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Trainman

Power Valve Screws Falling Out On 3.5's, 01-04

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I had the job done yesterday and it took them 2.5 hours. No screws were missing or loose but better be safe than worried!

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Can somebody post a link of a technical manual showing those screws with the torque that they need. I have an appointment next week to get it done but the guy looked like he didn't new what I was talking about and got me a bit scared... :wacko:

 

No torque they're just tiny brass phillips screws that need to be tight.

 

and 88 HOLY CRAP whos engine was that?? bet that thing made some noise eh?

 

sorry i havent checked back in here for a while, having also done this myself if I can be any help let me know :)

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Ok guys, those of you with the hands on knowledge...lets get us all straight here!!

 

 

---------Inset knowledge here-----------

 

 

--> You will need # ___, ___, ___, ___, gaskets for a good clean re-installation of these 2 manifolds (and TB)

 

-->There are 2 manifolds to the intake.

 

-->Remove pretty V6 3500 cover and all electric connectors

 

-->???? # of bolts and other accessories on top of manifold #1

 

--> after removing manifold #1 ( ___ bolts) you will see ???

 

--> Moving forward, remove the lower manifold to ? (get to the manifold butterflies?)

 

--> ??They can fall into the motor at this point of removal??

 

--> Use ________ type of loctite to re-install phillips brass screws

 

 

-----Myself included (as I am still shopping for my rig), should then be able to do this on our own with ___ mechanical knowledge.

 

This topic is a very important topic of any VQ35 owner whether Path or QX4 or Max, Alty, 350z, even the little Spec V Sentra, I hope that nobody sees this as a pushy post asking for a step by step. I do not want to make any mistakes and I have had enough with shoddy dealer/shop work. I am buying a Pathy instead of the Q because I am determined to lift mine and put HUBs on it sooooo I want to perform this surgury on my own...preferably with in 1 week of purchase (or length of time to get gaskets!!).

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Ok guys, those of you with the hands on knowledge...lets get us all straight here!!

---------Inset knowledge here-----------

--> You will need #Lower im gasket (metal and rubber) 2 gaskets that mate the upper and lower I.M. and throttle body gasket for a good clean re-installation of these 2 manifolds (and TB)

 

-->There are 2 manifolds to the intake. Yes upper and lower halves

 

-->Remove pretty V6 3500 cover and all electric connectors Yes also the small metal brackets on the TB side of the upper manifild

 

-->???? # of bolts and other accessories on top of manifold #1 I dont have a count right now but its few and simple

 

--> after removing manifold #1 ( ___ bolts) you will see ??? the upper bolts are all visible from the top and vary in length so make sure you lay them out in order, also there are 4 nuts on studs at the corners believe it or not the hanes was most helpful here with the torque order of all these, once the upper half is off you will see the butterfly valves on the driver side and a line of open holes on the pass side, under light throttle the air passes through the long tube route and when you floor it or reach a certain rpm those valves open for a larger and more direct air route. at this point you can do what needs done but use caution because if you lose one it can go into the motor. (heres where you gasp in horror ;) )

 

--> Moving forward, remove the lower manifold to ? (get to the manifold butterflies?) You dont have to remove the lower IM but if your sketchy about losing the screws inside then it is easier to work with out side of the truck, this is the only time you will need the lower im metal/rubber gasket is if you go all the way. Also if you do take the lower part off you need to get two small bolts out of the rear passenger side of the lower im that hold a small metal bracket to the back it seems that its only there for stability and to hold one hose up, and they are a real bitch, if you have a gear wrench for these two you will be much happier than i was with only a box wrench hehehe

 

--> ??They can fall into the motor at this point of removal?? if you only remove the upper part yes its possible

 

--> Use ________ type of loctite to re-install phillips brass screws I got some of the green thick loctite from the dealership, the guy was cool and squirted some in a parts baggy i had with me or else its VERY expensive to buy a tube, and you really need so little.

 

-----Myself included (as I am still shopping for my rig), should then be able to do this on our own with ___ mechanical knowledge. I would say very little, you just need to be patient and be sure you keep the bolts in order, thats my opinion though so it might help to have a friend there to reference the book and keep track of bolts while you work or something.

