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

[powervalve]

Pathfinder power valve failure

 

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I have a 2004 Pathfinder that had the power valve screws in the intake back out and fall in the cylinders and fry the engine. I have 33,000 miles on the car, but I am past the warranty period by six months. Nissan refuses to replace the engine under warranty. This is the same problem that the Altima's and Sentra's have seen which is recorded on TSB NTB05-058. I am writing letters to both Nissan North America and NISSAN Motor co. I have also contacted Newsday and will be sending them all the info. If anyone else has had this problem, please contact me at un33dit@yahoo.com so I can have more info to fight with.

 

Thanks,

[88pathoffroad]

Here's another link to the above poster's thread:

 

http://www.nissanforums.com/pathfinder/140...ve-failure.html

[02silverpathy]

What is really bad here is that even offering a recall to "tighten" the screws would be admitting a mechanical failure...thus initiating paying for new engines to those that have gone through this. It sounds crappy cause it is, this is just how corporate worlds exist. They step over people to get what they need...the good side is that they will most likely never have that problem again. Japanese engineers are very good about fixing mistakes and thinking steps out and around the topic to predict what could be next. I would like to see Nissan replace all the damaged VQ35de's with VQ35HR's to make up for the issue!! Lol, I already tightened mine, ah well, that HR seems really sweet!

 

Trainman...where did you read of a manifold problem for VQ's?

Edited December 3, 2007 by 02silverpathy

[Trainman]

Trainman...where did you read of a manifold problem for VQ's?

 

Did not read, was told by a dealer that it was a common problem. But in my case it is a lifter that is making the noise.

[irich]

Pathfinder People.

 

My situation is this: I can do the mechanical stuff myself for the PV screw thing no problem. But I'm stuck out in the desert in the Middle East and I have no Haynes manual for the bolting sequences/torque settings etc.

 

If anybody can PDF or JPG me a good legible copy of the relevant pages of the Haynes manual for the Upper manifold removal I'll do a full photo walk through with associated text and all relevant technical info for the Forum.

 

I also don't have any gaskets out here, so Im going to reuse the originals. The engine has only done approximately 17K so I'll see how this works out.

 

If anybody can help.

 

Regards

 

Rich

[Phantom01Pathfinder]

I recently just bought a 2001 LE Pathfinder with 80k. I called the dealer today after reading all these forums on the power valve screws coming loose and getting sucked into the intake. The service manager said there hasnt been any recall about this problem on Pathfinders, but he did say hes seen it happen on some altima's and sentra's. well i told him about all the websites ive gone to and read all this stuff about people having motor failure do to screws coming loose. i asked him how much it would cost to check the screw problem and loctite all of them, and he said $200. that seems like a small price to pay to have a peace of mind, plus a mechanic with 30yrs experience will be working on it.

 

i am so veery pleased that i have found all these forums to assist me with problems. hopefully everything will go well.

 

thanks

[Phantom01Pathfinder]

So i just got back from the Dealership, and so far so good. i went in at 1030 this morning and the mechanic started to tear it down. He told me that the screws were not to the point of falling out, but they came out easier then they should have...so $200 later and some lock-tite, im good to go. oh also had the MAF replaced, got a deal worked out with the mechanic, so no more SES light.

 

NOTE: ANYBODY WITH AN '01 TO '04 PATHFINDER, GET THIS PROBLEM CHECKED OUT!! YOUR BUTTERFLY SCREWS MAY NOT BE TO THE POINT OF FALLING OUT, BUT THEY COULD BE VERY LOOSE!!!!! it'll be worth an extra couple hundred dollars to keep you pfinder running!!!!

[88pathoffroad]

I find it ridiculous that you should have to pay for the service in the first place. Nissan is denying the problem exists and it's not right at all.

[navygz19]

They pulled the SAME crap with me when I had my 2002 SE-R...the EXACT SAME ISSUE! Difference being, I choked the original engine in that car when the screw fell into the cylinder and smashed #4 cylinder spark plug. THEN they replaced the engine, with 1K miles left on the powertrain warranty.

 

What the fcuk is it with power valves and the screws holding the valves in place anyways? I've about had it with shoddy Nissan craftsmanship, of late anyways.

