Hi all:

I have take the engine apart on my pathy to add the loctite to the power valve screws to avoid them getting sucked into the engine.

A HUGE thank-you to my buddy Steve - without his experience from working on his Maxima and his help, I'd likely still have my finger stuck in a swirl valve....
A BIG - thank-you to all who posted about this issue to alert those of us not in the know....

Note to Mods: I /IMG tagged my pics from photobucket. If someone wants to upload and modify my post for posterity, cool. Can't guarantee my photobucket account forever of course...

Details
'02 Pathy LE
111,000km (~69,000 miles)

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.)

These cost me approx $72 CAN as the Nissan dealer cut me some slack on the tax. The last gasket is the most expensive, almost $50. If you were going to leave the lower intake plenum on the engine to do this job, you would not need this gasket. I personally think it worth while to remove the lower plenum, makes life easier, only 4 screws hold it on, no dropped screws inside the engine.. up to you though. Some people think that these gaskets can be re-used and you do not need new ones at all - probably true, but with my luck, I decided not to do it twice for $70 and got new ones.

The following is my rough account of how I did the job, not every step is in here, but should give an overview. If you are a real noob to auto mechanics, this may be more involved than you want to try. Much harder than an oil change. Not nearly as hard as changing a transmission or even a clutch though. If an oil change is a 1 out of 10, and an engine rebuild is a 10 out of 10, this job is a 4 in my opinion.

Quick Notes:
Left and Right - refer to the side of the vehicle, so when I say left, I mean from the driver's perspective - just to be clear.
I did not cut any factory tie straps!! They unclip from underneath if you squeeze the tabs together and then you can pop them back in later.

Disconnect battery negative cable!!! viannen_09.gif This protects electronics.

Remove plastic engine cover (2 nuts and a screw). Look in awe at all the bloody wires and hoses. unsure.gif

Remove the *mounting bracket* for the accelerator cable and what I guess is the cable from the cruise to that go to the throttle body. I did not remove the the lock nuts at the cable end, just the mounting bracket (2 screws). Unclip the the cables from the plastic clips at the front of the engine. There should now be enough slack in the cable to move them toward the throttle body - the cable ends slide to the side out of the half round throttle body mounting points. Then flip the cable assy upside down and backward toward the battery - DO NOT kink these! nono.gif

Remove the brake vacuum line from the rear centre of the upper intake plenum.

Remove the hose leading away from the evap valve on the upper intake plenum near the throttle body.

Then remove the air intake hose. There is one mounting screw on the resonator box down low (in the following pic, the mounting point is visible just below and to the side of the master cylinder) to remove, plus 2 band clamps and a couple of hoses.

This thing will be hard to get out, you will need to remove the hose from the throttle body end first and the twist and contort it out - watch the plastic box underneath doesn't get hung up stuff (it will). I did not remove the airbox. This would make life easier I bet, but I felt I could get by without the extra step.

Then remove the hoses around the power valve vacuum actuator at the front left of the upper intake plenum.

There are two brackets on the right side, rear of the upper intake, that are bolted to the lower intake (one has the mounting screw for the plastic cover). That one should be loosened and pulled back. They both need to come loose, so might as well do em both now.

Unclip the two tie straps for the evap control valve @ back of throttle body. Disconnect two connectors at throttle body (throttle position switch and idle air control valve, brown is on top, but I think there is only one way to reconnect). I did not disconnect the coolant lines to the throttle body. I removed the 4 mounting bolts (hex key on a socket extension works best).

and used some wire tied it off out of the way to the dip stick.

Using the reverse of the torque tightening sequence from your manual, remove the 13 fasteners from the upper intake plenum, and them remove it. Carefull, it could get hung up on stuff. Put the bolts in a card a number them

as they are different lengths and need to go back in the same spot!

There are only 4 fasteners holding the lower intake in place - or so it would seem! sssh.gif There is secretly a hidden bracket on the right side back, between the firewall and the lower plenum. The right most bolt will require a short 12mm wrench to get at it. This was the hardest fastener to deal with. Then the the 4 main fastners can be removed in reverse tightening sequence order.

Will continue in a reply post.....



Post Title: Re: Threadlocker on Power Valve screws (KoukiS14)
Posted by: KoukiS14 at 5:51 AM 1/7/2008

The hose system underneath at the back disconnected earlier (shown now to help understand where to disconnect in the earlier step).

