[artey34]

Checked my Mishimoto catch can on my 18 SS 1LE today after 500 miles. I had the oil changed last time I drained it so fresh oil. It looks like Coffee. What the hell? The first time I drained it it looked like the image with the dark oil after 900 miles. 2nd change after 500 miles is yellowish???? What could it be??

[GP86]

That's normal when it gets cold. I believe you end up getting more water in the mixture and it becomes that milk chocolate type color. Mine is the same way this time of year through Winter.

[SSDan]

Yep - the colder is gets job the more it will look like creamy coffee.

[artey34]

So it just looks like this in the catch can? The oil in the pan should still look normal I assume? I should drain a little bit to check

[hotlap]

Originally Posted by artey34

So it just looks like this in the catch can? The oil in the pan should still look normal I assume? I should drain a little bit to check

The oil in the pan is not milky. Your just condensing water in the can.

I do recommend caution. I had a catch can on my 2016 and as temperatures dropped into the low teens the can was filling with water in one weeks time. The result was the crank case wasn’t venting properly and the oil reeked of fuel.

After I found the can this full in four day, I took if off and changed the oil. Because it was cold outside I had the garage door down and the garage smelt like gasoline. I won’t put a can on a car ever again.

[hammdo]

Normal, no need to drain the oil...



-Don

[camaroJD]

Originally Posted by hotlap

The oil in the pan is not milky. Your just condensing water in the can.

I do recommend caution. I had a catch can on my 2016 and as temperatures dropped into the low teens the can was filling with water in one weeks time. The result was the crank case wasn’t venting properly and the oil reeked of fuel.

After I found the can this full in four day, I took if off and changed the oil. Because it was cold outside I had the garage door down and the garage smelt like gasoline. I won’t put a can on a car ever again.

I never realized this was a problem in cold climates but it makes sense. I'm re-thinking using the catch can I just bought. Just out of curiosity, what brand was yours?

[Stewhoppy]

Guys, is it possible to add a vent/breather to the Mishimoto catch can?

[Warrior102]

Originally Posted by hotlap

The oil in the pan is not milky. Your just condensing water in the can.

I do recommend caution. I had a catch can on my 2016 and as temperatures dropped into the low teens the can was filling with water in one weeks time. The result was the crank case wasn’t venting properly and the oil reeked of fuel.

After I found the can this full in four day, I took if off and changed the oil. Because it was cold outside I had the garage door down and the garage smelt like gasoline. I won’t put a can on a car ever again.

I would dig into that a little deeper Hotlap, it sounds like you have other problems if that much fuel is showing up you can smell it. I'd have the dealer do a leak down test on the injection system. Having water condense in the vent system and even on the inside of the fill cap is quite normal this time of the year especially if you do short trips.

[mdhopt36]

Yes- and water in the can in cooler weather, means more frequent oil changes during cold weather, being that it's inside the engine.

[Airfuel]

And that is exactly why it is bad to start your engine once a week or month like a lot of people think they need to do when a car is in hibernation during winter!

It takes awhile to get 10 (or eight) quarts of oil up to operating temp long enough to burn off that moisture.

This is also why frequent short trips are considered “severe service” in regard to oil change frequency
.

[hotlap]

Originally Posted by camaroJD

I never realized this was a problem in cold climates but it makes sense. I'm re-thinking using the catch can I just bought. Just out of curiosity, what brand was yours?

I had a Mishimoto can on my 16.

Originally Posted by Warrior102

I would dig into that a little deeper Hotlap, it sounds like you have other problems if that much fuel is showing up you can smell it. I'd have the dealer do a leak down test on the injection system. Having water condense in the vent system and even on the inside of the fill cap is quite normal this time of the year especially if you do short trips.

The PCV system uses the intake manifold vacuum to remove fumes from the crank case. Those fumes are blow-by leakage of the air/fuel mixture from the combustion process. If the can fills up with water, the crank case can’t vent and that mixture condenses into the oil pan. If the pressure gets too high, you can blow seals.

The Mishimoto can is small so I checked it often. When I found it full of water twice (week intervals) and the oil loaded with gas, I took it off at 7,300 miles. I didn’t have the problem again in the 20,000 miles and two winters I drove the 2016.

I did the first oil change on my new 2018 yesterday. The Mishimoto can is sitting on a shelf and I won’t put it on. I really should sell it.

[fastball]

I smell another catch can argument in 3...... 2....... 1.......

[hawk02]

I had a catch can on my 2015 Silverado. In the winter months I would have to empty the darn can every 10-14 days because it would fill up with condensation. It became such a PITA that I removed the can and vowed never to put another one on any vehicle of mine again.

For those that ask why cars don't come from the factory with a catch can, this is the big reason why. I can't imagine having to tell my elderly father that he has to empty the catch can on his car every 2 weeks in the winter. Far easier to pay for an intake clean out at 30,000 miles, IMO.