Oil Catch Can on 2022 RAM 1500 5.7L HEMI (Non-eTorque) — Needed or Not?

[HEMIMANN]

Automobile manufacturers don't use catch cans for multiple reasons

-Carbon buildup from PCV blow-by is usually a long-term issue, not a “during warranty” issue. Just like them using many plastic internal parts for the engines now. Thats obviously a cost saving move also not a longevity one which brings me to the next point...

-cost savings, lower production cost

-Another thing that the EPA will want to regulate

-Typical consumer does not want to check their catch can and in some cases they need to be checked more often than every oil change
Now imagine:

• Someone never checks it
• It fills with sludge
• Freezes in winter
• Blocks PCV flow
• Blows out seals

Guess who gets blamed? The car company.
Manufacturers design cars for people who:

• Never open the hood
• Skip maintenance
• Ignore warning lights

A catch can adds owner responsibility, and that’s liability.

They absolutely could, Nick. But they won't spend the money to make it maintenance-free, unlike the more expensive stuff from Racor-Parker for big diesels that has the drain back to the crankcase from the coalescer.

In fact, Mazda has done exactly this. I haven't researched how effective it is, but at least they put a coalescer in their GDI turbo engine. It's in the schematics, you can look it up.

 

[Nick@GotExhaust]

They absolutely could, Nick. But they won't spend the money to make it maintenance-free, unlike the more expensive stuff from Racor-Parker for big diesels that has the drain back to the crankcase from the coalescer.

In fact, Mazda has done exactly this. I haven't researched how effective it is, but at least they put a coalescer in their GDI turbo engine. It's in the schematics, you can look it up.

Exactly, cost trumps all for most brands if not all. They want to hit their margins while still being competitive in their markets. They figure out any and all ways to cut costs. I have recently read into what Mazda is doing a little. I haven't had the time to deep dive it but definitely an interesting set up! The DI engines definitely need something!!

 

[Nick@GotExhaust]

In my post (#11) … I addressed some of the things you mention (re: EPA, etc)…. However, in some previous designs, both automotive, marine, and aviation, … air/oil separators simply condense and drain automatically into the sump, where the oil goes back to work….and any water is evaporated with heat.

And that is where increased cost comes to play and why its not done by the majority of the major brands. Meanwhile F150s with the Ecoboost (mostly the earlier generation) had their charged air coolers filling with oil and condensation. The fix was a a drain valve on the CAC or a catch can...

 

[Silby]

I have a 97 1500 with the 5.9. The throttle body would gunk up every few thousand miles and would have to remove air cleaner and clean throttle body. After installing the CC the throttle body stays clean. I empty the CC every oil change with about a third to half full of gunky oil. one of the best things I have installed on my truck.

I put one on my’99 Ram and it was always filling up before oil changes.
I am thinking about putting one on my’14 Ram. I actually have one of the old style, heavy plastic ones.

 

[mikeru]

Generally speaking, older engines have more blow-by. This will cause the catch can to fill up more quickly. It’s a good idea to empty a catch can monthly when you first install one on an older engine. At least until you get a handle on how quickly it fills up. Also remember that it will usually fill up quicker in winter.

I empty the one on our 2020 Limited at each oil change, which I do once per year or 5k miles. It’s never been more than half full. I empty the one on our F150 3.5 EcoBoost mid way between oil changes and it’s usually about half full.

 

[Wild one]

Every Hellcat built has a Air/Oil Seperator :aka catch can,but it drains back into the sump,where i'm not so sure it should go,as the vapor in the pcv system is also fairly acidic.
One thing they do on a naturally aspirated hemi is cut down on the throttle body cleaning,and they keep the inside of the intake manifold and intake ports a hell'va lot cleaner.
I've pulled intake manifolds off higher milege hemi's with out a catch can,and literally had oil drain out of the intake manifold when tipped on it's side.
The guys who don't believe in them have never ran one on a hemi,and odds are have never had the intake manifold off,so take whatever they say with a big grain of salt

 

[HEMIMANN]

Every Hellcat built has a Air/Oil Seperator :aka catch can,but it drains back into the sump,where i'm not so sure it should go,as the vapor in the pcv system is also fairly acidic.
One thing they do on a naturally aspirated hemi is cut down on the throttle body cleaning,and they keep the inside of the intake manifold and intake ports a hell'va lot cleaner.
I've pulled intake manifolds off higher milege hemi's with out a catch can,and literally had oil drain out of the intake manifold when tipped on it's side.
The guys who don't believe in them have never ran one on a hemi,and odds are have never had the intake manifold off,so take whatever they say with a big grain of salt

Why is blowby acidic? Not much sulfur in gasoline, is there? Certainly not like there used to be in OG diesel fuel (diesel oils had TBN's starting 12-13, ocean marine oils TBN of 70 to burn Bunker-C slop!!!)

 

[Wild one]

Why is blowby acidic? Not much sulfur in gasoline, is there? Certainly not like there used to be in OG diesel fuel (diesel oils had TBN's starting 12-13, ocean marine oils TBN of 70 to burn Bunker-C slop!!!)

