SquireSCA

Was just part of the package deal that I negotiated with them when I bought it. I wanted a spray in bed liner, upgrade the cloth seats to leather, 2.25" level kit installed up front and 3" blocks in the back, upgrade the tires to 1 size larger than stock, Nitto Ridgegrapplers, etc...

I have the dealer do all the work, as oil changes are included every 5k miles till 40k... but I guess I can remove the catch can for when I go in... will take 5 min to return things to stock... for the intake valve cleaning... pay the dealer to do it, or do the Seafoam kit myself?

Where do you get the OEM connectors? Would make it easy I guess, just in case.

Why the concern if the dealer sees it?

I have 4 cyl mode disabled with my tune.

That makes sense, but I am not an automotive mechanic, just a mechanically minded person, so I can't say for sure... but yeah, I think that a little vacuum would be fine, to draw a little pressure and vapor out, but it doesn't need to be so strong that it's literally sucking oil out of the case... I went literally 20 miles and there was a quarter teaspoon... That's insane. There is no reason or need for that.

Correct, and I am thinking that it's the massive suction from that line, from the intake manifold, that is drawing the oil out more than it being pushed out. When I complete my 1,000 mile test with the catch can, I will see exactly how many mL of oil is in there. I will then take the vacuum line off of the catch can and plug it, and then put a pod filter on the "out" of the catch can, drive another 1,000 miles and see how much oil it captures and compare.

I think that there wouldn't be so much oil in there if there wasn't such a strong vacuum sucking it out of the crank case... Pull the dipstick on the catch can while the engine is idling and you will hear and feel how strong that suction is... I am betting that if you capped the vacuum line going to the manifold, and just put a pod filter on the "out" line on the catch can, the amount of oil caught would go down drastically. I don't think that the amount that is "pushing out" under crankcase pressure, is anywhere near as much as how much is being sucked out by that vacuum line... Thoughts?

I posted a pic, as well as a link to the install video. There is a line coming out of the top of the case, below the throttle body. That line ran from there to the intake. I checked to see which line was pulling the vacuum and it matched what the video instructions showed.

Also, unscrew the bottom from the top, and then unscrew the little baffle from the inside of the top. Stuff some stainless steel wool in there and then out the baffle back in, and then the bottom back on. That extra material will help filter the oil out of the air, forming larger drops that will fall into the baffle and settle out, and less being passed through to the vacuum line. it won’t catch all, but removing 80-90% is well worth the $30...

How does GM not address this? I mean, how do they think dumping a full quart of oil into the intake manifold every 5k miles, isn’t gonna make problems?

Will probably have the dealer do the valve cleaning service, and if I keep up with the catch can, shouldn't have to worry about the valves getting ganked up...

This was after only 20 miles...

With the amount of oil I see in that lower hose, I think putting a filter on it might drip oil everywhere... although you could attach a hose to it and mount a filter a couple feet away, as high up as possible and that would probably mitigate any mess. but with decent catch cans being $30 shipped from Amazon, no reason not to have one.

My dealer does the BG valve cleaning service, so I will have them do that the next oil change. I will check the catch can every week or so and so long as it’s removing most of the oil, I won’t worry too much about it once the valves have been cleaned.

Yeah, I see people filling it with stainless steel wool... might keep the stuff from sloshing around and filter better, but would also require you to empty it more often, it taking up space and displacing oil and water...

I guess there is no harm in putting a catch can on those as well.

So you knew this all along, and felt the need to not say anything? That’s helpful.

Yeah, I totally had this wrong. What is scary is that nobody reading all this, caught it either! LOL Anyway, put the valve vent hoses back on the intake tube where they belong. They are drawing air OUT of the intake tube, not depositing hot oily air into it. The PCV hose is a single, short hose that comes from the top of the case, below the intake tube, and routes to the driver side of the motor, into the side of the intake manifold. I have pics of the catch can mounted with the hoses, and I marked the hoses with green and red arrows, so you can see the direction the air flows...

I think that we have been looking at this all wrong? Those two lines coming off of the valve covers, are not the crankcase vents? Those are part of the emissions where the exhaust manifold draws a vacuum and this sucks in fresh filtered air from the intake tube, and inserts it into the exhaust in order to "clean up" emissions. Most of my motorcycles over the years have had suck a thing, called the "PAIR" or "SAI" system... That's not what is putting oil into the intake. There is a second system down lower, a single line as you can see in this video:

So after even 100 miles, there isn't even a drop of oil in the catch can. There isn't even a slightly oil residue in there, which seemed odd. So I unplugged the hoses from the catch can, started the car and had my wife give it some throttle... The two plugs coming out of the valve covers... Those are actually drawing a vacuum at idle. There is no pressure coming out of them. As she revved the motor up you could feel some slight pulses in them, but they still seemed to be drawing a slight vacuum, rather than pushing any pressure. How is that? Where is that vacuum coming from? If that is the case, how would oil make it's way through that hose and into the intake manifold, which also, at 3,000rpm didn't seem to be drawing a vacuum. Now maybe at high revs it does, and the hoses coming off the valve covers reverse from a vacuum and do push a little pressure that the intake sucks up... But my 100 road miles... I tend to drive with a lead foot. I did the exhaust, intake mod, higher flow filter, Airaid MIT, SuperChips 93 octane performance tune with throttle sensitivity increased by 20%, etc... I have been hard on the gas to redline just to see if it would blow any oil into there, and it hasn't, not in the catch can... Anyone have any insight on this? Is it possible that the 18 models work differently than others?

That occured to me as well, and I will address that if I reinstall them, by finding some short, 90 degree hoses to bridge the filters to the crank vent ports. I want to use the stock quick-disconnect plugs for easy removal, inspection and cleaning from time to time.

So here has what I have done, as a test. I bought a cheap catch-can off of Amazon, and installed it. I will drive the truck as I normally do, for 1,000 miles and then check to see how much oil is in there. If little to nothing, then I will go back to the vent filters and not worry about it. If it catches a good amount of oil, then I will know that using the vent filters would likely have dribbled oil onto the motor and made a bit of a mess. Either way, it is not using the intake vacuum to draw in the crankcase vapors, giving me the worst case scenario for pulling oil out of there... If it barely pulls any, the filters will be fine. If it's a lot, then the catch can stays. Either way my valves won't be getting any more oil baked onto them, so its a win either way.

For those that know more about this stuff than I do... My motorcycles have these systems, but they route the crankcase vent tube to the airbox, BEFORE the air filter... usually at the bottom, so while you might get a little bit collecting down there, it really has no way to get sucked up and through the air filter and into the motor... Would that be an option? To simply get longer hoses, tap a connector into the bottom of the airbox, and get it before the filter in an area not likely to get sucked into the motor itself, while still getting some of the benefit of that vacuum to pull the crankcase vapors out?