 

This topic is a very important topic of any VQ35 owner whether Path or QX4 or Max, Alty, 350z, even the little Spec V Sentra, I hope that nobody sees this as a pushy post asking for a step by step. I do not want to make any mistakes and I have had enough with shoddy dealer/shop work. I am buying a Pathy instead of the Q because I am determined to lift mine and put HUBs on it sooooo I want to perform this surgury on my own...preferably with in 1 week of purchase (or length of time to get gaskets!!).

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I know you probably wanted pictures and part numbers here but I dont have that right now, I do hope this helps out and if anyone can add to this please do, and if someone else wants to try to clean this up for a proper how too, please feel free :) i'll try to be here for any questions too.

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------------>Dude! That is an awesome write up!!<--------------

 

This is exactly the type of information needed! I picture, as often as possible, when I first joined the site and what confused me....the pins that we have now are awesome! To make these pins detailed as possible is a must. The only thing that I think could be improved is to have a "PIN" that gives the raw info, and then sort of a sub column that gives all the room to talk about it, that way people that are zooming in for the info can get that with out deeply serching the multiple pages of posts.

 

Again Jarsiff, that is a BIG help! I now feel like I am capable of doing the repair/check!

Edited by 98silverpathy

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thanks :) glad I could help :aok:

Edited by Jarsiff

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Just returned from the local dealer...got all my gaskets ordered....the Plenum spacer in no-way, shape, or form will fit our trucks :suicide:

 

The only hope (without complete customization) for more ponies is the throttle body coolant-bypass spacer. I will update!

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Ok, as mentioned before, Haynes was a big help, perfectionists but helpful!

 

-->Remove all intake ducting and box (makes life easier, and then install pop charger)

 

-->Take off pretty cover (2 nuts 1 bolt)

 

-->Take photo of all vaccuum lines running around TB then disconnect them

 

-->Use socket style hex head to remove throttle body, caution gasket may want to fall towards ground when removing throttle body from intake

my dealer gave me the wrong gasket for the TB so I needed to preserve its shape---when ordering gaskets they will need manufact. month and year

 

-->Set TB aside and start on 13 assorted fasteners that hold top IM onto lower IM, "crack" them loose first the remove in torq order per Haynes

 

-->Use cardboard to hold bolts/fasteners in order to re-install correctly

 

-->On passenger rear there is a bracket that does hold the upper IM to the lower IM and simply holds O2 wires or something

(2 brackets, just remove the rear-most bracket)

 

-->Pry--GENTLY--the upper from the lower, there are all sorts of reasons that they will get snagged not wanting to separate up and out of the engine bay

(small hoses and brackets that will rub against making contact etc--small working area)

 

-->Look immediately at left side of air tubes for your throttle screws

 

-->Go do an End-Zone dance---or---curse Nissan

 

-->Carefully remove each screw (#2 phillips-un damaged to ensure your screws do not strip) apply loc-tite (medium for me) and reinstall with good evenly applied pressure

(I found that out of 12 screws 4 were easily removed, the rest were quite snug---I also found these to be magnetic--thus not brass---the throttle plates are under heavy

spring load, so it should be difficult to dump a screw into the motor while working)

 

-->Clean TB with teflon approved cleaner, intake with regular style of degreaser

 

-->Re-install upper IM with fasteners in order of Haynes WITH rear passenger bracket first-----(I must admit I am not totally convinced you need to use new gaskets as these

are rubber coated metal gaskets, however I did due to my personal issue with Murphy's Law)

 

-->Re-install TB, at this point you could bypass the TB coolant line also if you feel confident and have a 3/8 vaccuum "T" and clamps (I think it was 3/8)

 

-->Pretty cover, intake, bla bla bla let Loc-Tite cure and happy trails with your now cured VQ!!!

Edited by 98silverpathy

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Ok, as mentioned before, Haynes was a big help, perfectionists but helpful!

