IncidentalOffroader

I'm pretty sure I saw swirl valves in the lower intake manifold of my manual R50, just like in the automatics. I was following BowTied's write-up and was aware of the swirl valve question. So I'm nearly 100% certain I looked for them, and if I didn't find them, I would have reported that along with the absent power valves. I might have pictures to back up my memory, but we're in the middle of a cross-country move so all my stuff is packed up. How about this: assume that manual R50's have swirl valves, and if I find out otherwise, I'll re-post.

It really sounds like the needle is binding against the gauge's face. There was a discussion about this in http://www.nissanpathfinders.net/forum/index.php?showtopic=18369

Perhaps the accelerator cable is doing the sticking and not the throttle body. I've heard of cases where throttle bodies develop this groove in which the valve gets hung up. I think it was in reference to a Toyota engine. This is all hearsay on my part, but I repeat it only to suggest another cause of your sticky throttle.

x2 on the new wires, cap & rotor. They are definitely items that wear out and are part of a routine tune-up. Here's another longshot: Since you say the car dies as if you turned the key off, maybe your ignition key switch is flaky. It's not improbable, since people tend to hang a lot of stuff off their keychains, and that can't be good for the longevity of the ignition switch. A quick check would be to start the car, tap and jiggle the key, whap around where the ignition switch is mounted, and generally try and get the car to shut off without actually turning the key off. Since the problem you describe is so random, we're hoping all you need is to disturb it a little to repeat the fault. A longshot I know, but it's simple enough to try anyways.

OK, it's embarrassing to admit my experience in the matter, but here is my story. I too have cranked my 01 SE while it was already running. My excuse is that the engine is so quiet and smooth at idle (those liquid-filled engine mounts), that I couldn't hear it above the ambient noise and forgot it was still running. Worse yet, I clicked the starter multiple times before I finally realized what I was doing! The reason I didn't immediately know was because it didn't make that unmistakable grinding noise: just that buzzing noise you described. It didn't sound destructive at all, or I would have known right away. I also wonder if the starter mechanics on the 01's is tolerant of this abuse, (either by chance or by design), but of course I'm not about to experiment!

That's pretty old. Even the fuel stabilizer I use doesn't claim to protect gas beyond one year.

Normally I change my oil and filter every 3k miles. I put in 5 quarts. Typically I have to add another quart before the next oil change. This doesn't strike me as particularly bad, but maybe I grew up not expecting any better from an engine. I wish I could be more precise about the numbers, but my usage pattern has been too inconsistent. My last oil change was after only 1043 miles, but that was after 9 months. Since the last 2.5 years, we hardly drive it at all: it sits undriven for up to 3 weeks; I'll go up to 4 months between fill-ups (I have to spend extra on fuel stabilizer). The type of miles I drive are mostly short local trips, with an occasional long road trip. Some more relevant info: I have 51000 miles on the odometer. I use 5W30 as recommended. I use whichever national brand oil has a rebate going on. I don't use synthetic. I've been using Purolator or Fram filters (it uses the same filter as my wife's Accord, how lucky is that?!) I don't tow anything. I don't go off-road regularly (maybe 1-2 times a year). I am not Speed Racer all the time, though I have nothing against hovering around the redline for a few seconds.

Sorry, I don't know. Though I watched as the gearbox was removed and opened, I didn't actually have my hands on it. Can't say I'm an expert, but considerable play on your input shaft seems very suspicious...

ahh yes, the "melted speedo needle"... that brings back memories of my '87 Pathy. Over time the plastic needle would curl down and scrape its tip on the gauge face, possibly binding it. I would take off the gauge lens and bend it back up, but the problem would eventually come back. Finally I straightened a paper clip, cut it to size, and placed it on the backside of the needle to keep it from bending back. I kept the wire in place with a piece of clear tubing slipped over both needle and wire, and tacked it all together with a spot of silicone rubber adhesive. That fixed the problem, and it looked fine. The clear tube wasn't noticeable at first glance, and it looked like it could have been part of the original design. The next problem was calibrating the speedo after I took off its needle. The best way I could think of was to follow a buddy cruising steadily at a known speed, and placing the needle on the speedo so it would show that speed. (obviously the gauge's lens must be removed during this procedure). But that was more fuss that I wanted to deal with, so instead I measured my actual speed vs. the speedo speed and kept a mental note that the speedometer reads xxx MPH high or low. A handy way to measure your actual speed is to use a stopwatch and the mile markers on a straight stretch of uncrowded freeway. Cruise steadily at freeway speeds. Start the stopwatch at a mile marker, and stop it at the next mile marker. Don't change lanes. Try very hard to keep a constant speed during that mile: keep the speedo needle at the same place (it doesn't matter exactly what it reads, just that it stays in the same place). Your miles per hour is the 3600 divided by the stopwatch time (in seconds). ex: 60s=60MPH, 62s=58MPH, 55s=65.5MPH. I like this method because you can do it yourself, anytime you are bored on a long drive down the freeway.

