Slartibartfast

Nissan was still running the VG33 in 2000, so if you're looking for an engine, that's not a match. The R50 LSDs were nerfed hard from what they were in the WD21. Hawairish has an excellent writeup for repacking the R50 LSD to be worth a damn. The early (first couple years IIRC) Xterra LSD is supposed to be a drop-in upgrade if you don't want to tear the diff all apart, but you do need to check the gear ratio and make sure it matches the front end. @Camperdan, thanks for the correction! Shows what I know about the VQ35.

That's a good question. A used engine/trans would be easier (and probably cheaper as well!), but might have its own issues--like I mentioned, some of the early VQs had oil consumption issues. (I've heard various theories about what actually goes wrong--PCV design, cylinder taper, catalytic converter bits getting sucked back--but I don't remember reading about someone with the oil consumption actually fixing it. My dad's '03 burned a quart/1k miles before 100k, and it acted like the valve stem seals were bad, but we never tore it down to see what was wrong with it.) Rebuilding yours (or a donor engine) may get you a better product, assuming you don't mind the added cost and time, and of course assuming you have the skills to pull it off. Also consider compatibility. Nissan changed a few things across the four years the VQ was used in the R50. '01 and '02 were both cable-throttle ('03-'04 were drive-by-wire), but IIRC the '01 had different valve covers and coil packs? I would expect '03/'04 engine to work if you used your old intake, but I don't know that. Do some research on this to make sure you get the right stuff. It'd be great if a more modern VQ (with the early bugs ironed out?) would work, but that sounds like a science project waiting to happen--who knows what else they've changed in the last twenty years. Unless you've got the five-speed (rare with the VQ, but they do exist), I think all the VQ R50s got the same four-speed auto. That one should be simpler to track down.

Good work! Those smoke machines are nice. At 300k, I think longevity is going to depend more on how well the last owners looked after it than anything else. I would loctite the power valve screws while it's open, they have a reputation for working loose and falling in. Keep an eye on the oil level once it's back together! Some of the VQs are oil burners. The cable-throttle VQ R50s also have an idle air valve that can leak coolant into itself and blow up the computer. I don't remember if it's just the gasket or the valve itself that goes bad. Something to look into.

It's been a few years since I researched tires, so I'm not familiar with either option. That said, "better" will depend on how you intend to use them. I'm running Toyo AT2s on mine. Soft compound, good traction in snow, good traction on dry roads, but faster tread wear than some options. I don't put a lot of miles on my truck, so the tradeoff was worth it for me--I figured the dry rot would kill them before treadwear did. Six-ish years later, they're showing a little wear, but no dry rot yet, despite starting to get a little long in the date codes. (Check the date codes--mine were two years old on delivery, which probably explains why they were cheaper through that particular retailer.)

I don't know about the poly, but I would climb under and have a look at the bushings while someone pushed the back of the truck side to side. Should show you pretty quick how the panhard bushings are holding up.

The trouble I've had with cheap worm clamps is mostly due to soft metal deforming. Bands stripping, worm housings opening up and letting the worm skip on the band instead of tightening it, worms coming out of the housing when I try to loosen them. I have yet to find a clamp that doesn't leave some impression on the hose, though obviously the fuel-injection-style clamps are easier on them than the standard worm-drive. I'd say the one in the picture was on there pretty tight, but I don't see any cracks or tearing, so I would not assume that the hose was compromised. I don't see a second impression from an earlier clamp. At the 13 lbs the rad cap limits the cooling system to, I would expect a properly spec'd spring clamp and a properly tightened worm or wire clamp to be functionally identical. I would not expect the steering return to be much higher, as all it's doing is lifting fluid a couple of feet and dumping it back into the reservoir. (The steering pressure line runs over 1k psi at idle, so it's not assembled with hose clamps.) I'm not sure what pressure the trans cooler runs. IIRC it feeds a lube passage in the trans, rather than just dumping right back into the pan, so I imagine it's got a little pressure behind it. I ran a plastic external trans filter on mine for a while, and it didn't explode, so clearly it's not too awful high. I understand the advantage of spring clamps for thermal expansion. Personally, I have an easier time trusting a clamp that I remember tightening than one that I just sorta let go of and hoped for the best. Looks like there's a hybrid of the two clamp types out there, too. Looks like a standard worm clamp with a stack of Belleville springs between the worm drive and the housing.

