What the hell is this in my OCC?

[Swadeness]

While I was changing my oil today I decided it was a good time to also check my oil catch can. This was my first time checking the can since it has only been installed for maybe 2-3000 miles tops. I was shocked when I found this in the bottom of it. A mixture of mostly water, rust?, and a little bit of oil. Where the hell did the rust come from? Is this whats going through the motor on a regular basis? Somebody please post a valid explanation or best guess of whats going on here.

[Mike@N54Tuning.com]

It's a mixture of water from crankcase condensation, fuel vapors, and oil. Just the sort of crap you want to get out of the system.

Mike

[Elsabor67]

Wow Wade........That is scary. The oil you changed didn't look like this did it?

[Swadeness]

I understand the crankcase condensation. In fact I've seen pictures on here showing a soupy water and oil mixture in the catch can so I think that is probably pretty normal, especially on a N55. I am a little concerned where the rust is coming from though. Is it coming from the crankcase? Is it in the oil? Has anybody else ever seen something similar in their OCC?

[Swadeness]

Originally Posted by Elsabor67

Wow Wade........That is scary. The oil you changed didn't look like this did it?

The oil looked pretty "normal" I guess. Actually it looked good considering it had been through stelvio, lots of high speed runs on the autobahn, and numerous ring trips, it definitely was not rusty looking or odd smelling. The magnetic drain plug had the typical light coating of a fine grey graphite like material but nothing abnormal.

[trickcruiser]

Just changed mine and while it was not exactly like yours it was similar. I would not be concerned unless your oil from the drain plug looked like this. I am very happy to see the catch can doing its job!

[Stohlen]

where do you see rust?

[Dackelone]

I guess the rust your talking about is that scum floating in that broth/mixture?

Maybe use a magnet to pick out the rust particles ? Or have whats in your OCC sent to an oil lab. As far as where the "rust" is coming from... with your OCC install... did you use any steel T's to plumb it in? Just a guess. ?

[Swadeness]

Originally Posted by Dackelone

I guess the rust your talking about is that scum floating in that broth/mixture?

Maybe use a magnet to pick out the rust particles ? Or have whats in your OCC sent to an oil lab. As far as where the "rust" is coming from... with your OCC install... did you use any steel T's to plumb it in? Just a guess. ?

Actually the rust I'm talking about was dissolved in the water. There was some pin head sized pieces of rust and grime, but for the most part the rust was mixed in with the water. The pic doesn't quite do the color justice. The water was an orange color, smelled like rust, and didn't have much oil in it at all.

As far as I remember there were no metal fittings used only rubber and plastic that came with the kit. I guess it could be from one of the fasteners holding the baffle in place but I think that is unlikely. It's starting to sound like this may be normal. Either way I'm going to check it regularly for a while to satisfy my curiosity.

[tracer bullet]

If you know you have small metal particles in the oil, and there is oil in the catch can, and there's also vapor in the catch can, then did the metal particles get rusty after they were trapped?

[Stohlen]

I do not think you have rust in your catch can. I don't know where it would have come from, since this is an aluminum engine. Also rust doesn't smell, so i'm not sure what smell you are talking about.

[bmw1racer]

Oil Catch Can?

[Tee-Dub]

Gotta get me one of these!

[jsmonet]

if the oil out of your pan didn't look like a frothy milkshake, it's all good. the catch can isn't a good indicator of things like blown headgaskets. don't get freaked out

[Todd135i]

Out of curiosity, is it getting really cold there?
This is my first winter season with my 135i, but not the first season with a catch can on one of my vehicles. On other vehicles I had to watch and dump the OCC more frequently in the winter. It came out looking just like yours in the winter.

Just food for thought.

[Rowdy]

Quick question.. are there any differences in OCC's between n54 and n55?

If so.. whats the best bet for the n55? Had a BSH OCC on my Cooper S and it worked great! Only saw there listing for n54.. and it made me wonder.

[Swadeness]

Originally Posted by tracer bullet

If you know you have small metal particles in the oil, and there is oil in the catch can, and there's also vapor in the catch can, then did the metal particles get rusty after they were trapped?

I'm beginning to think this is the most likely scenario. The car had been sitting for a bit over a week since its last drive. Maybe in that time some of the fine particles in the oil/water vapor began to oxidize.

Originally Posted by Stohlen

I do not think you have rust in your catch can. I don't know where it would have come from, since this is an aluminum engine. Also rust doesn't smell, so i'm not sure what smell you are talking about.

As far as smell, maybe a metallic smell is a better way to describe it? Have you have ever lived in a old house with rusty water pipes or smelled water with a high iron content? It smelled just like that.

Originally Posted by Todd135i

Out of curiosity, is it getting really cold there?
This is my first winter season with my 135i, but not the first season with a catch can on one of my vehicles. On other vehicles I had to watch and dump the OCC more frequently in the winter. It came out looking just like yours in the winter.

Just food for thought.

Yeah the weather has started to turn cold here. It's good to know that this is probably normal.

[Indo Rider]

Never had any water at all in my occ, but its pretty warm here in San AnTonio so maybe only people in colder climates get enough condensation to see something like that in their catch can. Nothing but straight black oil in mine.

[RimasRS]

I see it normal that is what OCC should do collect condensation and crap oil