 

-->Remove all intake ducting and box (makes life easier, and then install pop charger)

 

-->Take off pretty cover (2 nuts 1 bolt)

 

-->Take photo of all vaccuum lines running around TB then disconnect them

 

-->Use socket style hex head to remove throttle body, caution gasket may want to fall towards ground when removing throttle body from intake

my dealer gave me the wrong gasket for the TB so I needed to preserve its shape---when ordering gaskets they will need manufact. month and year

 

-->Set TB aside and start on 13 assorted fasteners that hold top IM onto lower IM, "crack" them loose first the remove in torq order per Haynes

 

-->Use cardboard to hold bolts/fasteners in order to re-install correctly

 

-->On passenger rear there is a bracket that does hold the upper IM to the lower IM and simply holds O2 wires or something

(2 brackets, just remove the rear-most bracket)

 

-->Pry--GENTLY--the upper from the lower, there are all sorts of reasons that they will get snagged not wanting to separate up and out of the engine bay

(small hoses and brackets that will rub against making contact etc--small working area)

 

-->Look immediately at left side of air tubes for your throttle screws

 

-->Go do an End-Zone dance---or---curse Nissan

 

-->Carefully remove each screw (#2 phillips-un damaged to ensure your screws do not strip) apply loc-tite (medium for me) and reinstall with good evenly applied pressure

(I found that out of 12 screws 4 were easily removed, the rest were quite snug---I also found these to be magnetic--thus not brass---the throttle plates are under heavy

spring load, so it should be difficult to dump a screw into the motor while working)

 

-->Clean TB with teflon approved cleaner, intake with regular style of degreaser

 

-->Re-install upper IM with fasteners in order of Haynes WITH rear passenger bracket first-----(I must admit I am not totally convinced you need to use new gaskets as these

are rubber coated metal gaskets, however I did due to my personal issue with Murphy's Law)

 

-->Re-install TB, at this point you could bypass the TB coolant line also if you feel confident and have a 3/8 vaccuum "T" and clamps (I think it was 3/8)

 

-->Pretty cover, intake, bla bla bla let Loc-Tite cure and happy trails with your now cured VQ!!!

Will somone please tell me how to upload my pics!!! They are under 100KB and the upload function will not work! --->And I don't know how to load more than one on a post anyhow.

 

The upload feature seems very size limited, like under 100kb total for all the pics you've ever hosted here or something. What i do is go to one of the free image/photo hosting sights, upload the pic to them. then i come here, start a post or reply to one. the photo hosting site gives you a URL to your pic. You copy that URL, then paste it in the post your working on here, and voala, you've got a pic in your post. It automatically turns the code (url) the pictures site gave you into a picture here. Hope that helps, i suck at the right lingo... It's simple copy and paste from the hosting sight you choose, no upload on this site.

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The upload feature is not working anymore. For some reason it quit on us. Sorry. I keep forgetting to call IPB for help on that.

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GREAT write-up...I have a feeling as time goes by and more and more VQ owners start googling "butterfly screws" or something along those lines, we're going to see more and more hits on this great info.

 

Thanks man :aok:

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Something I just thought of...

 

What happens if, upon opening the thing up and looking inside, you find screws missing? Are you immediately SOL? Though I'm anxious to do mine, I'm terrified to open the thing up and find this. Though the truck runs just fine, doesn't exhibit any oddities and doesn't burn oil, I guess you never know till you do it...

 

But what to do if you find this?

Edited by navygz19

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theres really nothing you can do about it, if its not displaying any ill behavior your probably fine, looking back when i first complained about that super loud clacking noise that went away in a couple miles, thats what it had to have been is that one missing screw "passing" if you find that you have one or more missing and are still biting your fingers about it then do a compression test on your motor and that will either alert you to a problem or give you back your piece of mind :) my motor passed one screw and it runs GREAT, others may not be as lucky as i was.

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Yeah I remember when you posted about that noise you were getting. That's about what I thought...

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Do a compression test to check for damaged rings, valves or pistons first. If the test turns out OK, I wouldn't really worry about it. If one is off by more than 10-20 lbs, I'd start worrying. :(

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Ok, as mentioned before, Haynes was a big help, perfectionists but helpful!

