[B. C.]

Interesting theory. Never thought of that. I don’t know if there would be enough oil vapors to actually do what’s pictured.

Also, there’s another hose on the driver’s side cylinder head. Just no PCV valve. And the other end of that hose (“make-up air hose”) leads into the air filter box. Why wouldn’t there be any similar signs (oil residue) on the driver’s side cylinder head? I am pretty sure that hose is pulling blow by just like the PCV hose.

If the breather hose on the opposite valve cover wasn't there then the entire crankcase would be under vacuum which isn't a good thing. Under hard acceleration the engine is producing no usable vacuum but is still producing small amounts of blowby. The engine crankcase vapors theoretically go out the open hose and into the air cleaner box and eventually are pulled through the engine intake.

If everything in the engine is good, then it would be difficult to say that the residue on the head is an issue or a concern.

 

[TerryC6]

Interesting theory. Never thought of that. I don’t know if there would be enough oil vapors to actually do what’s pictured.

Also, there’s another hose on the driver’s side cylinder head. Just no PCV valve. And the other end of that hose (“make-up air hose”) leads into the air filter box. Why wouldn’t there be any similar signs (oil residue) on the driver’s side cylinder head? I am pretty sure that hose is pulling blow by just like the PCV hose.

In a properly working system most of the time air is being pulled into the drivers side valve cover, down through the engine into the passenger side valve cover, out through the PVC and into the intake plenum. But there are time when a vacuum is not present and those gasses will take the path of least resistance. This is why you see a little residue on the air filter from time to time.

And the vapors are not in fact oil vapors but are made up of water, gasoline, oil and acids that result with this concoction. Gasoline and water are introduced to the crankcase during the combustion cycle as blowby. Remember for every 1 gallon of gasoline burn 1 gallon of water is produced.

 

[JeepCares]

Interesting theory. Never thought of that. I don’t know if there would be enough oil vapors to actually do what’s pictured.

Also, there’s another hose on the driver’s side cylinder head. Just no PCV valve. And the other end of that hose (“make-up air hose”) leads into the air filter box. Why wouldn’t there be any similar signs (oil residue) on the driver’s side cylinder head? I am pretty sure that hose is pulling blow by just like the PCV hose.

Of course, H3br3wHamm3r!

Rob
Jeep Cares

 

[dmulk]

Soooo....what's the story on the timing chain ordeal? Inquiring minds....🤓

 

[H3br3wHamm3r]

Soooo....what's the story on the timing chain ordeal? Inquiring minds....🤓

Started with replacing the oil filter housing and couple other gaskets and seals on the top side, like valve cover gaskets. During that, I also decided to re-loom the wiring harness because it was starting to disintegrate. After putting everything back together, I had (unknown to me at the time) swapped the passenger side camshaft VVT solenoid connectors. And yep, it's possible.

That caused a DTC or two. I thought that maybe the timing chain had skipped a tooth because I had the Jeep without oil for week and a half as I took my time doing the loom and other repairs (benefit of working from home).

Well, to ensure it didn't jump teeth, I decided to replace the timing chain (while I had the timing cover off, because no better time to do it).

So, timing chain was fine. Ended up being the swapped connectors.

 

[dmulk]

Thank for explaining. Yeah I've certainly travelled those types of journeys. The other benefits are that you know it's done right and you now have the experience and thus more confidence in the platform along with sorting future issues out with the platform on your own or in a pinch. 👍🏻👍🏻🤓