Slartibartfast

The early VQ40s apparently had timing chain tensioner issues. Does it sound anything like this?

From what I've read, the transmission out of an Xterra, R50 Pathy, or Frontier should fit the WD21. Also the post-95 five-speed transmissions had a higher oil capacity to prevent the oil starvation issues of the older ones. I think it was Adamzan who put an Xterra auto trans into his WD a week or so ago, said it bolted right in.

If you connect a ground wire and it heats up and smokes, chances are it's not a ground wire.

Sounds like the Goodyear requires lower pressure than the Winstons, and so (even at the same pressure) is overinflated. The ideal fix would be matching tires, but airing down the Goodyear might work for while. Driving like that is a little sketch though. You said this happened with your last set, was that set also mismatched?

The engine bay wiring does vary slightly auto vs manual (different relays and a dropping resistor for the AT). I think the harness itself is the same and ends up with a few unused plugs depending on which version you have. If the replacement harness is in good condition (look for corrosion in the connectors as well as screwed up wires) and saves you a few nights of splicing wires (and possibly more wiring issues down the road) IMO it's not too bad of a deal.

I run 35, 30 feels squishy with my tires. Depends on sidewall strength. Odd that only the one tire is wearing though if they're all at the same pressure.

I have wondered if the carrier from an Isuzu or something (one of them that hinges on the driver's side so you can load/unload while parallel parked) could be adapted. I imagine the brackets would require some reshaping to fit the profile of the panel, and then you'd need to make a plate to go behind, and then rig up something with the latch. How hard could it be?

That's your pressure check valve from the tank. if that's what the line goes to, it should go to the carbon canister. Basically the gas in the tank expands with heat and the vapor has to go somewhere, so it goes out that line, and the carbon makes it smell less. The check valve closes if you roll the truck so that the fuel doesn't leak into the engine bay through the line. At least that's how it works on the gas model, the diesel might be different.

Yeah, that's not normal, and puzzling for a vehicle with a solid rear axle. +1 on the pressure, if the tire place used the same rim when they swapped the tires, perhaps there's a crack in the rim or corrosion on the bead making the tire lose air and wear faster? I had a corroded bead on my right front tire but I don't do enough driving to notice any change in tire wear. I think the tire shop charged less than $20 to clean the rim and re-seat the tire. LSD shouldn't do it, or if it did it would be on both sides. Just to clarify, this tire's wearing faster than the one on the other side, correct? Not just faster than the one front tire?

Sounds about right.

I'd be surprised if the parts store had them, but the wrecking yard probably does, and you might get un-chewed rubber bits out of the deal too. A while back Rob posted pics of a Murano intake that rats had filled with dog food. The owner quickly discovered that valves don't like dog food.

The clogged cat theory sounds good. Is there some special OBDII test that could verify this via O2 readings or increased fuel delivery? We'll do a smell test on the oil and see if we can detect any gas. Dad suggested having a used oil analysis done to confirm blow-by, but given how much fresh oil we're adding, would the oil stick around long enough to be worth testing? Given that the cats run about a grand just in parts we'd like to be sure they're the problem before buying new ones. I've heard of the Maxima guys punching out their cats and putting the second O2 sensor on a spark plug anti-foul spacer to make the computer think everything's normal. We have no emissions testing around here obviously, and given how much oil's going through this thing I'd be surprised if the cats aren't in a bad way already. Even if the computer threw a low catalyst efficiency code, would that make it quit dumping gas? I would like to check the valve screws just to be sure. Two questions on that. First, if we pull off the upper intake and find bits missing, should we assume the motor's shot? And after checking/loctite, can we get away with re-using the gasket? If we do solve the oil consumption it'll likely get new intake gaskets and a new PCV just to be on the safe side, but until we know there's hope for this engine we'd rather not throw new parts at it.

The throttle flapping's long since solved, it just needed a new swirl control solenoid valve solenoid something or another. Are you suggesting the cats in relation to that or to the oil consumption? I've read about Maximas with the smaller VQ sucking bits of catalyst into the cylinders (some kind of passive EGR via the exhaust valve timing) and destroying the bores/rings, but I've never seen it mentioned in relation to Pathfinders. Doesn't mean it's not possible though. We haven't checked the compression or valve screws on it, mostly because it looks like we'd have to remove an awful lot of stuff just to get to them, and it's Dad's daily driver so it can't be torn apart for long. However, the possibility of the rings sticking is interesting (and not unlikely of the PCV's been dumping oil into the intake). I found a post on a VW forum from a guy who said that filling his cylinders with carb cleaner, letting it sit a while, and then pumping it (out along with gobs of carbon) fully stopped his oil consumption. We'll have to look into that... it would be nice if the problem's that easy to solve. In case it isn't, any pointers about how to find a good replacement?

Well, I'm surprised. The more you know... There's a thread on posting pics but basically you host them somewhere else (flickr or photobucket or something), copy the direct link to the picture, then click the picture icon above the bit you type in (it's under and to the left of the smiley, looks like a tree if you look closely) and paste the link into the box that pops up. Then hit enter and you've got a picture.