 

-->Remove all intake ducting and box (makes life easier, and then install pop charger)

 

-->Take off pretty cover (2 nuts 1 bolt)

 

-->Take photo of all vaccuum lines running around TB then disconnect them

 

-->Use socket style hex head to remove throttle body, caution gasket may want to fall towards ground when removing throttle body from intake

my dealer gave me the wrong gasket for the TB so I needed to preserve its shape---when ordering gaskets they will need manufact. month and year

 

-->Set TB aside and start on 13 assorted fasteners that hold top IM onto lower IM, "crack" them loose first the remove in torq order per Haynes

 

-->Use cardboard to hold bolts/fasteners in order to re-install correctly

 

-->On passenger rear there is a bracket that does hold the upper IM to the lower IM and simply holds O2 wires or something

(2 brackets, just remove the rear-most bracket)

 

-->Pry--GENTLY--the upper from the lower, there are all sorts of reasons that they will get snagged not wanting to separate up and out of the engine bay

(small hoses and brackets that will rub against making contact etc--small working area)

 

-->Look immediately at left side of air tubes for your throttle screws

 

-->Go do an End-Zone dance---or---curse Nissan

 

-->Carefully remove each screw (#2 phillips-un damaged to ensure your screws do not strip) apply loc-tite (medium for me) and reinstall with good evenly applied pressure

(I found that out of 12 screws 4 were easily removed, the rest were quite snug---I also found these to be magnetic--thus not brass---the throttle plates are under heavy

spring load, so it should be difficult to dump a screw into the motor while working)

 

-->Clean TB with teflon approved cleaner, intake with regular style of degreaser

 

-->Re-install upper IM with fasteners in order of Haynes WITH rear passenger bracket first-----(I must admit I am not totally convinced you need to use new gaskets as these

are rubber coated metal gaskets, however I did due to my personal issue with Murphy's Law)

 

-->Re-install TB, at this point you could bypass the TB coolant line also if you feel confident and have a 3/8 vaccuum "T" and clamps (I think it was 3/8)

 

-->Pretty cover, intake, bla bla bla let Loc-Tite cure and happy trails with your now cured VQ!!!

 

 

Chris I just PM'ed you about the TB removal...nevermind, I forgot your write-up explains it all!!

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Hello Gentlemen

 

I have just bought a late 2004 Pathfinder. It was first registered in early 2005 and has 15K on the clock and a full MD service history. It seems pretty good so far.

 

Can anybody advise me as to whether I need to worry about the throttle body screws coming loose? Did Nissan do anything about the issue on later models or are all years at risk?

 

I also read somewhere about exhaust manifold studs and cracking of the manifold. Same question to the learned.

 

Many thanks in advance.

 

Regards

 

Richard

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I do believe that the manifold stud issue was with older models, but you definitely have potential to have the power valve issue, with so few miles on it I would be torn between getting in there and making sure its taken care of before anything happens and waiting a while until i need to replace something else while im in there, your not going to need plugs for quite a while and while you should be able to re-use your gaskets, ive never been comfortable with that. If your careful you will only need to take off the top of the upper manifold and you can do the job in the truck...

hope that helps.

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Thanks Guys.

 

Is it fairly straightforward for an average mechanically minded guy like me to do the powervalve screws? Any special tools required? Anybody done a pictoral walkthrough post?

 

I'm an OK home mechanic as long as the engine stays in the car. I can change a cam belt, valves, oil seals etc.

 

Regards

 

Richard

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On a side issue, I have been told by several Nissan dealers (Kamloops, Kelowna and Victoria) that the 3.5 is also subject to exhaust manifold issues, notably cracking, warping and broken studs. May explain the ticking I have right now :(

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Also getting some ticking from the drivers side. I re-used the gaskets when putting the new engine in. I have not bothered to look and determine where exactly the sound is coming from. Also, I have an annoying vibration sound at and around 2000rpm. I think it's probably a manifold heat shield coming loose, since I broke one of the 10mm bolts during extraction. I'll let you know what I find, if or when I do..

 

For the rest of you waiting on my power valve status on the wrecked engine and my current one. It might be a while yet. The old engine is in the back of a poorly lit barn, out of town and I have been busy with work and other stuff. Will also post what I find with pics if I get that done.

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