Vented oil catch can - heads up!

[L36]

If you have a vented oil catch can on your M and you live in the north I suggest you check your oil cap. If you're getting slight mayo on the oil cap which is a indicator that you have a bad head gasket, this is not the case. Your oil catch can has lots of water in it. Make sure you empty your OCC on weekly bases. For the past few days i was losing my mind thinking my HG was bad. Luckily its not the case.
This pretty much applies to anyone who has a vented OCC, not just Ms.

[svard75]

Thanks for the headsup. Although why or how would the oil catch can get water inside? condensation? The oil catch can sit between the valve cover and the intake plenum. In a normal PCV operation the valve would allow for the gasses and oil to pass along into the intake plenum to be burned off through combustion. The oil catch can now catches the oil and it sits at the bottom correct? So if condensation were to build up inside the catch can it should remain in the catch can not travel either way. Do you have a proper catchcan and not just a can with two connections?

[L36]

I still have my PCV valve in place. The reason why water gets in is because its vented into the environment and the condensation easily gets inside the can. In addition with this cold and humid weather we have had for the past weeks in the north east, it creates perfect conditions for lots of condensation to form in the can. I don't get oil into my can, since its direct vent and is not hooked up to the intake, it simply connects to the valve covers. One connection from PCV and another from the other side that goes into intake tubing.

Then block off the intake tubing and the plenum from the PCV. Oil consumption now is non existent.

[svard75]

Sorry I edited my last post after reading a bit more on catch cans. I think the problem here is you have no vaccuum for the PCV to operate. There has to be vaccuum correct?

LOL we're writing posts too quickly. I just saw your last post. So you do have one side connected to your intake?

[L36]

You can have vaccum, but that would suck oil from the valve covers. I have no vaccum at all.

[svard75]

Read this article http://oilcatchcan.com/ I think the lack of vaccuum that you introduced can be causing excessive engine pressure. Read the part just before the first animated picture.

[L36]

The lack of vaccum will not cause engine damage. Positive pressure will. Since the drivers side valve cover has no PCV valve its a direct vent into the air intake tube. On the other side I have the PCV valve which does block the pathway but the valve covers have a hose connecting the banks together so the gases in both banks can equalise with each other. Thus all gasses go to the driver valve cover where they head out the venther catch can and are vented into the atmosphere.
This leads to no crankcase pressure at all time. Therefore I don't see his the lack of pressure can damage the engine.

[svard75]

Ah I see. So the additional vents exist or did you modify your valve cover?

[L36]

No modification as of yet but I'm thinking of pulling the PCV valve and putting a fitting in its place to give it additional ventilation.

[svard75]

It makes sense to me that the natual compression stroke would be sufficient positive vaccuum to push the gasses out through the valve covers so not sure why that guy said in his article that you needed the negative vaccuum from the intake to make the engine as reliable as possible. I used to plug in the K&N breathers in another life and the engine was fine.

Anyway which catch can did you get?

[L36]

I got the jegs one, though i just took the OCC off and put the stock setup for the winter. The amount of goo in there is just huge and this winter is letting too much moisture into my engine and due to temp difference causing a lot of it to condensate in there. I never had this issue in my G35 coupe during the summer with identical setup. Guess for winter time ill run stock set up. I fear that all this moisture might due more harm than good for the engine.

Now that guy does have a valid point though that some engines out there require the PVC system to make a proper ring seal and if its vented it can cause ring damage. Many BMW have this kind of setup. Though I'm not aware of this to be the case for VQ35DE/HR

These are the parts i used from jegs
Part # Description Unit Price Qty Price
555-52202 BRETHR TANK -10 CLR SHORT $84.99 1 $84.99
555-110003 #10 STR HOSE END BLACK $9.99 2 $19.98
799-670710 -10AN X-10AN PORT ADAPTER $11.99 1 $11.99

Then i bought some 5/8th hose - 6 feet from ebay and a foot of 3/8 hose. Bought a brass 5/8 to 5/8 fitting and 3 5/8 hsoe clamps and and set it up in a similar manner as in this video. http://youtu.be/JebJf2o0NRw

[svard75]

Thanks for the details.

[L36]

Ive decided it would be a good idea to post an update to this. Sometime in February of 2015 Ive removed the vented catch can. Primary reason being is that it introduced an insane amount of moisture to the engine. While oil is designed to deal with moisture, the amount of moisture a vented catch can was introducing was just too much. This was deep during winter months and probably would not be the case during summer or for anyone who lives in the south.

The point I'm making is, if you live in the north do not get a vented catch can. Personally, I would not even get a vented catch can at this point no matter where I live. Stick with a closed system based catch can.

[cruzad3r]

so i never have any catch can in any of my car and i love to tinker with car. so my question is, we all know the VQ35DE engine sucks a** with oil consumption therefore does a catch can help with this issue?

[L36]

so i never have any catch can in any of my car and i love to tinker with car. so my question is, we all know the VQ35DE engine sucks a** with oil consumption therefore does a catch can help with this issue?

Catch can will not solve your oil consumption issue. What it will do is keep the lower portion of your intake plenum clean of oil. There is a section of the lower plenum in the center where all of the oil sucked through the PCV sits. The engine sucks up this oil and burns it.

This burning of PCV oil can have several negative effects such as detonation and sludging of the upper cylinders / compression rings. Thus the point of the OCC is to collect this oil and allowing you to safely dispose of it instead of the engine burning it and in the process causing detonation and sludging.

[cruzad3r]

ok - thanks.