Still Not Sold On A Catch Can? Check Here...

[TRKLGND]

Don't the redesigned valve covers on the 2018s pretty much eliminate the need for the catch can?

[2018GMC]

Didn't know they were redesigned? Look the same from outside but inside design change or looks different from outside?

 

I can snap some pics of my 18 valve covers once the sun comes up.

[diyer2]

  

[TRKLGND]

1 hour ago, 2009GMC said:

Didn't know they were redesigned? Look the same from outside but inside design change or looks different from outside?

 

I can snap some pics of my 18 valve covers once the sun comes up.

I could be wrong but I thought I saw an article about the new for 2018 vavle covers for the L86 (6.2L) that separate and trap more oil than previous valve covers.  I'm looking for the article again.

[crushNchowda]

On 11/13/2018 at 1:28 PM, 300 Blackout said:

Unfortunately, objective data is limited on the impact of catch cans on build-up regardless of oil, fuel, etc... Most is based on theory and logic. That is why this debate seems to be never ending between those who swear by them and those who question their usefulness. To perform objective testing of the impact of a catch can would be quite time consuming and costly. Then to try and replicate the test changing only the variable of the oil type would be even more costly. I don’t think the info you’re looking for is out there.

 

If you’re looking for info only related to oil type without anything related to catch cans, I honestly don’t know if that info is out there.

 

Another guess - the most infamous of the carbon build up related to DI engines has been BMW products especially the N54 (?? I think) turbo 6. I'm definitely not an expert when it comes to combustion engines, but I've been a car guy all my life do a little wrenching here & there & read up quite a bit about the latest & greatest the industry has to offer, ironically I also work for a company that produces aluminum...the same AL that our engines are made from (like quite literally - in fact I've been getting the scrapped new prod. DOHC V8s to convert back to ingot - many have literally been blown up in testing @ bowling green), and I think it is really worth noting & considering the fact that the cars that seem to have the most DOCUMENTED issues w/ DI tech causing carbon buildup have been FI motors, especially turbos.

 

Turbo cars always run a bit rich on A/F ratio from the factory (most cars do as precaution - but turbos even more so) & that is especially true when they're under boost, ever seen a fuel table for subaru WRX? Combine DI w/ super rich A/F tunes + propensity to be under constant boost w/ 2 tiny snails to provide smooth acceleration/reduce turbo lag + a heavy foot by customers driving their euro sport sedans & you have a perfect recipe to result in carbon build up on the valves & cylinder heads. 

 

Food for thought: consider that - knowing they were having starting to have some issues w/ this new tech engine - BMW went from 2 small turbos on that N54 motor to a larger single turbo.....my guess is that was an effort to reduce the carbon caking issue for the scenario just played out above.

 

No this motor or something similar will be put into the next Gen Supra....as far as I know no catch can will be on that car from the factory, think Toyota would consider putting that motor in their halo of halo cars without fully testing & vetting this issue? I think not.

 

That being said - my belief is this whole concern about the carbon buildup & DI engines really starts & ends w/ BMW & FI engines utilizing this tech. If a single turbo N54 motor using DI doesn't need a factory catch can (ya really think BMW wants to be on the hook for walnut blasting every damn N54 equipped vehicle - which is like 70% of their cars lol, I don't!!) & if adjustments to the A/F ratio + throttle mapping + reduction in # of turbos & when the spool up = no more carbon issues on the motor most synonymous w/ it, then I don't feel our N/A small blocks need it, period. If a catch can was the fix and/or if the problem was that rampant, BMW WOULD BE THE COMPANY PUTTING THEM ON FROM THE FACTORY FIRST & FOREMOST!!!

 

I could care less that a high end camaro has one, so what? That's just GM appeasing the tuner crowd.

 

 

[diyer2]

Installing a catch can is a it makes me sleep good thing. 

Same as not doing extended oil change intervals.

 

 

[SS502]

Here is an interesting read...

A few tidbits from the article, and NOT meant to confirm nor deny this need or non-need for a catch can! Just information, I recommend reading the whole article:

 

There are downsides to DI (Direct Injection). A DI system is more expensive because the pressure required to squirt fuel into the combustion chamber is 50 to 100 times higher than with PI (Port Injection), and the higher-pressure pump imposes parasitic losses. Direct injectors tend to be noisy. Carbon deposits—both on the backsides of the intake valves and on tailpipes—are service issues for some DI users.

 

The ultimate strategy is combining both PI and DI benefits, using each to diminish the other’s negatives. Toyota, for example, fires both injectors during low to medium load and rpm conditions—in other words, during normal driving. This raises the density of the incoming charge without boosting and flushes carbon deposits off the intake valves.

