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Discussion Starter #1
As I was preparing to replace the spark plugs on my HEMI I removed the plastic cover and spotted this part that seemed to have leaked oil and I couldn't figure out what it is. It has a cap on the top part with a "lock" position. Not sure where it started leaking from but it appears to have leaked a decent amount.

Does anyone know what part is that on the pic? It's located right above the passenger side top of the motor. Should I be concerned? Does it need to be fixed? Thanks!
 

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is it the pcv valve??
 

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I don't have a Hemi, but I'm pretty sure that is the PCV valve. It is a funky thing that looks like some sort of Catch Can.

Go to Napaonline and look up PCV valve, there should be a picture. I think you twist to unlock and pull the actual valve out of the can, i.e. the "twist to lock".
 

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Discussion Starter #4
Yes, you guys are right. From searching for pics it does appear to be the PCV valve. Mine was pretty covered in oil on the outside and it looks like at one point it pooled around the base of the "can" looking part. Does that mean it needs to be replaced? I just looked at the owner's manual and it says to inspect at every 30k miles and replace if needed. I've never had to replace one but oil around the PCV valve is probably an indicator that it needs to be replaced, doesn't it?

I'm going to ask a newb question but what are the implications of a bad PCV valve? Is this something I can "feel" during driving. How else would one know other than visually inspecting it?

Thanks!
 

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How much oil are we talking about? If there is oil dripping from it and running down the engine and dripping on the ground, yea sounds like too much oil. If its just grimey in oil, that "may" be normal.

It may need to be just cleaned, sounds like your overdue.

The PCV valve often gets coated in oil, several cars I've owned from V-8's to I-4's the PCV and the tubes leading to/from it gets grimey in oil.

If the PCV valve was really malfunctioning it could make tapping noises, create a vacuum leak (which would have the symptoms of a vacuum leak) and allow oil past it to be ingested and burned by the engine (which would have the symptoms of engine burning oil). Of course those symptoms could indicate a serious and expensive problem with the motor, that can fixed by replacing the cheap PCV or even cheaper, just cleaning it.

The engine crankcase will have moisture from condesation, blowby, combustion byproducts, heat creating caustic fumes and other contaminants collect in it. Those contaminants will break down the oil, increased wear from poor lubrication, cause sludge and deposits.

Circulating fresh air through the crankcase and sucking out the moisture and fumes will have a huge positive effect on preserving the oil and the engine.

The "Positive Crankcase Ventilation (PCV)" valve is a flow control valve that uses vacuum from the intake manifold and meters it and stops back flow from surges the crankcase (pistons moving up and down create air pressure surges) backflowing into the intake manifold. So in normal operation it will suck in some oil from the crankcase and it will collect a bit by the PCV valve, it gets dirty, varnished, clogged with debri, etc it won't meter the air flow right and might start sucking up more oil than it should from the crankcase and/or allowing to much vacuum loss to the intake manifold.

Usually its just a spring loaded, weighted piston with a nozzle end that moves back forth with the air pressure to reduce/increase airflow and totally close the opposite direction to prevent backflow. So you can imagine how getting dirty can restrict the piston and cause it NOT to meter the airflow right. It might make the piston slam back and forth and create a tapping noise.

Some engine use an orifice instead of a piston.

Not sure on the Hemi PCV, never seen a PCV that big and I suspect looking at the parts it might be some sort of baffled/chambered orfice deal that also acts as a catch can for the oil. If that is true, then it is even more important to clean it periodically because oil would be collecting in it that has to be drained. If the oil isn't drained it would likely be forcing it way out of the can.
 

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Discussion Starter #6
Thanks, Mongo. That's some great information.

From the pictures you can see the area around it is grimy but what isn't visible is the oil that has pooled around the base of the can where the PCV valve sits. It's not much but it was enough to concern me.

From what you're saying it's probably a good idea to change it anyways. It seems like a simple replacement that can save some future headaches. That might also be the reason why I'm hearing a "tapping" noise right around that area during idle.

Thanks again for that info. I'm currently looking for the best place to order Mopar part # 53032940AB.
 

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From what you're saying it's probably a good idea to change it anyways. It seems like a simple replacement that can save some future headaches. That might also be the reason why I'm hearing a "tapping" noise right around that area during idle.

Thanks again for that info. I'm currently looking for the best place to order Mopar part # 53032940AB.
Again I do NOT own a Hemi, take this with a grain of salt, but what little I can tell it looks like it is designed to be taken apart and cleaned or just the critical part replaced.

If it was the typical $3-$10 throw away PCV valve, I would say, Sure, don't bother cleaning it and just replace it with new. But, I think the Hemi PCV valve is pretty expensive, and probably would work like new with just taking it apart, draining the collected oil, wiping it down with a rag and maybe spraying it all with brake cleaner, if there is an orifice cleaning it out with a pipe cleaner.

As well, something like a PCV valve? If it is offered by the aftermarket, I would just get an aftermarket one for less.

Of course the aftermarket can be iffy, I bought an aftermarket gas cap from a local autostore when I was getting a CEL for evaporative emmission control failure of the self-test. I wasted hours and hundreds of dollars on replacing other parts in the system trying to diagnose and fix it, finally when I got another brand new gas cap from the dealer the problem went away for good.
 

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Discussion Starter #8
That's true. Unfortunately I'm not too familiar with these in order for me to feel like I did a good job at cleaning it so at $35 it's not too bad to just go ahead and replace it with a new one. Regardless if it's being cleaned or replaced it seems like a good time to go ahead and do it.

Thanks again for the info.
 
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