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PCV line / Oil Catch can

56K views 102 replies 39 participants last post by  lithgow2790 
#1 ·
Could anyone confirm that this is the PCV recirc line in which to splice in an oil catch can? Look's like it's possibly the air pump from the crank case and going into the air intake line right before the turbo:




Would be a resource as I am sure many diesel owners want to get a oil catch.
 
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#41 ·
Ya, I checked out the "how do you tell if you have a real Provent" threads and mine was good to go. I think just maybe the multitude of connections I have there is a leak somewhere. Curious to know how the car senses a PCV problem, pressure?

I may re-design the hose setup and try and get better coupler's/reducers..
 
#42 · (Edited)
Curious to know how the car senses a PCV problem, pressure?
Pressure seems likely, because the line is putatively at higher pressure than ambient (other candidates such as temperature and O2 content wouldn't be altered via a pressurized hose leak). Pressure is going to be lower at the intake with the can installed, that's basic fluid dynamics. However, given the size/design of the ProVent, the pressure drop seems like it would be minimal.

If there is enough slack in your hoses, you could temporarily take the ProVent out of the PCV circuit (leaving it mounted in the compartment) and check the existing hose run by connecting it together without the ProVent to see if it still throws codes. If the problem persists, that suggests a hose problem. If it doesn't...
 
#46 ·
If it is indeed an overall pressure drop issue then it may be possible to compensate with larger lines (rough estimate of pressure drop is an inverse 4th power function of line radius). Reducing the number of size changing couplers would also help to decrease the pressure drop.

But then again, perhaps the example setup is fine and there was just a leak in a hose or coupling.
 
#47 ·
Zybane, just wondering about the latest on your catch can as I'm thinking about fitting one too.
Did you solve your error message problem?
Is it catching much oil?

Thanks in advance.
 
#48 ·
Well this is a real head-scratcher. I left the engine running and used spray-bubble soap on all the lines to check for any leaks. None. Then opened up the top of the Pro-Vent and clearly there was tons of fumes/exhaust coming from the PCV system. Put the top back on, disconnected the hose that leads into the intake with associated sensor. Visible exhaust coming out of that (less white as obviously going through filter. So mechanically, everything is working as advertised.

Not sure why I constantly get this PCV disconnected CEL. Does anyone know what exactly that sensor is measuring on the intake tube that the PCV exhaust goes through? There is a chap down in the export forum in Australia that has the Pro-Vent with his diesel and doesn't get a CEL. Then again, they have different emissions systems on their diesels. So strange this issue...
 
#49 ·
Not sure why I constantly get this PCV disconnected CEL.
Out of curiosity, did you ever try running the system with the same hoses but with the Provent removed? I'm planning to install a Provent this summer and based on your experience I'm already planning to use larger diameter hoses and as few couplers as possible in order to keep the pressure drop to a minimum.
 
#50 ·
Now I get the advantages of a catch can especially in our CRDs, but if adding one causes as many problems as Zybane is having it seems to be more trouble than it's worth. Is there a catch can that is more reliable than the Pro-Vent in the GC? I guess the Pro-Vent is the most effective, but I'd rather have something that works all the time and doesn't throw CELs. Or are those not effective enough to be worth the effort?
 
#51 ·
From Zybane:
Not sure why I constantly get this PCV disconnected CEL. Does anyone know what exactly that sensor is measuring on the intake tube that the PCV exhaust goes through? There is a chap down in the export forum in Australia that has the Pro-Vent with his diesel and doesn't get a CEL. Then again, they have different emissions systems on their diesels. So strange this issue...
In my opinion it would have to be restriction, causing an increase in pressure.
I suspect that with the tight turns and reducers, there is enough flow restriction to cause the messages. I would also suspect that you will need to replumb it somehow avoiding such tight turns and therefore avoid crankcase pressure buildup which would be causing the error messages.
Maybe the answer is having the catch can further away if necessary, with lower radius turns on the pipe and avoiding any reducers and/or 90 degree bends completely if possible.
Having said that, I'm sure a catch can is a very good idea. I will certainly be looking into fitting one, and the Provent seems the pick of the bunch. I regularly hear absolute horror stories on all makes about crud build up on turbos and inlet manifolds- a combination of oil residue and hot EGR gas cooking it all.

