kenika65]

So any updates OP?

[gearheadE30]

Only reason for that would be if the crankcase vent was messed up. There is no way that that sludge should even be in that large of a quantity, much less in the intake boot.

[bimmerboy12]

Only reason for that would be if the crankcase vent was messed up. There is no way that that sludge should even be in that large of a quantity, much less in the intake boot.

Where is the crankcase vent?

[kenika65]

hey your back so how does your oil and coolant look?

[gearheadE30]

I'm not entirely sure on the M20, but it will be coming out of a high point on the cam cover, possibly under the intake manifold. It will run to a point just aft of the throttle body on the intake manifold. The entire idea behind it is that during ignition, a small amount of pressure escapes around the piston rings. That pressure needs to go somewhere, so it is routed back into the engine to be burned. This helps to a small degree with air metering, but, more importantly, it burns up the inert oil-air mixtre from the innards of the engine. If your engine has too much blowby (i.e. bad piston rings) an excess amount of oil and air may be travelling through the crankcase vent, or PCV, valve. A leakdown test is all that is needed to check this.

[bimmerboy12]

hey your back so how does your oil and coolant look?

My oil looks fine. I just replaced the T-shaped heater hose, so saw a lot of coolant and it looks fine since I did the flush this past summer.

I am wondering if the inside of the intake just "sweat" a lot when coming in from the cold into a hot environment. From what I have read elsewhere, some oil in the intake boot is normal.