Ok, so now everything is apart. I clean the power valve area with some carb cleaner and blow it off with compressed air.

Then I remove ONE screw (to make life easy for lining up things up for assembly) and drop it in some carb cleaner and liberally blow some carb cleaner in the threads of teh mounting shaft.

Looking at the screw, it has some gunk in the threads. I need an easy way to remove the crud from these fine threads, so I got a small wire brush from a dremel rotary tool set and put it in my drill, in the vice. The screws have a round head and holding just the head with pliers is likely to launch them across the room, so put pliers on them top and bottom of the screw, seemed to work well enough.

I then blow out the threaded hole with compressed air, and ad a drop of loc-tite 242 (blue removalbe for 1/4" and larger, not so easy to remove on smaller screws, may require heat!) and reassemble. Repeat 11 more times.

Use compressed air to blow any crud out of the plenum runners.

Clean all the gasket mounting surfaces with a clean rag and carb cleaner or similar.

Installation is reverse of assembly....

BUT........



Post Title: Re: Threadlocker on Power Valve screws (KoukiS14)
Posted by: KoukiS14 at 5:56 AM 1/7/2008

I had done the power valves, but the valves underneath those are the swirl valves. ugh.

I did not have the gaskets to remove the manifold and there was no way you could or would want to do the screws with it on the engine. Plus you'd have to mess with fuel lines. So, I did something that may have no effect at all, but thought it was worth a shot:

I got an old toothbrush and sprayed it with carb cleaner liberally. My buddy Steve held the valves open with a soft handle of a hammer

and I brushed the back side of the screws with carb cleaner and dried them with compressed air. I then put some blue loctite on the tip of a small clean flat blade screw driver and carefully dabbed it on the backside of the screws.

Maybe that will all wash off, likley. but it is better than nothing in my mind.

Oh - one other thing, changing plugs is easy when you are this far apart, I recommend it!
Just remove the coil, one bolt, and then you have access to the plug.

It is waaaay down inside the valve cover.

The book calls for a .043" gap. My factory plugs measured .044 after ~69k miles, so I gapped the new ones to .042 and stuck 'em in - they should be good for another 69k I hope.

Changing the plugs can be done another time, but you will be moving most of the same hoses and brackets and you will have to remove the throttle body to get to one of them, I think it is #4.

Hope y'all found this thread useful. smile.gif
Ron



Post Title: Re: Threadlocker on Power Valve screws (KoukiS14)
Posted by: KoukiS14 at 7:38 AM 1/7/2008

Good call. . I'll get ahold of him. .



Post Title: Re: Threadlocker on Power Valve screws (KoukiS14)
Posted by: timmack at 8:07 PM 3/12/2008

Post Title: Re: Threadlocker on Power Valve screws (KoukiS14)
Posted by: c_law23 at 8:59 PM 4/12/2008

Thanks



Post Title: Re: Threadlocker on Power Valve screws (c_law23)
Posted by: KoukiS14 at 6:53 AM 4/25/2008

Well sheeeeeeeeeeeit. . .



Post Title: Re: Threadlocker on Power Valve screws (KoukiS14)
Posted by: car-parts-happy at 10:36 AM 5/19/2008

EDIT!
Just re-freshed! Oops. I'll take a good look at the guide later - could be useful with my latest project




Post Title: Re: Threadlocker on Power Valve screws (car-parts-happy)
Posted by: KoukiS14 at 4:04 PM 5/19/2008

Hope it works out for ya, otherwise I stole it from that dude for no reason. . haha



Post Title: Re: Threadlocker on Power Valve screws (KoukiS14)
Posted by: pathfinder9035 at 12:08 PM 12/1/2008

No need to contact me for permission to use the photos, I found you first!

Just kidding... I am happy to have the pics here - I want everyone to be aware of this issue and avoid problems, same way I benefit from others' How To posts. So keep this post here! Small caution, I am not promising to keep my photobucket account forever, so if you want to d/l a rehost those photos here, you have my blessing. I do appreciate the credit for the initial write-up. Anyone wishing to add/update/correct info along the way has my blessing too.

Side note, from what I have gathered this does NOT apply to 5 speed manual rigs. From what others at NPORA have posted the manual trans equipped rigs do not have thses valves at all.

