Oil Consumption and Dirty Intake

[cham]

I've had my 02 LE for around 4 years now and I love it to death which is why I'm willing to spend the money to aid in longevity even though it'll soon rack up 170k miles.  Now I recently solved an issue with the fan clutch which I had been suspect about for years but funny enough everyone I talked to claimed it was synonymous of these pathfinders.  Eventually, I pulled the trigger on a hunch and voila the loud semi-truck roar was gone and returned was some low-end torque and slightly better mpg at least it seems that way so far.  This was a great step in the right direction but it has opened up now all the peculiar and interesting sounds coming from the engine which I had not been hearing before.  Now I have also been burning oil ever since I can remember which is nothing surprising but never understood its potential effects and how destructive it can be.  I decided to take a look at the throttle body the other day and it just about scared the @!*% out of me how bad it was compared to what I've seen online from people showing how to clean them.  My valve cover gaskets for sure need to be replaced as I can see cooked oil just outside of them but what this all means is the PCV system is letting loads of crud feedback into the intake and I'm a little nervous to take a look inside the plenum.  I plan to get the notorious valve cover gasket replacement done this summer but due to the high cost, I wanted to make a list of everything needed to avoid ever having to undergo this process again.  So I'll start out with what I already know should be done and if anyone has any recommendations, or advice I would be more than willing to listen.

 

Forgive me if I sound ignorant as I don't know enough about this procedure.  The gaskets other than the valve covers, are there a lot that need to be ordered and should I only use oem factory parts?  I feel like I've read somewhere that Nissan released altered/improved gaskets for maybe the valve cover or some related gaskets in this area to help improve the stock ones in our R50s.  Can't confirm how valid this is.  It sounds like as well that there is a left and right side valve cover gasket and to me it looks like both need to be replaced because I can see cooked oil on both sides.  Now something I've recently been looking into is an oil catch can which sounds like a savior for anything intake related and better for the cats as well.  Can anyone point me in the right direction for a high-quality one which will last the life of the car?  I also wanted to bring up if there is ever a possibility of adding this altering the pressure of the system in some way and throwing off a sensor or affecting the performance of the engine?  I just want to make sure I cover all of my basis, excuse me if I'm sounding a little anal.  Also because of all this crud and grime being thrown back into the engine, what do I need to look into cleaning when disassembling everything down to the valve covers.  Would this include the upper and lower plenum?  For sure the throttle body but I might as well wait until I do this job as it could just build up again in between now and I when I get around to doing this.  I've heard the actual valves themselves can be pretty bad if an engine exerts a lot of blowby but I'm sure I can't really get to them even if I go down to the valve covers?  That's unknown to me maybe someone can clarify.  Thank the lord it's not a GDI haha.  Maybe I can use some sort of solvent while I've got everything apart?  Anyways finally I wanted to address the screws that everyone warns about backing out due to vibrations and causing a ruckus.  I don't know if it's just me but it seems like either there are multiple things that need to be loctited to avoid this or there is simply different names for the same set of screws.  I've heard butterfly screws, power valve screws, and maybe it's just the valve cover screws that everyone is talking about.  Maybe all of these need to be loctited.  Regardless I've said enough this one is a long one but if I plan on keeping this truck for any significant period of time this needs to be done and hopefully only once.  Let me know of any suggestions and maybe how coils/injectors/spark plugs lie in all of this mess.  

[02_Pathy]

Mine's an 02 LE as well and it does consume oil even before the leaks I have now which I'm slowly fixing. It's just the nature of the VQ35 in other Nissan's as well even though some don't consume that much. When I took my manifold off to do the coolant crossover pipe gaskets and loctite the power valve screws, my upper plenum was coated with oil. Also when I replaced my PCV valve I didn't really see much improvement on oil consumption, it still consumed the same amount although depending on my driving style it varies. I would recommend getting all the gaskets for the upper and lower plenum as well as throttle body gasket as it is easier to have those items off when you do valve cover gaskets. Also be aware that Nissan made the spark plug gasket o rings non serviceable on the valve cover. So if you pull it off and put a new gasket on the valve cover the spark plug o rings might not seal again on the spark plug holes which could get oil down in them. That is the only reason why I haven't done my valve cover gaskets. I've heard you can rip them out and put new o rings in but I would be concerned if you accidentally gouge them and they wouldn't seal. As far as gaskets I just used the gasket set that Mahle makes and got it off rockauto.    

[jjonez]

To add to 02_pathy, the spark plugs and seals in addition to the potentially clogged baffles in the valve covers are the reason why when I eventually do this job I plan on replacing the covers completely.  Not sure what part # gets you the updated design, and not sure if it does any good either.  They are expensive, I think around $200 each last I checked.