 

Should have never gotten rid of my 97 D21 4x4 with the (slow) bulletproof Z24.

[BowTied]

Hi all, new guy here. First this is a great forum for info, really glad I found it!!!!

 

So I am pretty worried about this issue for my '02 LE. I have been reading here and on other forums and have a couple of questions:

 

Are the screws brass or not? Someone says they are, someone else says they are magnetic?

 

Am I correct in thinking that "power valve" and "swirl valve" are different names for the same thing here??

 

What type of thread locker are you all using? Loc-tite 242? Are you using the removable or the permanent threadlocker?

 

If anybody can PDF or JPG me a good legible copy of the relevant pages of the Haynes manual for the Upper manifold removal I'll do a full photo walk through with associated text and all relevant technical info for the Forum.

 

Wow!!! great offer Rich - I really hope someone with a Haynes can help. I will see if I have anything to send, but not sure if it will help.

 

Ron

[02silverpathy]

I found them to be magnetic on my magnetic screw driver...they are zinc plated or something that makes them look like brass. I used the MEDIUM threadlocker, as it should be plenty strong and it prevents them from shaking loose, which is apprently the problem. They are power/swirl valves...the swirl valve actuator is what opens and closes them. At this point I would say that you can definately re-use the gaskets, as I have had my mannies off 2x and used the one set over with no ill affects. I would say to spend the money on a new PCV valve from the deal (so it fits right). This piece is what made my intake look amber in color!! It is under the bottom manifold on the left valve cover (when you are facing the engine) and it is facing toward the middle of "V" at the back.

[navygz19]

Man I still need to so this. Chris, you wanna take a trip to the Va. beach oceanfront and give me a hand? I got your gas if you do LOL!

 

Ahh yes, the PCV valve. This brings up another great point..that it too should be changed. Oil consumption in VQ's is caused by two things...power valve screws falling into the cylinder bank and scoring the walls or a clogged PCV valve, which can be easily changed while the valve cover is off for the P.V. job. Not enough emphasis is being put on this other job because it's easily overlooked, but equally important.

 

If only it weren't the holidays and I had some time on my hands...

[BowTied]

Thanks for the extra info guys, I appreciate. I'd give you a hand if I lived closer, Ontario is a bit of a drive from Va. Beach!

[BowTied]

My dealer got me the gaskets a lot faster than expected. I want to attempt the repair tomorrow. My local parts place says the Haynes doesn't make a manual for the pathfinder

If anyone can scan the useful pages and send them to me, I'd appreicate it!!

 

my email is ss396nospam@sympatico.ca (remove the 'no spam' from my address). Thanks!

Ron

Edited April 17, 2008 by BowTied

[navygz19]

My local parts place says the Haynes doesn't make a manual for the pathfinder

 

 

Parts shops guys are idiots. Was it an Advance/Auto Zone? They probably didn't see one for the Pathfinder because the Manual is combined with 98-04 Pickups and 00-04 Xterra's, as well as 96-04 Pathy's, The part # for the Haynes Manual is 72031. Tell them to search that number for you.

[BowTied]

It was a Parts Source, which is related to Canadian Tire stores.

 

Thanks Gianni, I will try that. If they do have a listing for they will not be able to order it in time for tomorrow though.

 

Can you believe they had no listing in their system for spark plugs? I got NGK platinums from NAPA at least.

[navygz19]

It was a Parts Source, which is related to Canadian Tire stores.

 

Thanks Gianni, I will try that. If they do have a listing for they will not be able to order it in time for tomorrow though.

 

Can you believe they had no listing in their system for spark plugs? I got NGK platinums from NAPA at least.

 

 

Good deal, the NGK's will do you well. I would always ask on here what a part number is for the Pathy before going to a local parts store...seems unless it's FoMoCo, Mopar or GM they don't have a clue.

[BowTied]

Ok, I got my gaskets earlier than expected!!

 

I did the whole job yesterday, my results with pics are here:

http://npora.ipbhost.com//index.php?showto...t=0#entry277573

 

Anyone else who has done this job and would like to add to my post, that would be cool with me.