I had the exact same symptom the first time I had my gearbox rebuilt. Along with some other worn bearings, one of the bigger bearings was obviously shot: the bracket that held the balls spaced apart in the race had gotten chewed up. Strips of jammed metal were hanging out of the bearing when we got to it. I don't mean to cause you to panic, but that was just my experience. Before I had it opened up, friends were telling me that manual gearboxes typically don't fail suddenly and catastrophically (as opposed to automatics), and I could drive it around until serious problems started showing up. But since I needed reliability at the time, I opted to have it taken care of. The second time I had my gearbox rebuilt there was no obvious specific problem like the first time, and I believe I could have driven it for a good while longer. You might get lucky by simply topping off the transmission fluid and/or using an aftermarket additive as Simon suggests. It all depends on your risk tolerance.

Ghosty, your explanation makes it all come together now. Though I'll have to take your word for it on the length of intake path vs. HP vs. torque... that's way beyond the scope of my knowledge! Who knew that owning a VQ R50 would be such an exercise in manufacturing forensics?! Add this to what I had to go through with the ignition coils.

Add to that, check any relays leading up to the solenoid. I had an 87 Pathy that would go "click" very intermittently, sometime years in between occasions. I replaced the starter several times, figuring they were poorly re-manufactured. Finally I thought to check the relay that drives the solenoid, and found it had, like 7 ohms across it's contacts (let's say the solenoid takes 1-2 amps, this would be a 7-14V drop: no wonder the solenoids were unreliable!) . The relay was <$20, plucking it out of the relay box was literally easier than changing a light bulb, and most importantly, I never had the starter go "click" again.

You did a great job, and I think many more people have or will use your post than you'll hear from. Any given forum will have many times more lurkers than regular posters. However, I do believe it's good practice to at least send a private message to the author if I found a HowTo useful. A pat on the back will also make the author more inclined to share in the future. Even a simple "Thanks, Dude! You da man!" private message can make a big difference for the entire forum ecology!

I had an 87 Pathfinder that would sound like that. It would do it when the gearbox bearings were going bad. The noise goes away when the clutch is depressed. I've twice had to rebuild that gearbox, basically to replace bad bearings. The first time the noise built up gradually over a few weeks until I finally fixed it. The second time the noise started abruptly: before making a dinner stop it was fine, after dinner it was making an obvious noise that could be heard at highway speeds. Hopefully this isn't your problem, cause if it is, you'll have to drop your clutch and t-case again.

I found this guidance very helpful. Thank you, BowTied The entire job really isn't that bad, one just has to be methodical about a system for remembering how all those hoses and clamps get re-installed. I really liked that idea of pushing the bolts through cardboard to keep them in order. I ended up taking off the resonator box under the intake hose. It really did make life a lot easier. Rotating the clamp on the box's connection to the intake helped me actually see the screw head. I used an offset ratcheting screwdriver in the tight space, though one would incur just a little more fuss with a regular screwdriver. I had a bit of trouble with the weatherproof electrical connectors. The FSM has info on how to unlock them, but I couldn't get the knack of it. Sometimes it took me almost 10 minutes of fiddling before they finally came apart. My advice is to NOT force the connectors apart: when they are finally unlocked, they come apart with almost no force. Before delving into this procedure, 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.

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.

There is a TSB for the 2002 Pathfinder that includes reprogramming the ECM in case of rear O2 sensor DTC codes. The TSB# is NTB03-011. I had my ECM reprogrammed for my 2001 Pathfinder (called for by a similar but different TSB# NTB02-006.) It fell under the long-term federal emissions warranty of 8 years, so I wanted it done free. The dealer wouldn't do it without changing the O2 sensor also, which is no longer under its warranty. But we made an agreement: he'd do the ECM for free (0.5hr labor), and I'd give him top marks when I got the customer satisfaction survey from Nissan Corporation. I should mention that the dealer was also going to take care of the fuel filler tube recall at the same time, so ultimately the dealer will get money out of my service visit when he charges Nissan for the recall work. I believe the rear O2 sensors aren't used in the engine control loop. They're just for monitoring the health of the catalytic converter. As such, low miles-per-gallon problems aren't due to bad rear O2 sensors. The rear O2 sensors are easy to access, but have you seen what you have to go through to route the cable to the connector? I'm seriously thinking I'll use the cheaper universal sensor and splice it to the existing cable. I think splicing would be easier than routing. Maybe that's part of the huge cost your dealer quoted: properly re-doing those all cable-mounts has got to be labor intensive. And since the rear O2 sensors aren't used for controlling the engine, there should be no performance degradation issues we sometimes worry about when using non-OEM parts.

I'd be skeptical myself if I hadn't seen the absence of the power valves with my own eyes. I don't want to hijack your thread, so meet me at this new thread I started and I'll show you pictures!

