tmoore4512 Posted February 24, 2012 Share Posted February 24, 2012 (edited) Okay guys, so I am in the process of doing a valve cover gasket job on my Pathfinder VG30E... When I pulled the intake plenum off of the lower intake, I observed a large buildup of oily chunks on the intake walls... Not entirely sure what is causing this, and how to correct it...I do not want to put the top end back together without addressing this... It appears that from the passenger side valve cover the tube that connects to the intake is blowing junk up into it... Had to stop because it is down right cold... Any insight by you motor building guru's is most appreciated... This is the lower intake And the nasty valves... And the inside of the valve cover from that side... Edited February 25, 2012 by tmoore4512 Link to comment Share on other sites More sharing options...
Towncivilian Posted February 25, 2012 Share Posted February 25, 2012 If you install a PCV catch can, it will condense the oil vapors that come out of the PCV valve and eliminate a lot of oily build up in the intake manifold. But the build up in your pic looks pretty nasty, not sure what to make of that. Link to comment Share on other sites More sharing options...
5523Pathfinder Posted February 25, 2012 Share Posted February 25, 2012 (edited) Yep, just carbon buildup from the PCV system. VG's are well known for it. If it builds up, it can create a lack of power and worse, and misfire condition. Easy to clean up though. Carb clean will clean a large part of it up. I perform a Induction Service with a chemical(BG) and cleans that crap up. You can accomplish similar results by spraying in intake cleaner from any parts house(make sure its sensor safe, and you use it in a well ventilated area), from just behind the air flow meter(small vacuum hose). I did this not long ago and had a thread about it. I will see if I can find it... Here ya go.... http://www.nissanpathfinders.net/forum/index.php?showtopic=31832&st=0&p=600196entry600196 I took pics threw the throttle body, but same as what you have. Edited February 25, 2012 by 5523Pathfinder Link to comment Share on other sites More sharing options...
tmoore4512 Posted February 25, 2012 Author Share Posted February 25, 2012 Thanks for the input. I run a can of Seafoam every time I do an oil change (via vacuum lines) and expected it to be cleaner... Time to find out if the PCV is clogged... probably... Catch can? Link to comment Share on other sites More sharing options...
Tungsten Posted February 25, 2012 Share Posted February 25, 2012 x2 on the BG intake system That was the absolute first thing I had done when I got my truck. I was hesitant to try it but did it anyway. The idle dropped from 1000 rpm to 750 rpm and all the power struggling issues just went away. Definitely some carbon build up there after 140k miles (mileage at that time, now I have over 250k). Link to comment Share on other sites More sharing options...
5523Pathfinder Posted February 25, 2012 Share Posted February 25, 2012 The buildup in the valve cover and rockers is just oil that has broken down(sludge). Most of the time this is no big deal. Its really only a problem whne it builds up excessively. I have worked on a old hardbody that was not taken car of and the sludge was built up all around the rockers! Needles to say, it needed a rebuild. What you have is no big deal. If you clean any off, be sure none drops down the oiling passages as it could block up the oil pickup in the pan. ON the valve cover, you can clean it with any parts cleaner, or if you have a machine shop near, you can give it a solvent bath(hot tank). Link to comment Share on other sites More sharing options...
Towncivilian Posted February 25, 2012 Share Posted February 25, 2012 A catch can is a device that is installed in-line on the hose leading from the PCV hose to the intake manifold. The blow-by vapors slow down and condense in the container and eventually must be dumped when the catch can becomes full, which is the only downside to a PCV catch can set up (constant maintenance). Some people use an in-line air tool filter. NICOclub has a DIY guide for installing a catch can on a Maxima, but the basic concept is the same for almost every vehicle with PCV. See the guide here. Link to comment Share on other sites More sharing options...
tmoore4512 Posted February 25, 2012 Author Share Posted February 25, 2012 Interesting... In theory, if the PCV is working correctly this shouldn't occur... I am assuming that there is some serious blow by causing all the garbage to be blown up from the valve cover into the intake... The write up is very informative... Thanks Town! Link to comment Share on other sites More sharing options...
Tungsten Posted February 25, 2012 Share Posted February 25, 2012 So that is just a water catcher for a compressor routed between the PCV output and intake? Link to comment Share on other sites More sharing options...
Towncivilian Posted February 25, 2012 Share Posted February 25, 2012 So that is just a water catcher for a compressor routed between the PCV output and intake? Yeah, that's the cheap way of doing it. I'm not sure whether it'll stand the test of time, it might be worth it to get something beefier and built purposely to act as a PCV catch can. Link to comment Share on other sites More sharing options...
tmoore4512 Posted February 26, 2012 Author Share Posted February 26, 2012 This is something similar to what I am looking at putting into use on my old wore out Pathfinder.... http://www.ebay.com/itm/BLUE-UNIVERSAL-JDM-750ML-ROUND-BILLET-ALUMINUM-OIL-RESERVOIR-CATCH-TANK-CAN-/180780633648?pt=Motors_Car_Truck_Parts_Accessories&vxp=mtr&hash=item2a175d8e30 Link to comment Share on other sites More sharing options...
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