6.6 - Catch Can - Final Answer

Grumpy Bear · March 31

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 March 31 by Grumpy Bear

CRApex · March 31

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 March 31 by CRApex

lineman1234 · April 1

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.

Pryme · April 2

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.