Good luck
David.
 
#52 ·
From Zybane:


In my opinion it would have to be restriction, causing an increase in pressure.
I suspect that with the tight turns and reducers, there is enough flow restriction to cause the messages. I would also suspect that you will need to replumb it somehow avoiding such tight turns and therefore avoid crankcase pressure buildup which would be causing the error messages.
Maybe the answer is having the catch can further away if necessary, with lower radius turns on the pipe and avoiding any reducers and/or 90 degree bends completely if possible.
I think this is probably the cause. I am running a Provent with no issues but I am using 1" inner diameter silicone tube throughout with no reducers etc. My Provent is also installed lower in the engine bay and sits under the a/c line which might help.
 
#54 ·
The error code "disconnected" might still be a red herring I think.
I fail to see how the (crankcase) pressure could be lower- it's just not possible to add extra plumbing and reduce resistance to flow.

Disconnecting the PCV line at the source (at the end of the camshaft) would indeed reduce pressure where it joins the intake, thereby no doubt causing such a message. I just can't imagine the error messages being caused by anything other than a restriction of flow.

My opinion anyway.
I'm very convinced that fitting a catch can is a very good idea- I will be doing so as soon as I have a chance.

(2,100 klms on the clock and we love our Jeep GC diesel):thumbsup:

Cheers
David
 
#55 · (Edited)
I just can't imagine the error messages being caused by anything other than a restriction of flow.
That's what I assumed as well. "Disconnected" meaning "I'm sensing a lower pressure than I expect". The catch can, the hosing, and the couplers all introduce additional resistance to flow that will inescapably reduce the pressure at the end of the run.

All we can hope to do is to minimize the pressure drop by minimizing the flow resistance. Since the can is basically unmodifiable, that leaves hosing (diameter and length) and couplers as variables.

I haven't decided how to attack this project, but my initial strategy is to run hoses that are the diameter of the catch can's ports (which I understand to be larger than the stock hosing) and place the size change couplers as the very first and very last elements in the system.

Not much space in the engine compartment, so this may be tough to accomplish.
 
#56 ·
One issue I am running into is I have yet to find anyone running a ProVent200 on a US spec diesel. All the ones are AUS, and their PCV system doesn't have this "Extra" sensor that US models have. Honestly I think that is whats causing my CEL, the US cars are more aggressive at monitoring the PCV system due to our crazy emissions laws.

Having a "disconnected" PCV would be a huge pollution law breaker under US code, so I think they set up the PCV system super sensitive to disturbance.

The CEL doesn't appear to affect the engine operation in any way, just want to get rid of that dang light plus the fault is being logged. So for warranty they could be like "why did you drive around for such a long time with this CEL".

I may have to re-do the entire hose setup. If it still gives an error, I guess I will have to go with a different/smaller catch can and sell the Provent.
 
#57 · (Edited)
I have just spent a little time this afternoon reviewing the catch can idea. I'm not so sure I would jump to the conclusion that the disconnected PCV code implies an open tube. Disconnected with the PCV plugged could easily be what they mean, we don't know for sure. Plugging it would be very bad for the engine as we probably all know. Increased crank case pressures would equal all sorts of problems. Either way, plugged or open to the environment, there are clear reasons for an error code I supposed.

The increased pressure thing triggering the fault code seems plausible to me. That is seems to occur during acceleration, when there would be increased crankcase pressure, may support this as well. It's also a common theme for the available catch cans to have too small inlet and outlet ports for what we need.

Anyway, just thought I'd throw that out there. I'm in agreement that there is a real need for one on this vehicle and am trying to figure out the best way to go, hopefully getting around the error code issues.
 