I asked because reverse is usually the first to fail in these transmissions. If it was slipping I'd suspect that overdrive might be slipping too and triggering limp mode. Could still be that but it could be lots of other things too. Any luck getting a code? Live drive? I think mine sits somewhere around 2500 at 60 with the overdrive on, on level ground, closer to the 3500 when it downshifts to third (I don't spend much time going 60). Torque converter lockup factors into the RPM vs speed as well, but I don't understand it well enough to explain it.

Disclaimer, I don't have tons of experience and I didn't start with a rig needing that much work... but I do read too much stuff on here and remember a fair amount of it, so here goes. It sounds like you've got a clean shell with interior/drivetrain/wiring that are in bad shape. You might save yourself some aggravation (and have a nicer final product) by finding a lower mileage parts Pathy with a rusted out frame or body damage or something and swap over its interior/electrical/mechanicals. Or you could get the harness/interior from a wrecking yard and find a VG33 for it out of a Frontier, Xterra, or later Pathfinder, and end up with a more powerful truck than you started with. If you decide to rebuild your trans, it may need bearings as well as syncros. The oil level was too low from the factory, so some of the bearings don't get enough lubrication, which tends to make it whine in higher gears. If you decide to go for it, we love pictures here.

The VG30 in the WDs and the VG33 in the early R50s are quite similar. I don't know for sure that the thermostat housing is the same between them but I'd be surprised if it wasn't.

One of my cousins uses Torque and he seems pretty impressed with it. If I ever replace my flip phone I'll have to check it out. The consumption's getting worse. About 1100 miles after an oil change, it came in more than two quarts low. Dad's priced a new engine (more than he wants to spend on this thing), and a rebuild would cost more due to the shop time involved in getting into the heads. I'd love to have a go at it but it's way beyond my skill level. The crazy thing is, it still has plenty of power and drives fine. My research suggests that the later 3.5s (05-06) didn't have this problem. Does anyone know if these mate to the R50 Pathfinder trans?

Good idea! I should probably have a piece of hose in my emergency kit anyway.

Yup, there's a TSB on overfilling the trans to keep the bearings happy (referenced earlier in this thread).

Unless you've been doing a lot of towing, the fluid smells burned, and/or your last fluid change came out black and chunky I doubt the fluid's the issue. Wouldn't hurt to recheck the level (warm), apparently these act up if overfilled. How's reverse holding up? Limp mode for these transmissions is to lock into third, so if the trans computer saw something weird when you were in overdrive, it may have just shifted down into third by default. Then you pull off the highway, stop, and try to get going again, and it's still in third, which I think is probably the hesitation you're feeling. Restarting clears the code and you get gears again. I don't remember what all puts it into limp mode but I imagine anything from overheated fluid to slipping clutches to a loose connector could do it. IIRC a few guys have had theirs go into limp mode from doing doughnuts in the snow... the computer doesn't know wtf is going on and assumes the transmission is broken. Because yours happens while cruising it does sound like something's wrong. The next time it acts up, before shutting it off (if you can), check it for codes (the procedure's in the service manual, basically the light in the Power Mode switch flashes to tell you what's up). Hopefully that'll point you to the circuit or component that's malfunctioning.

Good to hear it's moving along! "Terrano, have you, uh, ever been arrested?"

Well now I feel like a weakling, I was beating on mine from every possible angle like a pissed off toddler and all I managed to do was engage the steering lock.

There was a light-duty Nissan winch available that fit onto a version of the brush guard--IIRC ahardb0dy posted brochure pics of what that looked like. So it has been done. I also remember seeing a carnage shot on here from somebody who tried to pull his rig out of a mudbog by the top rail of the guard and tore the thing completely off the truck so clearly there's room for improvement. The little (10mm?) bolts holding the guard to the bumper brackets look like a weak point. Also I'd be concerned about the brackets themselves bending under side loads (if you winch at an angle). Make a second set of mounting tabs for the guard (inboard from where the tabs are now), beef up the brackets to hold the new bolts and brace side-to-side, and IMO you'd have the top more or less solid. Bigger bolts would probably help, too. The bottom looks like it's connect by a single bolt per side as well. I'd want to beef that up too, and not because the bolt would go, but because it's got a spindly little connection that can kink in the middle (especially, again, under side loads), which could allow the whole mess to pretzel and tear away from the top mounts even if the bolts themselves don't give out. Again, you could probably build better brackets for it. Or it might not be an issue at all, I don't know. Then there's mounting the winch itself. If you put it between the guard's mount points they'll share the load; if you put it on top of the bumper you'll put a lot more stress on the top mounts. Kind of depends on how you mean to use it and how much trust you have in the upper mounts. It would never be as good as a proper winch bumper, but for a lot less money and a little work it would probably hold up to light duty stuff. I wouldn't try to climb any trees with it though.

And the "now what?" when those systems fail without throwing codes!