Catch Can Latte (3 Viewers)

[Tachycardic]

Hi All. I installed new O2 sensors in my '94 and wrapped the headers with DEI titanium exhaust wrap because I wanted to try it. Truck runs subjectively smoother than prior, idling at 600-700rpms, but I'm getting random CELs. The Toyocom tells me that I'm running lean. The CELs occur 50% of the time and usually turn off on the highway. After 2 tanks of gas, I'm achieving 15.5/18mpg city/highway. The catch can is trapping latte-colored oil and about 2x more per miles driven than before the O2 sensor change/header wrap. The catch can used to trap black oil. Is this something to worry about? Should I get rid of the header wrap? Thanks.

 

[baldilocks]

The oil does look concerning. I would do an oil change in order to see what comes from the crank case and also send a sample to Black Stone Labs for analysis. Is your radiator/recovery tank low? If so, you might yank the spark plugs to inspect for any that look cleaner than the others. I’m trying hard not to say IT…

 

[Tachycardic]

I actually thought I blew a head gasket and was expecting the underside of the oil cap to be milky like what's in the catch can, but it was clean. I did an oil change about 900 miles ago and it still looks fresh. Admittedly, I only dipped my finger in there and looked at it--perhaps I'll do the oil analysis. Not saying that it's not the HG, but it was done at 271k (along with the spark plugs and wires) and I'm sitting at 295k, so I'm thinking that the odds are in my favor that it's intact.

I'm going to jinx myself now, but I have to ask...do HGs fail spontaneously, or do they fail a little at a time until it gives out completely?

 

[Marvelicious]

Just speculating, but I would imagine the latte is no more oil than you were getting before, it's just whipped into an oil/water emulsion now and takes up more space. The question is where is the water coming from. I don't know why you'd have a HG failure after so few miles unless the job was just poorly done, but I would get the oil analysis done for sure. Either it's something else, or you have the data to have a very pointed conversation with whoever did your headgasket.

 

[baldilocks]

I actually thought I blew a head gasket and was expecting the underside of the oil cap to be milky like what's in the catch can, but it was clean. I did an oil change about 900 miles ago and it still looks fresh. Admittedly, I only dipped my finger in there and looked at it--perhaps I'll do the oil analysis. Not saying that it's not the HG, but it was done at 271k (along with the spark plugs and wires) and I'm sitting at 295k, so I'm thinking that the odds are in my favor that it's intact.

I'm going to jinx myself now, but I have to ask...do HGs fail spontaneously, or do they fail a little at a time until it gives out completely?

A HG can fail suddenly or a little at time. That oil in the catch can does have water mixed in. I’d pull the spark pugs and maybe do a compression test as these are simple. I don’t think header wrap will cause the engine to run lean.

 

[mudgudgeon]

ask...do HGs fail spontaneously, or do they fail a little at a time until it gives out completely?

They fail a little at a time, until they spontaneously let go completely.

Or, they could fail from a single over-heat event

 

[Tachycardic]

Just speculating, but I would imagine the latte is no more oil than you were getting before, it's just whipped into an oil/water emulsion now and takes up more space. The question is where is the water coming from. I don't know why you'd have a HG failure after so few miles unless the job was just poorly done, but I would get the oil analysis done for sure. Either it's something else, or you have the data to have a very pointed conversation with whoever did your headgasket.

I'm not sure where the water is coming from either. I'm running Toyota red. It has been raining a lot here and while I've gone through lots of puddles, I don't think that it was sucked in by the intake. I'll just see what the oil analysis says.

 

[LandLocked93]

I get 'the snot' in the can on short trips (likely just condensation), but it's never whipped into a froth like yours.
On longer runs, like a trail run, I get only black liquid.
I notice that the bottom valve on yours is not RTV'd shut. That valve opens on vacuum. Or at least mine would if it weren't RTV'd shut. This will allow air into the can from the bottom when enough vacuum is pulled through the hoses attached thereto.
Perhaps for various reasons there is more vacuum happening now than before and is bringing air into the can causing the mix.
You could, once the engine is warm, observe what happens inside the can while manually operating the throttle from idle to a couple thousand RPM.
I see a brief white mist in my can when I do it.

 

[effjay80]

When I only take short trips for awhile I get the frothy buildup too.

 

[LandLocked93]

I’m trying hard not to say IT…

I thought you did well not saying IT.

 

[mudgudgeon]

I thought you did well not saying IT.

Don't say IT 3 times in a row whatever you do!!

 

[LandLocked93]

Don't say IT 3 times in a row whatever you do!!

I could **IT a better president.
I could **IT a better president.
I could **IT a better president.
Oh wait! That is definitely not what you meant.


My mistake.




1/3rd of a fifth in ... taking crickets as confirmation.

 

[mudgudgeon]

1/3rd of a fifth in ... taking crickets as confirmation.

God Dang if that aint purely American way to say your drunk, no idea what is.

 

[LandLocked93]

God Dang if that aint purely American way to say your drunk, no idea what is.

It adheres to accepted grammar norms.

What. lol

 

[thatcabledude]

Did you have that catch can thing installed this time last year?

 

[Godwin]

I'm not familiar with how these catch cans are plumbed in so my answer may be way off, perhaps this is nothing more than an increase in trapped atmospheric condensation and not a serious engine issue. Change of season, more humid days, something like that.

 

[thatcabledude]

I'm not familiar with how these catch cans are plumbed in so my answer may be way off, perhaps this is nothing more than an increase in trapped atmospheric condensation and not a serious engine issue. Change of season, more humid days, something like that.

That’s my guess.

 

[Marvelicious]

It's probably no coincidence that this came up in fall. I tend to think you guys are most likely correct, but an oil test is cheap peace of mind.

 

[Tachycardic]

Did you have that catch can thing installed this time last year?

Yes, I've had the catch can for the past 4 years. It always trapped dark and thick oil--like molasses, but thinner.

 

[Tachycardic]

I get 'the snot' in the can on short trips (likely just condensation), but it's never whipped into a froth like yours.
On longer runs, like a trail run, I get only black liquid.
I notice that the bottom valve on yours is not RTV'd shut. That valve opens on vacuum. Or at least mine would if it weren't RTV'd shut. This will allow air into the can from the bottom when enough vacuum is pulled through the hoses attached thereto.
Perhaps for various reasons there is more vacuum happening now than before and is bringing air into the can causing the mix.
You could, once the engine is warm, observe what happens inside the can while manually operating the throttle from idle to a couple thousand RPM.
I see a brief white mist in my can when I do it.

There is no valve on the bottom. It's just a way to empty the catch can without unscrewing the actual clear plastic can. It's got an o-ring and the red screw.