[RainGoat]

By Notorious Valve Cover, I assume you mean the Power Valves-here are some notes:

 

POWER VALVES

http://www.nissanpathfinders.net/forum/topic/17104-threadlocker-on-power-valve-screws-pics/page-1

 

Power Valve (Butterfly Valve) Screws on Intake Plenum

They are power/swirl valves...the swirl valve actuator is what opens and closes them

6 butterfly valves in the upper manifold held in with 2 screws each

tiny phillips screws, size and thread pattern is m3x.50 10mm length

Remove each screw & Loctite red threadlocker=permanent

2-3hrs, just a lot of bits and pieces to take off/put back on

 

page EM-10 for torque specs for all of the removed hardware, and EM-12 for the upper intake manifold bolts.

 

Intake Manifold torque-all 12mm bolts and nuts at 20lbs.

 

Gaskets (4) ordered from dealer

16175-4w000 (throttle body)

14033-4w000 (right side, between upper and lower intake plenum also called 14010A*)

14033-4w010 (left side, between upper and lower intake plenum also called 14010AA*)

14033-4w00A replaces 14032-4 (between lower intake plenum and intake manifold also called 14040E*)

* (part numbers as shown on exploded view in the print-out given to me by dealership, dunno why they don't match the p/n on the packages... all gaskets fit perfect.)

 

Power Valve Butterfly Valve Screws

Altima Part#14511-8J00B

they come with washers on them which are kind of a pain to remove but need to come off. 

Three Bond 1375B, Nissan Part#14511-8J01B.

 

 

 

[cham]

Trying to filter through everything as best as I can so I don't miss something significant.  I appreciate the in-depth info here's to hoping I can comprehend most of it.  What it seems like to me from just my own personal experience and research is a huge factor to the oil consumption is excess blowby past the piston seals which once in the crankcase is sucked through the pcv valve consisting of not just exhaust gases.  Once rerouted through the intake, siphoned oil begins to either coat whatever it comes in contact with before reaching the combustion chamber or is then burnt off within the combustion chamber which then contributes to a clogged cat, a lot to go wrong here.  I've found that the excess blowby is attributed to obviously the fact that we've got older cars and seals wear out but on the other hand have read about the cylinder walls themselves being discovered to have more taper than they should which would explain premature wear and oil consumption.  This could be due to poor quality control who knows but it makes sense considering some R50s just never had a problem with oil burning and some did, check that a lot did.  I'm sure this might not be anything new to you all but thought I'd share anyway just my 2 cents.  I'm open to anyone finding flaw with my theory, there's definitely a lot of people on this forum who know more about the VQ35DE than I do.

I digress, from what it sounds like though I'm going to need new spark plugs as well which isn't a huge deal mine are on probably 30-40k.  Speaking of spark plugs I've seen a lot of debate and is there a clear superior plug over the others or pretty much just get what was originally factory installed?  Now in reference to the valve cover itself, is it pretty easy to determine if the baffles are clogged when you have it in front of you?  The hard part is knowing to order it ahead of time or not because I'd hate to have the engine apart in that kind of state while waiting for it to be shipped.

On 2/4/2019 at 1:01 AM, RainGoat said:

Power Valve (Butterfly Valve) Screws on Intake Plenum
They are power/swirl valves...the swirl valve actuator is what opens and closes them
6 butterfly valves in the upper manifold held in with 2 screws each
tiny phillips screws

 

On 2/4/2019 at 1:01 AM, RainGoat said:

Power Valve Butterfly Valve Screws
8 in Number
Altima Part#14511-8J00B
they come with washers on them which are kind of a pain to remove but need to come off. 
Three Bond 1375B, Nissan Part#14511-8J01B

Lastly the only thing I'm really confused about is what you said RainGoat about the Power Valve/Butterfly Valve screws being what needs to be removed and loctited if hopefully they are still there.  You said there are 6 butterfly valves with 2 screws each which equates to 12 screws.  At the bottom of the post, you mentioned there being 8 in number.  Is this something totally different or are you giving me a reference for getting extras in case yeah some have backed out and are missing and the set happens to only come with 8 screws?

[RainGoat]

Oops. That was a quick cut & paste of my notes. 12 screws. Hopefully they’re all there & you just reuse them. Mine, unfortunately, ultimately had to come from my JDM engine replacement : (

Use the linked thread for good info.

[cham]

Thanks RainGoat this has helped loads now just the funds for this behemoth. 

[Sjackson2]

Replace the gaskets, do the iacv gasket while you’re at it. Bypass the coolant lines to prevent drying the iacv and ecu as well. New plugs. New plug seals if you have aluminum valve covers, new pcv balve(you’ll probably need to do the pcv hose and the breather hose also as they get very brittle) and maybe do a catch can while you’re at it. Other than that it’s a relatively straight forward job if you label everything so you can put it back together