Yes, the byproducts (often called blow-by gases) that are sucked through the Positive Crankcase Ventilation (PCV) system in a gasoline-powered engine are acidic.
Hot Shot's Secret +1
These gases are a mixture of combustion byproducts that escape past the piston rings into the crankcase, containing components that form acids when mixed with oil and moisture.

Key Acidic Components and Byproducts

• Nitrogen Oxides (NOx): Produced during combustion, these react with moisture to form acids.
• Water Vapor/Condensation: A natural byproduct of combustion, water combines with other contaminants to form acidic sludge.
• Unburned Fuel and Hydrocarbons: These mix with the oil, reducing its viscosity and contributing to, corrosive, acidic oil breakdown.
• Sulfur Oxides: Depending on fuel quality, these can form sulfuric acid.
  Hot Shot's Secret +4

Why the PCV System Must Remove Them
If the PCV system fails or becomes clogged, these acidic, dirty contaminants remain in the crankcase, causing significant damage:

• Engine Sludge: The acidic mixture creates a thick sludge that can block oil passages and lead to bearing failure.
• Corrosion: Acids eat away at internal engine components and contribute to the premature breakdown of motor oil.
• Varnish/Hard Deposits: The fumes condense and create hard varnish coatings on internal parts.

The primary purpose of the PCV system is to use engine vacuum to pull these acidic gases out of the crankcase and re-burn them in the combustion chamber, preventing them from contaminating the engine oil.

 

[HEMIMANN]

The gases, yes Not the liquid. The gases still pass through the coalescer.

 

[Wild one]

The gases, yes Not the liquid. The gases still pass through the coalescer.

Okay you've lost me. I thought you were referring to why the contents of the air/oil seperator shouldn't go back into the crankcase/oilpan. What are you actually talking about Brian?

 

[RamDiver]

Okay you've lost me. I thought you were referring to why the contents of the air/oil seperator shouldn't go back into the crankcase/oilpan. What are you actually talking about Brian?

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.

 

[HEMIMANN]

Okay you've lost me. I thought you were referring to why the contents of the air/oil seperator shouldn't go back into the crankcase/oilpan. What are you actually talking about Brian?

Breather coalescers are intended to return liquids to the oil sump instead of into the engine air intake. The vapor is allowed to pass into the engine air intake. Simple.

 

[Wild one]

Breather coalescers are intended to return liquids to the oil sump instead of into the engine air intake. The vapor is allowed to pass into the engine air intake. Simple.

• Unburned Fuel and Hydrocarbons: These mix with the oil, reducing its viscosity and contributing to, corrosive, acidic oil breakdown.

 

[HEMIMANN]

• Unburned Fuel and Hydrocarbons: These mix with the oil, reducing its viscosity and contributing to, corrosive, acidic oil breakdown.

shouldn't be much in an SPFI engine, esp. modern ones with the gighter tolerances than the old b*a*n*g*e*r*s we grew up with that spewed everywhere. Unless they're very old and worn out. What little there is was shown in past analysis to be mostly water.

However, it is THE problem in single injector GDI engines, worse with turbo.

 

[Wild one]

shouldn't be much in an SPFI engine, esp. modern ones with the gighter tolerances than the old b*a*n*g*e*r*s we grew up with that spewed everywhere. Unless they're very old and worn out. What little there is was shown in past analysis to be mostly water.

However, it is THE problem in single injector GDI engines, worse with turbo.

Stick your nose into a 1/2 full catch can and you can definitely smell fuel.

 

[Nick@GotExhaust]

Stick your nose into a 1/2 full catch can and you can definitely smell fuel.

Agreed, even more so with DI. I swear you can easily run a lawn mower off of what comes out of a forced induction, direct injection engine catch can.

 

[HEMIMANN]

Agreed, even more so with DI. I swear you can easily run a lawn mower off of what comes out of a forced induction, direct injection engine catch can.

Yeah, but I was talking naturally-aspirated port injection with newer motors (tight tolerances).

There is no dispute that GDI motors require breather condensate mechanism. Because OEM's aren't building in (sans Mazda), aftermarket is essential. Such as you!

 

[Bob Horowski]

Not adding to whether a catch can is needed or not but after some research I decided to install one on my '22 5.7 non-etorque. Being someone who always thinks everything can be improved I thought about the process of emptying the catch can reservoir and decided that unscrewing and recrewing the reservoir back on would prematurely wear out the threads [can is aluminum] and the o-ring would fail sooner than I wanted. So I added a drain with a shut off valve and hose emptying into a used orange juice bottle that I mounted in the space just off the radiator. Now while I'm fueling up I pop the hood and open the drain valve and empty the catch can while I nothing better to do . Back to the original question of necessary or not I don't know but I am surprised how little oil I drain out of the juice bottle between oil changes that I do at 5k miles, and IMHO I'm glad that oil was not sucked into the engine.

 

[HEMIMANN]

A number of the catch can vendors are including drain valves with their kits these days, fyi. I looked at some of these.

 

[Wild one]

A number of the catch can vendors are including drain valves with their kits these days, fyi. I looked at some of these.

That was one of the reasons why i went with Moroso cans on my 3 hemi's and old 4.7,as they were the first to have Hemi specific cans with a drain valve.
In my opinion the 4.7 needs a catch can as much or more then a hemi does