#58 ·
Ya, still playing around with it. The Provent 200 has huge 1" inlet and outlet's, should not be that restrictive (unless the paper element is). This may give the steel mesh type catch cans an edge as they should have very little pressure buildup vs a paper filter element. Although, the crankcase gases seem to be coming out the end of the tube that goes into the air intake track just fine.

I just bought a 1" elbow to plug in both sides of my tubing and eliminate the Provent and see if I still get the CEL.
 
#61 ·
Well, no CEL with the elbow installed. I will hook up the Provent and remove the filter and expect the same progress. Glad to know my lines are fine. I think that Provent filter is just too restrictive for US diesels PCV sensors. I may have to keep the filter removed and just stuff it will metal mesh. Won't be as efficient at capturing oil, but it's really my only option.
 
#63 ·
Yes, it's the filter element. The lines were never the issue. I replaced the filter with a stack of mesh copper sponges to collect the oil, no more CEL's. After about a 2,000 mile drive, I had about a half cup of oil collected.

I don't think the metal/mesh type catch cans (most types) are as efficient as a paper element, but that paper element is just too restrictive for US JGCD emissions systems. I'd rather have something catching some oil than nothing as before I even installed the catch can I could see/feel ton's of oil in the intake tract.
 
#64 ·
I don't think the metal/mesh type catch cans (most types) are as efficient as a paper element, but that paper element is just too restrictive for US JGCD emissions systems.
I don't imagine the engine "needs" the exhaust gas recycling, but rather that it's the EPA forcing the issue. Concordantly, I wonder if the sensor can be defeated, thereby allowing one to use the paper filter element in the ProVent despite the increased pressure drop it induces.

Anyone have an idea of how involved it might be to mock out the sensor with a dummy?
 
#66 · (Edited)
Wouldn't it be even healthier for the engine to hollow out the DPF and reflash the PCM to not require the DPF to be present/regen? I imagine that running the crankcase vent into the hollowed-out DPF might be a convenient option.

That's fairly major though, and the PCM would still need to be flashed or the PCV sensor replaced with a dummy in order to avoid throwing emissions codes for the disconnected PCV line.
 
#68 ·
i do not have a jeep yet, but have talked the wife out of a gl350 or a range rover sport supercharged, and into a summit thank goodness.

i have been trying to find exploded diagrams of the VM motor showing all of the parts to see how everything works. in my 2008 ram 6.7L, i have it running beautifully. i was getting 14mpg average stock, but now i am able to get about 16 city and 19.5 hwy @ 80mph (this is with 315 size tires too!).

as far as the CCV goes, all it will do is throw oil vapor into the turbo, coating the compressor wheel and everything else in the intake piping. once i get the vehicle, the first thing will be to vent to atmosphere.

i think there will be some great gains to be had from removing the DPF, but that will be for another day. mabe if i get super bored i will be able to find out what voltages that the O2 and temp sensors are looking for and get some sims made up so that they can all be fooled. really not looking to go down the tuner route as it should not be necessary with the right equipment.
 
#71 ·
i have been trying to find exploded diagrams of the VM motor showing all of the parts to see how everything works. in my 2008 ram 6.7L, i have it running beautifully.
Milous was kind enough to post the Chrysler VM 3.0 student guide in a thread. You need to be a premium member to get to it.
 
#75 ·
Still having no codes with the SS mesh? I have noticed that with my catch can and SS mesh installed I only get the P04DB code thrown when I'm getting close to a regen. It works great up until around 60% soot percentage on my DPF. I am going to try and remove some of the mesh I have installed to see if that corrects the code. It is strange that it works 90% of the time though without issue.
 
#77 ·
http://www.burgertuning.com/BMW_335_oil_catch_can.html

Installed this about a week ago and am have no CEL's, no pending codes and it seems to be catching oil much better than the SS Mesh/standard catch can. No modification to the hoses, necessary! Works out of the box. A little pricey, but seems to be well worth it. A member of the RAM1500 forum put me on to this and he has put thousands of miles on so far with no codes!
 
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