So, today I replaced my PCV valve. It took 7 hours. Here's why:

I obtained the four gaskets for the upper and lower intake manifolds, the PCV valve itself, and the grommet that goes around the PCV valve a few days ago. Today, a friend and I started work on it at about 1 PM. It was raining, so we moved some crap around in his garage and I pulled the front end of the PF in. This gave us very little room to work in. So anyway, I remove the plastic engine cover and start work on the passenger side, by removing the two brackets that hold up some wiring harnesses. That took all of 2 minutes. I then began removing the various hardware atop the upper intake manifold - accelerator bracket, etc. I'm short, so I had to climb in and crouch atop the top radiator support to gain access to some bolts... this becomes a recurring theme.

With that stuff off, it's time to remove the air intake tube and throttle body. To further complicate things, there's a bunch of immovable stuff up pretty much everywhere in the garage, so to access the driver's side, I had to go through a labyrinth involving walking over and around stuff constantly. My tools were also on this side, so this got tiring quickly. The air intake tube and throttle body came off easy, as does the upper intake manifold. Bolts/nuts get labelled with masking tape and a sharpie.

Now the real problems start. As some of you know, the lower intake manifold collector has a support bracket on the passenger side corner, right up against the firewall. It's impossible to get tools back here pretty much. The uppermost bolt came out pretty easy; the other, not so much. For some reason, both were already pretty loose (a blessing or a curse?). It took 30 minutes fiddling with a box wrench, sockets, etc to loosen the bolt enough to spin it out by hand. Why is this thing back here?! The top 2 bolts and 2 nuts on the manifold are then removed.

So at this point, I'm drenched with sweat since it's over 9000 degrees out. It stopped raining, so it's ridiculously humid. Sweat doesn't help. We lift the lower intake manifold off, and what do we find? A PCV valve snapped in half. I forgot to move the PCV hose aside, and the undue stress caused it to snap.

It took probably 30 minutes with some pliers to actually pull the remaining half of the valve that was still inside the valve cover, since a good majority of it fell in the damn valve cover. After carefully applying pliers to remove the largest chunks, I, uh... felt around with my index finger to retrieve any remaining significant chunks of residue. Not fun, let me tell you. At least I didn't need to pull a valve cover.

So, now that that's over, we wrestle with the new PCV valve and grommet for 10 minutes trying to fit it in... the grommet and valve are a very tight squeeze. We eventually get it in, I slap the new gasket on, and we take a well deserved break.

We spend an hour trying to reposition the lower intake manifold back on the engine, which was a troublesome task due to the cramped engine bay, cramped working area, and the extremely stiff PCV hose that needed to go on before the manifold could be set in place. We call a buddy over and he helps us, and we finally maneuver the thing back on and I start buttoning things up - ensuring to use the proper torque spec and tightening order, mind you. The damn support bracket bolts were not torqued with a wrench; the easier-to-access one was tightened with a box wrench, and the other one was just as snug as I could get with my fingers.

I complete reassembling the manifolds. I loosely install the throttle body, then realize I still don't have the proper hex bit to torque it to spec. I removed it using an 8mm Allen key, but my 154-piece Craftsman toolset doesn't have an 8mm hex bit. Oh well, tightened using the Allen key in the proper tightening order, hope it'll be fine.

More annoyance strikes during reinstalling the intake tube. The stiff vacuum hose on the firewall side gives us trouble, but by this point we already had installed and tightened the damn tube (d'oh). We remove it, and wrestle with it some more... we're done, right? I check over hoses, etc and start it up. We hear a high pitched noise, and I shut it off. The damn air intake tube wasn't flush at all with the airbox housing (hey, it's dark, and we're sweaty and tired by now). We remove the thing again and put it on properly this time, and all is well.

But wait, there's more! I ended up with an extra part: one spacer. No idea where it came from. It was resting on top of the rearmost wiring harness support bracket on the passenger side (the one with the stud for the engine cover), but it obviously shouldn't have been there since the nut for the engine cover couldn't be screwed on with it there...

Whoever buried the PCV valve under the intake manifolds should be shot. I sure as hell hope I don't need to do this again any time soon. And I thought putting threadlocker on the power valves was tough... hah. They all look fine, by the way.

I think this is the wordiest post I've typed up here so far...

That sounds terrible.

Anyway, was there a need for replacing the valve or was this just preventitive maintenance?

Sounds like you had yourself a fun time

I dont know why this was so complicated for you even with the heat, i remember i did mine with my dad about a year ago in my garage and it was hot as hell out too, it didn't take us anywhere near that time, probably like 3 hours working slowly, and then having to run out to find a pcv valve from a 03 maxima or 350z, cause the one my dealer sold me wasnt threaded, but i ended up finding one cause i also broke mine and then needed one to put it back together.

Anyways look at it this way, the jobs done.

