To Catch Can or Not to Catch Can

[PuddleJumper]

I see lots of people running catch cans. The way i was brought up and taught about cars was that boosted cars and Direct Injection engine cars needed catch cans and Port Injection and a lot of NA cars didn't. I know the 3.6 is Port injection, so she keeps her valves clean, and she may be up there in compression but not boosted. One would figure the PCV valve would catch any oil and that would be all thats needed. However I've seen the oil amount some have been catching and Holy Moly Batman! Where's that all coming from!? Normally i wouldn't worry but that much oil has got to kill the octane rating of any gas it mixes with right? When are first got my Mojave, 0 odo mind you, She was a peppy gal. Broke tires loose everytime you stepped on it from a stop, accelerated pretty well for sub 300. Now she barely chirps a tire unless its wet. I know the truck learns to drive based of user input over time and I have Pedal Monster on the way. But that can't be the only culprit right? Would too much oil venting into the intake also contribute to my lost pep? I'm attributing my lost 19 mpg avg to still being on winter blend gas. Thoughts?

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[James H]

I've been running a catch can since the beginning (50k miles ago). The can is a cheap, Amazon one with a 300 ml capacity. It's about 1/3 full when I check it every 3k miles. I can't say whether or not it improves performance, but it has kept a lot of crap from gunking up the intake.

 

[SRO]

There's not enough oil droplets to significantly effect your octane unless something is seriously wrong, but you may want one for other reasons. Using James H example- he gets 100ml of oil per 3k miles. Figure 18mpg- which makes 167 gallons of gas. There are ~3785ml in a gal of gas, so 100ml per 632095ml of gas (or a ratio 1 to 6321) if I'm doing my math right- so definitely not an octane hit.

I use one in my Challenger but I don't in my Jeep. It does keep a lot of crap that may coke up somewhere out of the system. It certainly doesn't hurt to have one as long as you keep up on it. Some percentage of what i pull out of my catch can is water and fuel.

 

[PuddleJumper]

There's not enough oil droplets to significantly effect your octane unless something is seriously wrong, but you may want one for other reasons. Using James H example- he gets 100ml of oil per 3k miles. Figure 18mpg- which makes 167 gallons of gas. There are ~3785ml in a gal of gas, so 100ml per 632095ml of gas (or a ratio 1 to 6321) if I'm doing my math right- so definitely not an octane hit.

I use one in my Challenger but I don't in my Jeep. It does keep a lot of crap that may coke up somewhere out of the system. It certainly doesn't hurt to have one as long as you keep up on it. Some percentage of what i pull out of my catch can is water and fuel.

ah that sounds good to me. I'll leave it be for now.

 

[DiehardTory]

I'm All in on the The Can.. Ripp on both 21 Mojave and 13 JKU.. JKU has 110K and OE PCV.. Empty every other oil change 12K miles.. PCV is bitch to replaced and clearly the PCV is DOA. Mojave not that frequent/full .. do it every other change too.

 

[Lunentucker]

You've already seen my results.
I can't see where keeping that crap out does any harm.
That said, if I do have an engine warranty claim, I'll swap the OEM line back on it before taking it in, because they love to look for an excuse to bail on a warranty.

 

[PuddleJumper]

You've already seen my results.
I can't see where keeping that crap out does any harm.
That said, if I do have an engine warranty claim, I'll swap the OEM line back on it before taking it in, because they love to look for an excuse to bail on a warranty.

Oh thats true. Yours looked super simple. I'll throw it in my cart and get to it eventually. Can't hurt but idk if i could say its definitively needed.

 

[LouisvEarlleJT]

These motors don’t need a catch can. There’s a whole long thread on it. If you’re actually getting significant oil blow-by then you have other problems.

If pressing the pedal harder doesn’t break your tires loose then a pedal commander isn’t going to either.

 

[ChrisNLA]

My direction injection Camaro had one, and my turbo Chevy truck I am building will have one.

The Gladiator isn't getting one. It's port injection, should be fine - but I won't try to talk anyone else into or out of one if they want it for their truck.

 

[PuddleJumper]

These motors don’t need a catch can. There’s a whole long thread on it. If you’re actually getting significant oil blow-by then you have other problems.

If pressing the pedal harder doesn’t break your tires loose then a pedal commander isn’t going to either.

