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-   -   Is this the PCV valve? (http://www.jeepgarage.org/f5/is-this-the-pcv-valve-19677.html)

nick.jeff 03-02-2011 02:20 PM

Is this the PCV valve?
 
1 Attachment(s)
With the light shining on it?

2005JGC 03-02-2011 02:24 PM

Re: Is this the PCV valve?
 
yep

nick.jeff 03-02-2011 02:38 PM

Thanks! Just twist counter-CW to get it off?... I tried a minute ago and it wouldn't even budge.

LTrainGC 03-02-2011 02:51 PM

Re: Is this the PCV valve?
 
Yeah - it's a bitch to get off.

nick.jeff 03-02-2011 05:23 PM

2 Attachment(s)
Got it off with some pliers. The old one was covered in oil...see pictures. Is this normal? Is this occurrence something that could be solved with a catch can? I guess I don't really know what the PCV does and only vaguely understand the purpose of a catch can.

I went ahead and put the new one in for now but am wondering if I should get a catch can first and then put the new one back in, unless this is normal.

SvenskaJeepGuy 03-02-2011 05:28 PM

Re: Is this the PCV valve?
 
as long as the oil isnt going through it to the other side you are fine.

jeepgcoman 03-02-2011 05:54 PM

Re: Is this the PCV valve?
 
Nick-jeff, by the looks of that valve, it hasn't been changed in a long time, if ever. What year is the Hemi, and how many miles on it? Also looks like you're in a cold, damp climate. If the valve is that bad, you need to check the backside of the throttle body butterfly and the intake plenum for puddling. If large amounts of this crap gets into the engine and combustion process, you get lots of carbon buildup on the valves and piston tops, especially if you're running dino. oil. The catch can goes in series with the line from the PCV Valve and the intake manifold. It catches most of that junk and keeps everything in the intake system a lot cleaner. Here's a quote from a post by a Diablosport tech. (Mike) on the effects of this and the need for the catch can:

"No, this is where I comment on lost power due to oil contamination in the intake tract/combustion chamber. I will assure you that after having seen as many logs of as many HEMIs as we have here at DiabloSport, not to mention the numerous HEMI vehicles we have had on our dyno for R&D, I can say, without a doubt, that the HEMI's PCV/Oil Vapor control is the worst of anything we deal with. All you have to do is pull your intake manifold to see the puddles of oil collected in there, and realize that it eventually gets in the combustion chamber, and oil don't like to burn, thus, detonation occurs.

There is no gimmick here. HEMI's have KR issues. The KR issues are 99% of the time contributed to by oil contamination in the intake charge, reducing the effective octane in the combustion chamber, and leading to a loss of performance.

Plenty of people have seen solid power gains on even stock vehicles when getting rid of an oil issue by adding a catch can that works properly.

Thanks"

Hope this answers some of your questions.

Walt 03-02-2011 08:02 PM

Re: Is this the PCV valve?
 
Quote:

Originally Posted by nick.jeff (Post 367848)
Got it off with some pliers. The old one was covered in oil...see pictures. Is this normal? Is this occurrence something that could be solved with a catch can? I guess I don't really know what the PCV does and only vaguely understand the purpose of a catch can.

I went ahead and put the new one in for now but am wondering if I should get a catch can first and then put the new one back in, unless this is normal.

1. Definitely get an oil catch can. However, realize that this point is before the oil catch can. It will still get cruddy (bad news); clean it every 20-25K miles and it won't look like that again (good news).

2. PCV valve can be checked: Should rattle when you shake it. Biggest issue is likely that the o-rings are not intact and need renewal.

3. For the future, twist 1/4 turn CCW, then pry GENTLY upward to help it out. Lubricate o-rings with clean lube oil or teflon lubricant before re-installing.

The function of the PCV valve is to route crankcase vapors containing unburned hydrocarbons (gasoline vapor, lube oil vapor, and evaporatred moisture) into the intake manifold. These used to be vented directly to atmosphere and were named as a causative factor in smog formation. The PCV system uses manifold vacuum to suck the vapor out. Makeup air is introduced by the little hose from your air cleaner tube to a point on the LHS of the engine forward of the oil filler neck. Oil Catch Can just condenses these nasty vapors and collects them before they are able to get into your intake manifold and create an oily carbon crud. [If you didn't like it on your PCV valve , you won't like it inside your intake manifold.]

In my case, it coated the piezoelectric diaphragn on the MAP sensor with that stuff.

nick.jeff 03-02-2011 08:04 PM

Thanks jeepcogman & Walt, very useful info. It's an '05 Hemi, 74,000 miles on it. I've owned it since 54K and I would imagine the PCV has never been changed. Gibson exhaust, Fram intake, diablo predator for performance mods.

I just switched over to royal purple synthetic 4000 miles ago and will be changing here in 1000 or so. I'm in central Illinois, so pretty cold/snowy winters and rainy springs.

I also got a new EGR with the PCV valve so I'll look at the butterfly/intake when I put that on. For the PCV, I think my best option is to check it in a week or two and if oil is still showing up in that amount I'll probably go for a catch can. Is it possible to clean the PCV valve?

jeepgcoman 03-02-2011 09:44 PM

Re: Is this the PCV valve?
 
You can clean it, but if it's passing a lot of crud, just replace it. It's a dealer item (at least I haven't found and aftermarket one) and runs ~$25. While you're doing the contamination inspection, you might do as Walt suggested and pull the MAP Sensor and use an inspection light to look up inside. If it's contaminated, replace it too. It's available at dealer and aftermarket and also runs ~$25. I changed all that stuff at my 60K inspection/maintenance. Will be doing the 02 Sensors on Saturday, as they're becoming lazy.

blackpepper 03-02-2011 11:14 PM

Re: Is this the PCV valve?
 
I follow jeepgcoman and walt's posts religiously.. heed their advice.

dmsfun 03-03-2011 03:06 PM

Re: Is this the PCV valve?
 
Quote:

Originally Posted by nick.jeff (Post 367944)
Thanks jeepcogman & Walt, very useful info. It's an '05 Hemi, 74,000 miles on it. I've owned it since 54K and I would imagine the PCV has never been changed. Gibson exhaust, Fram intake, diablo predator for performance mods.

I just switched over to royal purple synthetic 4000 miles ago and will be changing here in 1000 or so. I'm in central Illinois, so pretty cold/snowy winters and rainy springs.

I also got a new EGR with the PCV valve so I'll look at the butterfly/intake when I put that on. For the PCV, I think my best option is to check it in a week or two and if oil is still showing up in that amount I'll probably go for
a catch can. Is it possible to clean the PCV valve?


Gonna have to change mine here too, and get a catch can. Just my .02 the Hemi does not like Royal Purple. I ran it for 2 oil changes and switched to Valvoline synpower; Valvoline is much better, as the MDS kickng on and off with RP is notably rougher. It appears RP 5W20 is actually much higher viscosity than they spec.


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