Oil catch can muck

[Daryl]

I recently installed a oil catch can on my 2012 Ram 1500 5.7
Per the recommendation, I’ve checked it every couple of weeks. Is the milky brown “muck” that I’m cleaning out of the can “blow by”? I
There’s no drop in oil level, so I’m curious what it is I’m getting rid of in there?

 

[96blak54]

Hard to say. Might just only be moisture.

 

[ttocs]

I thought it was normal for some water to collect in them as much as oil?

 

[duh09]

Little bit of oil, little bit of condensation forming in the can, little bit of moisture coming from the engine before it’s fully warm.

 

[RAU03MACH]

its normal to have a little water
hot to cold condensation

 

[ju015dd]

I have had a catch can on my bronco since new. Weirdly, zero caught .

 

[RAU03MACH]

I have had a catch can on my bronco since new. Weirdly, zero caught .

If it's an older 50 58 75 they really don't need them
The baffles in the valve cover were better on those engines
The newer 4.6 the baffles are not there in the valve cover just a little shield so the oil gets picked up vacuum

 

[cobrajeff96]

It's nothing to worry about. Especially if it doesn't drain right back into the oil pan to get re-used. If that were the case, it'd be not ideal. There's outfits out there that actually put in ports to route hot coolant around the catch can just for that purpose (to recycle it back to the pan). It keeps the PCV mist hot and free of moisture, which is the brown milky muck you see.

Unlikely there is blow by, you'd notice a loss of power.

Mine is the same. I don't have it recycled and I check it often, like every 500mi because the passenger side one is piped in behind the throttle body and sees a lot of vacuum (during idle). It fills up with the muck quickly. The driver side one is piped into the CAI between the MAF and throttle body and so I hardly check it because when I do it's bone dry.

 

[white95]

Condensation…

 

[wmfateam]

Passenger catch can on my 3.5 Ecoboost gets a brownish liquid gunk every 1000 miles or so. Drivers side is just an oil cap breather. Same setup I had on my 2017 GT with the same results.

 

[Daryl]

Passenger catch can on my 3.5 Ecoboost gets a brownish liquid gunk every 1000 miles or so. Drivers side is just an oil cap breather. Same setup I had on my 2017 GT with the same results.

Yeah, that’s what I’m getting too. If I remember, I’ll post a pic when I get home from work today.

 

[95opal]

The milky white is just condensation mixing with the oil. Your fine unless it's recirculating back to the motor

 

[TTSaleen]

As stated. The longer you have it the more oil residue mixes with condensation and will have a "muck" or off white/yellow color sometimes. If you ever run E85 in a engine, you will have lots of water/condensation and this muck over time.

 

[HOURSEBLACK]

Yes, what you describe sounds like "blow-by" mixed with condensation. I have exactly the same thing in my catch can, especially when the temperatures are lower. It is a mixture of oil, water vapor and combustion residues. As long as your oil level remains stable and the engine is running well, nothing to worry about. It is better that it is in the catch can than in the admission! I empty it regularly too, it's crazy what it accumulates. Good move to have installed one!

 

[Daryl]

Yes, what you describe sounds like "blow-by" mixed with condensation. I have exactly the same thing in my catch can, especially when the temperatures are lower. It is a mixture of oil, water vapor and combustion residues. As long as your oil level remains stable and the engine is running well, nothing to worry about. It is better that it is in the catch can than in the admission! I empty it regularly too, it's crazy what it accumulates. Good move to have installed one!

Thanks, I appreciate the feedback. Oil level remains perfect, but good to know what that “sludge” is comprised of! Yes, definitely better in the can than in the trans. Glad even more so now that I installed it ;-)