I was replacing CV boots on my audi a4, and they use this stupid concept of "pinch bolts" it took me about 4 hours each side and taking breaks, to pound out one stupid bolt on each side, thats using air hammer, hammer, big sledge hammer, etc.

This was just preventative maintenance. The valve was in use for 128,041 miles, and obviously I had no idea how to tell if it was working.

I guess every car has its own "impossible to access" part somewhere... in this case, it's the PCV valve.

Towncivilian wrote:So at this point, I'm drenched with sweat since it's over 9000 degrees out. It stopped raining, so it's ridiculously humid.

I feel your pain. I've got a pretty long to-do list of car stuff, but nothing's getting done until we get better weather.

Great reading, a thrill a second and the outcome was un-suspecting! Get that gun ready for the PVC installer.

During the making of these vehicles the engine is a completed assembly and all hoses, clips, wires are plugged in via plug type affairs.

The manufacturer could care less when things last at least to warranty end because as you have discovered outside warranty is billed work and more time = more money.

Congratulations on a job done!

Here is the parts list for replacing the PCV valve for a 2001 or 2001.5 Pathfinder:

• 16175-4W000 GASKET-THR (throttle body gasket)
• 14033-4W000 GASKET-MAN (first of two upper intake manifold gaskets)
• 14033-4W010 GASKET-MAN (second of two upper intake manifold gaskets)
• 14032-4W00A GASKET-ADA (gasket between upper and lower intake manifolds)
• 11810-31U00 VALVE ASSY (nonthreaded PCV valve)
• 11812-41B00 INSULATOR- (grommet that goes around PCV valve)

All of these parts are required. I paid $69.82 after tax at my local dealership (I get net/wholesale prices).

For 2002-2004 R50s, I believe the PCV valve is threaded, so it will have a different part number. I do not know if the grommet/insulator is required since it's a threaded PCV.

And the parts for a 2003 Pathfinder:

• [16175-AR000] GASKET-INTAKE MANIFOLD
• [14033-4W000] GASKET-MANIFOLD, UPPER
• [14033-4W010] GASKET-MANIFOLD, UPPER
• [14032-4W000] GASKET-ADAPTER
• [11810-8J102] POSITIVE CRANKCASE VENTILATION VALVE

I'd imagine this parts list is correct for 2002 and 2004 models as well, but send me your VIN for confirmation before purchasing so I can look them up.

I posted these in this thread since the general information thread links to the previous reply with the parts list.

aw dude, now i appreciate how the pcv valve is super accessible on the 3.3, not to rub it in or anything :P

Heh yeah, I don't know who thought burying the PCV valve under the intake was a good idea.

If Nissan dealer doesn't have this is there any reason not to use a Auto-parts store like Autozone ?
I intend to do the Power valve screws soon, and if its that or leave the original ?

Aftermarket PCV valves may be specified for many different engines, each with different opening settings. I would not chance an aftermarket PCV valve, even if it were easily accessible. Definitely use an OEM PCV valve with our VQ35DE engine. Order online if you must. If you want confirmed OEM part numbers, provide your VIN.

Ok Thanks I will get one in advance ready to go. delay wont be bad.

What else while its apart, I know about plugs, waited till they are due to do the Power valves. Has anybody had loose swirl valve screws ?

You shouldn't need to replace anything else besides the various gaskets of course (throttle body, 2x upper intake manifold gaskets, 1x lower intake manifold gasket). I would suggest adding a PCV catch can as it's easier to do so while everything is apart. It helps keep the throttle body and intake manifolds cleaner since you're catching those nasty blow-by gases and vapors instead of having them deposited into the intake. The catch can will require periodic emptying, but this should not be an issue. You can see an example setup in this post.

I have not read of any instance of swirl valve screws coming loose. Just apply red threadlocker to all of the power valve screws and sleep easy at night.

Great Idea for catch can, I assume this is just a Oil water separator for a compressor from Lowes ?
Cant see a part number.
I recommended putting one on a high Oil consumption Pathy on another forum but didnt have any idea where to get one. Also didnt know the PCV was buried so deep.

Yes, that's exactly what can be used. I'm unsure of a part number as well, sorry. I think your best bet would be to go to your local Lowe's and look around for a suitably large enough.

Also what about the Valve cover baffles, is this a rare issue !!!

I'm unsure about that. I think if one keeps up with oil changes, it should not be an issue. I have 140k miles on my Pathfinder without a drop of oil consumption. If I were suffering from excessive oil consumption, I might consider pulling the covers to check the baffles.

I brought mine at 25K and 15 months old, Oil consumption is up and down a bit, and averages a quart or 3 pints per 5000 miles when newer, and less now, I would say 1 - 1.5 pts per 5000 miles.

It used to noticeably use more when on trips on highway when i am pushing it along at 75 + mph. Dont notice this as much these days, and speed limits here are now higher, 80 and 85 Mph limits in places. I hope this accounts for my lower trip MPG !!!