R

[Aussie1]

Hi there. I am a 2004 Pathfinder LE owner and have been reading different sites and postings about this power valve screw problem facing the VQ35 engines. I know that the power valve screws are the main culprit here BUT after reading BowTied's posting on how to do the job with the power valve screws, he mentioned about the swirl valve's in his intake manifold, which is just below the lower intake manifold collecter/power valves. Do we need to be concerned about these swirl valves located inside the intake minfold, and the possibility of THOSE screws falling out as well? Or do we only need to be concerned about the power valve screws? The reason I am asking because its alot more work to take the intake manifold out, and there are more gaskets to replace, but if the possibility of those screws are likely to fall out as well, I think we should be concerned about those too.. wouldn't you say? Read BowTied's posting on how he did his power valve screws, and scroll down to where he is talking about his swirl valves if you need to see what I am mentioning about. Any comments or thoughts about this would be very appreciated. Thanks very much.

 

By the way... I have a Nissan FSM and I cant point out where it is exactly, if anyone needs me to. If anyone else need a picture of this, message me. Thanks.

Edited February 25, 2008 by Aussie1

[BowTied]

Yeah, I never really did get a straight answer on if the swirl valve screws are also at risk?? I hope not as it is a much bigger job, I think you need to remove fuel rails... I don't know if you need to drain coolant too or not?

 

The swirl valves are visible in the second picture of post #4 in my 'how to' post.

Edited April 17, 2008 by BowTied

[IncidentalOffroader]

VQ35DE owners with manual transmissions should read this post and check if they have any power valves at all.

 

Although you might not have power valves, there are still the swirl valves which you definitely have. So I'd still keep an eye on this topic in case it's determined they have the same problem.

[morpheus]

It seems like there's a lot of people asking a lot of questions here.

 

Let me set a couple things straight for everyone.

 

1) The power valve screw issue was NOT a large problem with the 3.5l. Did it happen on some? yes, most, no.

In all the pathfinders's I've serviced, I only had 1 of these happen to them.

 

2) The power valve screw issue with 2.5l sentra's and altima's WAS a problem, and a recall was issued on it.

 

3) Can you take your intake apart and secure them for peace of mind, of course you can, it's actually a pretty simple process (3 hours should be plenty of time)

 

4) If you are going to do this repair yourself, MAKE SURE that you only remove 1 screw at a time and thread lock it. The valves are percicely aligned, there is a special jig that is used to align the ones on the altima/sentra's.

 

5) The power valves and screws are NOT seperate from the lower intake manifold collector. Hence it makes it a power train item and is covered under the powertrain warranty.

The person with the 04 should still be under warranty, unless his 04 was registered in early 03

 

6) If a screw happens to fall out, chances are that it will simply embed it's self into the catalytic converter, where is may/may not stay. If it comes free, it can be sucked back into the engine and score the piston walls. If it simply goes in and out, it's unlikely there would be any damage, but if you are doing this repair and find a screw missing, pull your exhaust manifold off and remove the screw. Yes I know that's a tonne more work, but it's worth it.

 

7) any locktite should do, but I'd suggest red locktite. There's no reason you would ever need to remove the screws for servicing.

 

8) You should be able to re-use all the gaskets, unless any become damaged in the process, and in a pinch a dab of silicone gasket would get it back together.

 

9) Only Pathfinder's and QX4's with the 3.5 have the power valves. All other 3.5's (altima/maxima/etc) have a different intake design.

Edited June 30, 2008 by morpheus

[BowTied]

Thanks for the follow up Morpheus - are you a Nissan tech?

 

What is your opinion on the same screws in the swirl valves -should they be done too?

[morpheus]

Thanks for the follow up Morpheus - are you a Nissan tech?

 

What is your opinion on the same screws in the swirl valves -should they be done too?

 

I'm a service manager for North End Nissan ( www.northendnissan.ca )

 

I've only ever had 1 R50 with 1 power valve screw missing, and we replaced the entire power valve manifold section under warranty.

Edited July 4, 2008 by morpheus

[Simon]

Nevermind the haynes manual. They're crap.

 

Go to www.phatg20.net and download the proper factory service manual for your truck.

 

You'll also need WinRAR if you don't already have it to decompress the rar files. (works exactly like WinZIP)