A case for catch cans

I have never been a fan of catch cans as they can cause problems if not designed properly with care taken to make sure that crankcase pressure is not elevated to a harmful level. However, after reading this article, I am thinking that there may actually be good reason to investigate catch cans and perhaps integrate one into my engine. The following article builds a strong case for catch cans.

New wave menace: How LSPI threatens modern engines (msn.com)

 

^Why? The 1GR is too ancient to have direct injection. Any oil vapors are constantly washed away by the port injectors. A catch can could mitigate oil pooling on steep inclines off-road, and that's enough reason for me to get one. There's no need to invent other reasons.

 

Maybe get an oil analysis first.

 

I don’t think we’ve seen a trend of anything that catch cans would improve over the lifespan of these engines.

Funnily enough, I don’t think catch cans are necessary on Hyundai/Kia DI-only 4-cylinders because the engine will likely die of other causes first.

As for the others, I wonder if a consensus has come together for Honda’s 3.5, Nissan’s 3.8 DI V6. I have friends with DI Honda four cylinders and carbon buildup or anything hasn’t reared its head yet at 120k+ miles. Currently in my head it’s a “walnut blast whenever it shows up” maintenance item.

 

A solution in search of a problem.

 

Blow-by is a serious problem for some engines, especially if they use direct injection as it results in intake valve sludge. Blow-by usually more prevalent in engines that use forced induction (turbo and supercharged). Blow-by is also more likely when manufacturer switches to a thinner oil without adjusting the ring design (e.g., going to 0w16 with engine designed for 0w20). Blow-by is not linear, it increases as engine oil get miles, so it is more likely to manifest at the end of the extended oil change intervals. You can mitigate mild cases of blow-by by changing engine oil more frequently. In my experience, engines have different levels of blow-by depending on oil brand you use. In my case, for a Subaru 2.5L NA engine I have significant blow-by using 0w20 Mobile 1 Synthetic but almost none using 0w20 Pennzoil Platinum. Catch can is a stop-gap solution to try mitigate negative effects of blow-by by removing such oil before gasses containing oil vapors get recirculated (and produce deposits). By far more effective solution to blow-by is to step up oil viscosity, so it doesn't happen in the first place.

5th Gen 4Runners are not known to have blow-by unless there is a mechanical issue, you don't need catch can. Additionally, the harmful effects of blow-by are minimal, as port injection design prevents intake sludge. More so, you can easily add a can of Sea Foam to a tank of premium gas and ensure that intake stays clean.

 

Are you running forced induction?



A catch can,.... on a NA 4.0 liter.... Man you have a ton of spare time on your hands. Id like to get some from ya please.

EDIT- "modern engine" the 15 year old plus 4.0....
LOLOLololololololoolllolll Now that, is comedy.

 

"modern"

 

From the article..

The recently discovered phenomenon is termed low-speed pre-ignition (LSPI), also known as super knock.

What is LSPI and where does it come from?
The official response from the industry (mainly oil companies and additive manufacturers) to this question is roughly that LSPI is uncontrolled, accidental detonations resulting from the ignition of oil particles entering the cylinders, carbon deposits, etc. Anything that can ignite and end up in the cylinder is the cause of LSPI. It occurs mainly at low RPMs and high load when the cylinder is filled with the fuel-air mixture and the moment of ignition is approaching. At higher RPMs, the same phenomenon is called SPI.

 

^You're a bit late with this; 5th gen production has ended after 15 years and ~2 million built.

 

This is a description of a phenomenon. Is it supposed to be evidence that the phenomenon occurs with any significant frequency and impact on the 4R engine?

 

I run a J&L can just to keep the intake manifold clean. I get about 4oz of oil every oil change.

 

Thanks for that explanation. Why does blow by increase as the oil gets more miles?

ETA: don’t we have a helpful bunch of anal retentives on this board doing oil analysis? Wouldn’t the oil analysis reveal the presence of blow by? Maybe those guys could review their oil reports and share with the rest of us.

 

I’m not even sure it’s even describing anything other than plain old detonation/preignition. Low rpm with high load has always been known as the classical conditions for pre-ignition.

It says excess fuel is also a cause, which is weird, because excess fuel cools the combustion chamber. Usually it’s an overly lean fuel mix that creates the higher temps necessary to trigger detonation before reaching top dead center.

I also find it funny that the article states that when “LSPI” happens at higher RPMs it’s called “SPI”. Lol…. So, industry experts call it “speed pre-ignition”? Yeah, sure. That sounds like a goofy language mistake you see on Chatbot written articles.

 

I had a Subaru that ended up part of recall over excessive oil burning. The culprit was scraper ring design. As I was closely monitoring oil level, I noticed that first 1000 miles after oil change there would be a significantly less oil burning and then it would ramp up. Dealerships knew that and would do oil consumption test after oil change to deny repairs to people right at the cutoff of eligibility. As to why this is the case - no idea. I could not see anything change in the oil analysis and they were not using any special additives.

 

Not too late for me, as I just got a 2024. It's new information for my inquisitive mind, not that I would take any action regarding it.

 

I'm going to venture a guess. As oil becomes diluted by fuel leak down past rings, oil is thinner which increases blow by. See, I can make up s^^t too.

 

Lucky 5th gen 4runner don't have any of those things the article talks about. No turbo charging, no direct injection, no nothing...

 

Waste of time in my opinion, your runner will go 500k miles plus just regular maintenance. Don't fix it if it's not broken

 

I mean…subaru.

 

The catch can can't be 100% efficient, so some undetermined amount greater than 4oz would be going into the intake without it. Seems like the can isn't such a bad idea.

 

Hegelian dialectic, weeeeeeeeeeeeeeee!!!

 

Okay. I read the whole Wikipedia page on Hegel and there’s so much going on with his philosophical doings that I can’t determine the relevance. Can you explain in laymen’s terms what you mean? (Don’t teach me to fish. Just give me the fish please!)

 

Well, he works for United Airlines, so...

I USED to, just got tired of being used, abused and being stolen from so I left. That also means I never fly on them either.

 

Those having a solution that benefits them, create a problem 1st. Then, miraculously, the best solution is theirs. Not unlike the 'Patriot Act' already waiting in the wings before 9/11.

 

Me either since I know how the sausage is made. Delta, please...

 

You are very correct about that. Part of the plan all along.

 

I work in corporate aviation now. Way better. No longer am I a "number" and expendable.