I hear ya on the catch can part. The pedal monster part I guess I should explain further. I know it doesn’t add power. But it actually does affect the whether you snap the rear loose. First note is that the vehicle has done so easily before and now does not. The only way to get it to do so again is when I program a different tires size. This resets the self learned mapping for the throttle input, and changes shift points. Remember the truck is always trying maximize efficiency the way it’s programmed. A pedal monster would function in place as linear and set profile for throttle input. So rather than the truck managing throttle input itself regardless of how hard or fast you depress the pedal, it will now have a linear percentage match. ie 10 percent depress with your foot will mean 10 percent open at throttle body immediately. The prevention of gradual managed opening of the throttle body, would indeed make it easier to do stupid shit. The torque is there, it always has been. It’s just programmed to give it to you gradually and it learns and optimizes overtime to get more efficient at doing so. Take offroad plus for example, if u have it. Technically speaking your in 4hi or 4LO, but let’s say hi for this. You now have to rotate more mass and your on a looser surface generally. So logic would state you’ll take off slower and more sluggish than you would on the street in 2hi. Except you don’t, it fuckin scoots like it’s ass in on fire. Why? Because the throttle mapping and shift point are drastically changed in offroad plus, that’s the whole point of the feature. So it gives you all it has with minimal nanny input and off you go. And yes I left TC and ESC out of this, that was for ease of explanation. I drive with TC stage one turned off. I can drive with ABS, ESC, TC all turned 100% off. It still doesn’t pull as hard as it does in Offroad plus or when tire size has been reset. So all in all, mapping issue, if that makes sense.

I plan on doing a review of it when I get it in. And part of it will be does it make breaking the tires off the line a choice and not a request.

 

[PuddleJumper]

My direction injection Camaro had one, and my turbo Chevy truck I am building will have one.

The Gladiator isn't getting one. It's port injection, should be fine - but I won't try to talk anyone else into or out of one if they want it for their truck.

Crazy thing. My mini was direct injection and turbo. And if you put on a catch can it caused hella issues. Manufacturer stated 10-15k the intake ports and manifold had to be walnut blasted clean. Weird ass engineering on that thing.

 

[KrashEd]

I run a catch can (J&L) and it does effectively keep a fair amount of crap from recirculating back into intake tract. I also have forced-induction, so I don't want that gunk on my charge air cooler. That's important for good thermal xfer and if I end up operating at an extreme angle where oil tends to dump into the PCV... fluid doesnt compress well and you get malice in the combustion palace. Anyway, I'm good with having it after seeing that it does help.

My wife had an R56 that we did a catch can on and always had good results with that/no issues.

 

[Maximus Gladius]

Op, if I’m understanding correctly, your performance measure is in being able to “chirp” the tires so under the same conditions now, you can’t so you have a peddle monster coming and considering an oil catch can.

I think there’s a few factors to consider if you’re experiencing the “factory performance” has diminished some. I’m speculating here but if I was concerned just like you, I would be looking at these points.

1. gas that’s either summer or winter blend might effect this??
2. Do you have blow by? Turn on your engine and take off your oil fill cap. Do you feel a rush of air blowing out? If yes, you should install a catch can. If no, then there’s no oil particles being tossed into your air intake tube from the PCV and a can isn’t needed.
3. If your answer to blow by is YES , you need to pull your mass air flow sensor (it’s on the intake tube just before the bend, facing the front with two wires) and spray it off with MAF sensor cleaner. Don’t use brake clean and don’t wipe it or touch the sensor prong with a rag. Spray clean it and put it back in.
If your answer is NO, do the cleaning anyway at every oil change.
4. How’s your air filter?
5. You mentioned the thing about the computer “learning” how you drive. If your not chirping the tires every time you take off, it’s learning you don’t need that performance.

That’s my practice and I can “chirp” my tires all day long but I don’t because I’m old and mature and don’t need to impress the girls. I got mine already and if I was to do a chirp or brake stand, I’d get a smack upside the head or I’d probably break something.

 

[HorsesRear]

I wonder why the auto manufactures don't install them at the factory.

 

[PuddleJumper]

Op, if I’m understanding correctly, your performance measure is in being able to “chirp” the tires so under the same conditions now, you can’t so you have a peddle monster coming and considering an oil catch can.

I think there’s a few factors to consider if you’re experiencing the “factory performance” has diminished some. I’m speculating here but if I was concerned just like you, I would be looking at these points.

1. gas that’s either summer or winter blend might effect this??
2. Do you have blow by? Turn on your engine and take off your oil fill cap. Do you feel a rush of air blowing out? If yes, you should install a catch can. If no, then there’s no oil particles being tossed into your air intake tube from the PCV and a can isn’t needed.
3. If your answer to blow by is YES , you need to pull your mass air flow sensor (it’s on the intake tube just before the bend, facing the front with two wires) and spray it off with MAF sensor cleaner. Don’t use brake clean and don’t wipe it or touch the sensor prong with a rag. Spray clean it and put it back in.
If your answer is NO, do the cleaning anyway at every oil change.
4. How’s your air filter?
5. You mentioned the thing about the computer “learning” how you drive. If your not chirping the tires every time you take off, it’s learning you don’t need that performance.

That’s my practice and I can “chirp” my tires all day long but I don’t because I’m old and mature and don’t need to impress the girls. I got mine already and if I was to do a chirp or brake stand, I’d get a smack upside the head or I’d probably break something.

Hmmm, noted. I'll give all that a go and get back to ya. Thanks

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