Pcv valve

[Brahmajoe]

Has anybody changed there Pcv valve? I saw there was an update where the hole is smaller. Any reason why they did this or has anyone seen a performance difference

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[willys 41]

I am still in testing mode with the new PCV valve
I have an UPR oil catch can and have been keeping the oil that it has collected every 1000 mile
I have two containers of oil before new PCV valve and have 600 more miles to go before I check it with the new PVC valve
The one on the left is the old PCV valve
I will keep you posted on the results

 

[Jobofly]

Following

 

[willys 41]

They upgraded the PCV valve because the amount of oil mist being sucked into the engine is causing carbon build up in the combustion chamber and also causing spark knock or pre detonation
Your best defense against oil intrusion is an oil catch can
You will be amazed on the amount the oil the catch can collects

 

[JW Jeep]

Does anyone know when the pcv valve was updated to the smaller hole ? Production date ?

 

[ShadowsPapa]

Does anyone know when the pcv valve was updated to the smaller hole ? Production date ?

Probably with the 3.6 PUG and that means before Gladiator.
Otherwise, they'd not be able to simply put in the new version of the PCV in earlier Gladiators - it wouldn't fit.

Remember, for every ounce of oil you think you catch in a can, the pan level has to drop that same amount. So if you think you've caught 32 ounces of oil in 4,000 miles, your JT is a quart low or more.

Any reason why they did this or has anyone seen a performance difference

The earlier design didn't separate out the oil from the air being evacuated from the crankcase.
No other reason - and there shouldn't be any performance issues unless you had excessive oil getting into the chamber.
You can look at spark plugs to help determine what's being burned in there......

 

[willys 41]

I only herd about it about 6 months ago
This is where I first herd about it

https://www.jlwranglerforums.com/fo...-issues-pre-detonation-carbon-build-up.89553/

 

[ShadowsPapa]

mine is a June 2022 build 2022 model and it's doing just fine
they don't really give build dates.
It sure can't hurt a thing to see if you have the latest PCV in place.

Interesting how many sites - even some car sites, still use the incorrect term "pre detonation".
It's either preignition or detonation.
Preignition can lead to detonation, but there's no such event as predetonation unless one is describing the events leading up to detonation such as the extreme pressure and temperatures leading to self-ignition which is before, or "pre-detonation".

 

[Brahmajoe]

mine is a June 2022 build 2022 model and it's doing just fine
they don't really give build dates.
It sure can't hurt a thing to see if you have the latest PCV in place.

Interesting how many sites - even some car sites, still use the incorrect term "pre detonation".
It's either preignition or detonation.
Preignition can lead to detonation, but there's no such event as predetonation unless one is describing the events leading up to detonation such as the extreme pressure and temperatures leading to self-ignition which is before, or "pre-detonation".

Mine was a December 2021 build. I had the old PCV valve when I swapped it out yesterday.

 

[JW Jeep]

Mine was a December 2021 build. I had the old PCV valve when I swapped it out yesterday.

Did you have to get whole tube assembly or just valve ? The back part looks alittle hard to get at to check. Part number for valve ? My tube number is 68261200AF my production is 8/22

 

[willys 41]

Pre-Ignition:
Definition:
Pre-Ignition is the ignition of the air/fuel mixture before the spark plug fires.

A pre-ignition combustion event looks something like this…
The fuel air mixture enters the combustion chamber as the piston is on its downward intake stroke. The piston then returns upward for the compression stroke. The more compressed the mixture is, the more difficult it is to ignite it, therefore, with the piston on the low side of the compression stroke, the mixture is actually easier to ignite than when it gets closer to Top Dead Center (TDC). A hot spot in the cylinder such as a glowing spark plug tip can ignite this low compression mixture very early, before the spark plug fires. Now the upward motion of the piston is fighting the combustion force that is expanding. This adds a tremendous amount of heat and load to the engine, and for this reason pre-ignition is responsible for much higher cylinder pressures than detonation. The pressure from pre-ignition is not rapid like it is with detonation. Instead, the pressure is very high and has a much longer duration.
Damage:
Damage from pre-ignition is much more severe and instantaneous than that from detonation. Typically, with pre-ignition, you will see holes melted in pistons, spark plugs melted away, and engine failure happens pretty much immediately.
Due to the longer duration of the heat and pressure bought on by pre-ignition, you will notice a lot more melted parts, whereas, with detonation, you get more parts that are just blown apart.

 

[ShadowsPapa]

Yeah, that's what I said - and what I've posted about the two many times here, including causes of each, and more.

Preignition is ignition of the charge before the normal spark ignition.
It can be caused by improperly ground valves with edges that are too sharp, any sharp corners or edges that can get hot and glow, even carbon deposits that glow red, or a spark plug in the wrong heat range where the electrode is actually hot enough to ignite the mixture being compressed before the spark occurs.

I've written some documents on this, and some GM engineers have had some interesting insight into both events.

Carbon raises compression pressures, which can cause detonation. If the carbon glows, it could cause preignition.

We used to deal with a whole lot more carbon build-up issues than occur today. Not that it doesn't, but it's not as common as it was.

Detonation can break things. The sudden jump in pressure can blow away the boundary layer, allowing melted pistons.

Detonation damage - you can see the top of the top ring because of missing piston material ->

(the above is not from the web but from an engine I worked on in my own shop)

 

[willys 41]

Carbon build up. like described caused by oil entering the combustion chamber via pore PVC engineering and design

 

[ShadowsPapa]

Carbon build up. like described caused by oil entering the combustion chamber via pore PVC engineering and design

not in the pic I posted. It was a high compression engine (23,000 miles) and that one year was subject to detonation. (different deck height and head chamber and the piston design didn't help any)

There wasn't carbon build-up other than what was caused by the damage. So in that case, damage preceded the oil carbon build-up. That pic doesn't show carbon build-up beyond normal for the miles.

the heads were really clean, compression was not above normal.
One fellow in MN resolved most of the issues by milling a specific shape into the head apparently causing turbulence. Good quench and turbulence is important in the prevention of detonation.

 

[Brahmajoe]

Did you have to get whole tube assembly or just valve ? The back part looks alittle hard to get at to check. Part number for valve ? My tube number is 68261200AF my production is 8/22

Just the valve. My dealer had it in stock. The tube was loaded with oil and so was the old Pcv. I wish I had a new tube.

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