Hope that helps!

Ron



Post Title: Re: Threadlocker on Power Valve screws (Bow_Tied)
Posted by: sobiloff at 1:05 PM 3/20/2009

Then I found this thread.

So, I asked the dealer to check the power valves and they just called with the verdict: one screw gone and the loose valve was binding the entire assembly, restricting airflow into the engine.

While I'm happy that I've finally tracked down the problem, I'm frustrated that this has happened to my engine. I've asked the dealer to see if they can get some consideration from Nissan/Infiniti since this clearly is a quality failure and not the result of wear or abuse. I know I'm out of the warranty by both time and mileage (69K miles on the truck now), but I hope that they'll help offset the cost a little. (I haven't gotten the final bill, but I'm probably looking at $600 for the work.)



Post Title: Re: Threadlocker on Power Valve screws (sobiloff)
Posted by: montrose michael at 10:59 AM 4/8/2009

Your notes and comments and pics by friend KoukiS14 confirm my problem and the solution by my mechanic. IT AMAZES ME THAT THIS PROBLEM IS HAPPENING. Seems an engineering issue that is a design flaw. I'm not expecting help from Nissan at 98k miles but this surely isn't the reliability I was expecting from Nissan.
MM



Post Title: Re: Threadlocker on Power Valve screws (montrose michael)
Posted by: montrose michael at 3:10 PM 4/8/2009

Thanks for asking.



Post Title: Re: Threadlocker on Power Valve screws (montrose michael)
Posted by: jeffcrider at 7:27 AM 9/1/2009

I'm in a pickle and need some help.
Just last week a screw fell out of my power valve and into the cylinder of my 04 pathfinder. (76,000 miles)

The dealership quoted me $3500 to take the screw out... but they couldn't guarantee that the engine wasn't scratched and ruined, so if they got the screw out and found the engine was scratched they would then need to replace the engine for an additional $8,000 to $12,000...

I'm thinking I get it towed back to my house and I try my best to take the heads off and take out the screw myself and trade it in when I'm done

Any thoughts on this?
Is there a DIY somewhere for this?

I've already tried to get Nissan to cover it but I was denied

Not sure if this is needed info or not.
But they tell me it is in the #4 cylinder (2nd one back on the passanger side looking at if from the front of the vehicle)

-Jeff


Modified by jeffcrider at 10:47 AM 9/1/2009



Post Title: Re: Threadlocker on Power Valve screws (jeffcrider)
Posted by: montrose michael at 11:52 AM 9/1/2009

That seems to be the deal, plus or minus. The thread on this topic is sadly interesting and very informative. If you think you want to tackle the job yourself, scroll way to the top and you'll be able to read and see pics of a part by part repair posted, courtesy of a talented do-it-yourselfer. he gives and excellent discription and some dos and don'ts.

Good luck.



Post Title: Re: Threadlocker on Power Valve screws (montrose michael)
Posted by: jeffcrider at 9:58 AM 9/2/2009

BUT!!! I'm actually set (I think) I was able to borrow a borescope and look at it my self. it appears as the screw is smashed and imbedded into the piston head. The knocking sound was the screw hitting the top of the head. and now the screw has been (hopefully) permanently imbedded into the piston. there is no knocking anymore!

(I'm going to trade it in ASAP)



Post Title: Re: Threadlocker on Power Valve screws (jeffcrider)
Posted by: jeffcrider at 12:10 PM 9/4/2009

I have one question though. Is it possible to take the upper intake plenum off the top of the engine with out removing the throttle body?
It looks as though i could just un screw the intake plenum and lift it up and fix the power valve screws but not actually take the intake plenum out of my vehicle.

Reason i ask is because i want to get this done asap (today or tomorrow) but no one has the throttle body gasket... i'd have to wait till middle of next week to get the gasket.

What do you think?



Post Title: Re: Threadlocker on Power Valve screws (jeffcrider)
Posted by: jeffcrider at 7:17 AM 9/5/2009

And i was mistaken on exactly where the power valves were. I thought they were on the upper plenum. they are actually on the lower. I removed the upper and was able to remove the screws and put thread locker on them and replaced them while the intake was still attached to the engine. I had no clue what i was doing and it only took about an hour to an hour and a half. it really wasn't that hard.

Thanks for the DIY!

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