 

Dowding and his Ford engineering colleague Stephen Russ stress that carbon deposits on tailpipes and intake valves have never been an issue in their DI engines.

 

**Toyota introduced this technology, which it calls D-4S injection, on a V-6 more than a decade ago and now uses port and direct injection on its 2.0-liter flat-four (which is built by Subaru), 3.5-liter V-6, and 5.0-liter V-8.

**Audi has it on its 3.0-liter V-6 and 5.2-liter V-10 engines.

**Ford currently is the dominant player with what it calls dual-fuel, high-pressure direct injection (DI) and lower-pressure port injection (PI).

 

As lessons are learned and component costs fall, expect more makers to adopt this approach...

 

 

https://www.caranddriver.com/news/explained-why-some-engines-have-both-port-and-direct-injection

 

 

Edited November 16, 2018 by SS502

[pronstar]

Lexus had carbon issues with their now-discontinued DI 2.5L V6, but interestingly it was more toward the early part of this engine’s life cycle.

Later versions of this engine haven’t had nearly the same level of reported issues.

Their D4S technology has been around for over a decade. But the port injectors were never initially touted as solving carbon buildup...it was more of an unannounced side benefit.

 

The initial stated reasons for D4S are a smoother idle, and better cold-start performance.

Only somewhat recently has the “cleaning” effect need touted by them. They even run a cleaning cycle through the system, to knock deposits off valves.


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Edited November 16, 2018 by pronstar

[Doublebase]

I don't understand why someone hasn't gone through the throttle body with a boroscope and taken a look at their valves...maybe someone already has? Or maybe you just can't get in there with a camera?

 

My truck is too new (2018 17,000 miles) or else I'd do it...plus I've been running a catch can for the last 5,000 miles or so (and I do cleanings every 5,000). So if my valves are "clean" is it because of the can and the cleanings, or is it just because there wouldn't be any buildup? 

 

The next time i have a high mileage Silverado in the shop I'll take a look if I can.

 

[Black02Silverado]

18 minutes ago, Doublebase said:

I don't understand why someone hasn't gone through the throttle body with a boroscope and taken a look at their valves...maybe someone already has? Or maybe you just can't get in there with a camera?

 

My truck is too new (2018 17,000 miles) or else I'd do it...plus I've been running a catch can for the last 5,000 miles or so (and I do cleanings every 5,000). So if my valves are "clean" is it because of the can and the cleanings, or is it just because there wouldn't be any buildup? 

 

The next time i have a high mileage Silverado in the shop I'll take a look if I can.

 

I say look at yours.  Since you are at a low mileage and have a CC, if you see build up then you know something isn't working like it is supposed to.  If it is clean then what you are doing is working well. 

[Doublebase]

On 11/15/2018 at 7:03 AM, elcamino said:

How do you know that what is shown in the catch can is not from normal condensation forming in the can?    To know you would have to inspect / empty the can after every drive cycle and not let it accumulate for miles and months.   Has anyone experimented like that?

The can is going to cool down much faster than the engine and is more sustainable to condensation.

When I first got my can I went through the initial...”this is exciting”, faze and I was checking it virtually every day. I found it does very much catch oil, much more oil towards the end of the oil change interval. The oil must shear or lose its ability to stick to stuff. Because it catches way more oil when you’re at the 4-5k mike mark, compared to say the 100-200 mile mark. 

 

I caught straight oil, no condensation, when it was the warmer months...now that it’s cold I’m catching a mixture of oil and condensation. I don’t think there’s a lot of condensing going on after the vehicle is allowed to cool down, I think it’s happening on initial start up when the crankcase is sitting in  cold temps and it gets sucked into the can/intake manifold.

[pronstar]

If my catch can was filling with 100% oil, I’d be concerned.



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[Doublebase]

18 hours ago, pronstar said:

If my catch can was filling with 100% oil, I’d be concerned.



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Oh I was concerned, maybe not...I need to go out and get a cat scan, concerned, but pretty concerned. Relatively new truck, purchased in April, only 17,000 miles or so on it. And it was catching oil, lots of oil. Now it was also close to the end of the oil change interval, and I was hoping that was why. After changing the oil, and since checking it, that appears to be the case. At least what I've found is that when the oil starts to get some miles on it, it tends to thin out or not stick as well/easily. There are names/explanations for both. Shearing and I can't remember the other, but at least in my case - with the catch can - it seems to be the case.

[mtkawboy]

I apologise if this has been covered but I didnt feel like reading 17 pages, what effect will below zero temps have on these cans with water & oil in them ?

[TXGREEK]

Spoke with my mechanic, told him I wanted the best Catch Can installed in my truck, he said I didn’t need one because I change the oil with synthetic to frequent to catch up with a catch can Ha!