There are no power valves on VQ engines mated to manual transmissions. The screenshot below is from page EM-10 of the Nissan FSM for either the 2001.0 or 2001.5 Pathfinder. It shows the upper (8) and lower (2) parts of the intake manifold collector, and the throttle body (10). The "Variable induction air control valve control actuator" (14) controls the power valves in the "lower intake manifold collector" (2). The actuator has a note, "A/T", which I take to mean automatic transmission. (If you have a VQ/manual transmission of another model year, you should double-check with the corresponding page in the proper FSM.) Here is a picture of a VQ in a 2001 Pathfinder SE 4WD with a manual transmission. The plastic cover has been removed and nothing else. Compare this photo with BowTied's first photo in http://npora.ipbhost.com//index.php?s=&amp...st&p=277553. In BowTied's photo, the power valve actuator is the round thing with the hose at the lower left. In my picture above, the actuator would have been in the red box. The missing actuator is consistent with the FSM, and implies that there are no power valves. Here is definitive proof: a picture of the lower intake manifold collector. Compare this to BowTied's 7th photo in his write-up. There is no trace of power valves having ever been there. There even isn't a crossbar for the valves to mount on, nor holes in the manifold body for the crossbar to run. Hope I've saved other VQ manual transmission Pathfinder owners some time and worry. An unresolved question: is there a different part number for VQ35DE engines for manual transmissions? This would be relevant to anyone wanting to do an engine or transmission transplant.

Answer: Kyle saw nothing. There were no power valves in the lower intake bypass ports. Apparently there are no power valves on VQ engines mated to manual transmissions for this year of Pathfinder. See the next post for supporting info. Mentioning the clutch and shifting from first gear were the clues to realizing that Kyle's Pathfinder had a manual transmission. This story is based on a true event. (Does anyone need any thread-locker compound?)

-OK all you VQ engine owners, see if you are knowledgeable enough to solve this riddle. -The answer is in the second post. -If you don't have time for riddles and want to cut to the chase, skip to the third post. -Those who have been referred here by the "Highest Milage/Oldest VQ, Problems w/VQR50's" thread will already know the answer. The riddle: Kyle finally carved out a weekend for checking out the power valves in his Pathfinder. There was a manufacturing defect where some VQ35 engines did not have the valve mounting screws secured with thread-locker. The fix was simple, but labor intensive: remove the upper part of the intake and apply thread-locker to the valve screws. As he eased off the clutch and slowly maneuvered his 2001 Pathfinder SE 4WD into his work area, he thought how lucky it was of him to have joined the NPORA forum recently. Otherwise he would have never known about this issue, and could one day have had a sudden catastrophic engine failure. In fact, some screws may have already fallen out, and the implications were just too disturbing to consider. Yet again, it was quite possible that the screws were adequately secured and there was never any problem, in which case ignorance would have been bliss. With mixed feelings over the value of having too much information, along with a feeling of suspense over what he would find, he shut off the engine, shifted out of first gear, set the handbrake, and started the task. Kyle worked methodically, guided by the Nissan FSM and an excellent write-up of the procedure by BowTied. He had never gone so far into this particular engine, so he went slowly. But he was having fun. He also thought of the money he was saving by doing the work himself. Finally, he unscrewed the last bolt holding the upper intake and lifted it. The moment of truth had arrived: would he see the power valves all securely held in by their screws? Or would he see missing screws, or even missing valves, like one of the more shocking photos that was on NPORA? He looked down at the lower intake ports where the power valves were and was astonished to see.... What did Kyle see? See the next post for the answer.

? I think mzxtreme means "approximately average".

Ummm... I know this sounds like I don't know what I'm talking about, but I really don't have any power valves in my upper intake manifold. I figure it's because I have a 5spd. The 2001 FSM, pg EM-10, shows a "Variable induction air control valve control actuator (A/T)" that my VQ does not have. I'm assuming (A/T) means automatic transmission. I don't want to stray off topic, so if anyone wants to discuss this further, or see pictures of my power-valve-less VQ, PM me and I'll start a new thread.

2001 SE w/ VQ, 51k miles Repairs: Replaced ignition coils. Reprogrammed ECU for rear O2 sensor issues. Rear O2 sensor failure. No power valve issue (manual trannys don't have power valves).

I looked into this myself recently and ended up using a cassette adapter. There's no installation to speak of, the sound quality is good, there are no interference or noise issues, and it's inexpensive (I've seen them at Target and Pep Boys for about $10.) If you don't have a cassette deck (I have an 01 Bose, perhaps they did away with the cassette deck by 03?), you could try an in-line FM modulator: http://www.crutchfield.com/App/Product/Ite...OD01&tp=121 Since it is in-line, there are no transmit/interference/reception issues that plague FM transmitters. It must be installed, however. Crutchfield also offers Ipod-specific products that might charge your unit also. I don't use an Ipod, so I don't know any details.