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6.6 - Catch Can - Final Answer

6.6HD

By 6.6HD
in 6.6L Gas V8 (L8T)

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Grumpy Bear Senior Enthusiast

Grumpy Bear

Posted
Posted (edited)
9 hours ago, CRApex said:

So problem solved, Easy GDI service and modern engine full synthetic!

 

More like problem better "understood". :) 

 

Anyone who has ever torn down a high mile carburetor motor with poor valve seals/stems has seen the backs of intake valves that are quite caked with carbon. 

 

Valve seals don't eliminate oil past the stem. They control it in concert with fit. Just like oil "CONTROL" rings don't eliminate oil into the chamber. But done well both look like no oil is being used "over a reasonable oil service period". Catch can won't help either of those causes. IN fact, nothing but a mechanical service will fix the valve stem issue. 

 

If the rings are bad enough that blowby gasses are entraining an unusual amount of oil into the PCV system, then a catch can will limit but not eliminate oil migration via that route. 

 

In a healthy motor, most of what a can catches is water vapor, fuel vapor and a nominal amount of oil mist. What oil that is entrained can be partially mitigated by choice of base oils and chemistry. Ester or ester/AN bearing oils leave less carbon on valve backs than straight up Group III/IV. 

 

I know little to nothing about these new Valvoline products. 

 

 

Edited by Grumpy Bear
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mrjulian416
mrjulian416

The passenger side tube is the "fresh air" line allowing clean, metered air a path into/out of the engine.  It is not a "foul air" line letting blowby out of the engine.  There is much higher vacuum a

It's Tim
It's Tim

Peeps are worried to death about a little engine oil in the intake manifold but seemly could less that their arteries are almost plugged solid from fat food. ?

It's Tim
It's Tim

So... this dudes an "expert" in "catch cans" but failed to notice the engine was only running on 7 cylinders multiple times? Probably time to find a different mechanic and not waste money on a snake o

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CRApex Enthusiast

CRApex

Posted
Posted (edited)
26 minutes ago, Grumpy Bear said:

 

More like problem better "understood". :) 

 

Anyone who has ever torn down a high mile carburetor motor with poor valve seals/stems has seen the backs of intake valves that are quite caked with carbon. 

 

Valve seals don't eliminate oil past the stem. They control it in concert with fit. Just like oil "CONTROL" rings don't eliminate oil into the chamber. But done well both look like no oil is being used "over a reasonable oil service period". Catch can won't help either of those causes. IN fact, nothing but a mechanical service will fix the valve stem issue. 

 

If the rings are bad enough that blowby gasses are entraining an unusual amount of oil into the PCV system, then a catch can will limit but in eliminate oil migration via that route. 

 

In a healthy motor most of what a can catches is water vapor, fuel vapor and a nominal amount of oil mist. What oil that is entrained can be partially mitigated by choice of base oils and chemistry. Ester or ester/AN bearing oils leave less carbon on valve backs than straight up Group III/IV. 

 

I know little to nothing about these new Valvoline products. 

 

 

I thought the Valvoline article was informative, was just poking fun of how they sum it up with the Instant oil change GDI service and full modern synthetic oil as the solution.  That said, I too know little to nothing about the new Valvoline products so maybe the laughs on me??

Edited by CRApex
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lineman1234 Enthusiast

lineman1234

Posted
Posted

OK, so as mentioned, this is ( just ) and experiment for me. This added, will be all i have till it fully warms up hear and or when i try non ethanol fuel at 87 octane. A full tank full when i stumble across it hear in the northern midwest. 

...

For the heck of it, yesterday i went to install a added catch can on the passengers side. In all ( there ) wisdom, the connectors and plastic hose isnt the same as the drivers side. So no can installation. 

... Today, i took a couple Q-tips and went for a look into iffff, anything did or does go between the passengers side front valve cover and the intake. 

... As of about 5,700 miles on my 2024 L8T,,, nothing. 

... 

Every one likes pics. the first pic is the plastic pipe that goes between the intake and passengers side valve cover. Next pic is the 2 ports or spots it plugs into. Next pic is it and 2 Q-tips i swabbed the intake and valve cover as well as the pipe, as far as i could with the said Q-tips. Nothing. 

... The same 44 mile trip today with an empty can, on the drivers side,,,  resulted in about a teaspoon of oily water vs the other times about 1.5 tablespoons. It was 50-55 today vs the other times 20-30, so seems temp plays a part in the can. 

20240401_110936.jpg

20240401_110847.jpg

20240401_110836.jpg

Pryme Senior Enthusiast

Pryme

Posted
Posted
15 hours ago, lineman1234 said:

OK, so as mentioned, this is ( just ) and experiment for me. This added, will be all i have till it fully warms up hear and or when i try non ethanol fuel at 87 octane. A full tank full when i stumble across it hear in the northern midwest. 

...

For the heck of it, yesterday i went to install a added catch can on the passengers side. In all ( there ) wisdom, the connectors and plastic hose isnt the same as the drivers side. So no can installation. 

... Today, i took a couple Q-tips and went for a look into iffff, anything did or does go between the passengers side front valve cover and the intake. 

... As of about 5,700 miles on my 2024 L8T,,, nothing. 

... 

Every one likes pics. the first pic is the plastic pipe that goes between the intake and passengers side valve cover. Next pic is the 2 ports or spots it plugs into. Next pic is it and 2 Q-tips i swabbed the intake and valve cover as well as the pipe, as far as i could with the said Q-tips. Nothing. 

... The same 44 mile trip today with an empty can, on the drivers side,,,  resulted in about a teaspoon of oily water vs the other times about 1.5 tablespoons. It was 50-55 today vs the other times 20-30, so seems temp plays a part in the can. 

20240401_110936.jpg

20240401_110847.jpg

20240401_110836.jpg

Seems your truck is running as intended. 
 

if you start swabbing inside your exhaust you will probably get some soot residue in there. Doesn’t mean anything. 
 

internal combustion engines are messy. 
 

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lineman1234 Enthusiast

lineman1234

Posted
Posted

No, no, this summer im going to take flat black paint and do this.... So i can hang with the non cool people. 

20201222_161008.jpg

  • Haha 1

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