Yeah, that doesn't sound good. Not sure why it would have a layer of clean oil at the bottom, though, that's bizarre. Are you sure it was oil and not water? Not that water in the pan is better news.

The wire ends overlap each other, so as you spin the bolt through the plate, it pushes the washer and the plate apart. Because the ends of the wire are overlapped, pushing them apart pulls the clamp tighter. It's a neat design, and they seem to hold tension just fine, but the wire is the only thing preventing the plate from twisting, so they're tough to free up when the threads seize. Brute-forcing them just bends the wire all to hell. Holding the plate with vise grips or a Crescent wrench may help, if you have access. I am not fond of the spring clamps. Sometimes they're just a little bit too small with the tabs clamped together, so you can't get the hose over the nipple. Sometimes one tab slips out of the pliers, and the clamp spins itself around so the tabs are behind something, so you can't get the pliers back on it. Sometimes they slip out of the pliers and ping across the shop. I imagine they're a little less of a drag if you've got the special pliers, which I don't. (Probably should, now that I think about it.) IIRC some of the wire clamps on mine did not come apart in one piece, and I was annoyed enough about it that I switched everything over to worm clamps. They're a lot easier to work with, they work on a wider range of sizes, and they don't tend to seize up. That said, they can tear stuff up if overtightened, and I have worked with some cheap ones that were inexcusable junk.

I would be surprised if R51 hinges worked. Wrecking yard is probably your best bet. I'd try JB weld in the meantime, if there's enough left to try and glue back together.

Does anything else turn off with the key? Radio, blinkers? I'm wondering if the ignition switch is buggered. You could remove the clamshell and unplug the switch, see if that shuts it off. If it does, then you know the switch is roached. Ignition relay's a good check too.

If you disconnect the shaft at the rear end, and strap it up, then it should be OK. If you take it out of the transfer, then, yeah, it'll puke everywhere.

EL doesn't show the circuit, but it does show (roughly) where every electrical plug in the truck is located, down in the harness layout section. The '90 manual shows 211M below the fusebox, A pillar/driver's kick panel area as level9 described. The '95 manual shows it on the passenger's side. Probably a round-dash thing. I would expect yours to match the '90 manual. This is what the breaker looks like, if that helps.

The VG33 is pretty reliable. Timing belt should be done if you don't know when it was done last. There's a writeup here, and you can get the service manual from Nicoclub, which will also explain how to chase that P0115 code. P0300, might need a general tuneup. Maybe clean the MAF and throttle body while you're in there. Standard fluids/filters. I don't see rust in the picture, but I'd have a poke around the front strut towers to be sure that they're solid.

Go through your fuse box, see if you've got one blown. A blown fuse is likely a symptom, rather than the cause of the problem (they don't tend to fail on their own), but it's a place to start.

They do look quite similar. Part numbers are similar, too. The '99 pump is 49110-0W000, '05 Fronty is either 49110-EA000 or 49110-EA200, depending on engine option. Should be different flavors of the same part. I don't know that they have the same pressure relief valves or fittings, but you may be able to swap bits over from your old pump to make the new one work if it's not completely roached.

Shame about the Tundra! My dad's got an '01. Solid rig. I don't know the R51 Pathfinders all that well. Some had a bad trans cooler in the radiator that would leak internally and cause the Strawberry Milkshake of Death (SMOD), but I think that was more in the earlier years. I would still read up on that and check that there's no milkshake/mayonnaise in the radiator or the coolant overflow.

I want to test the spare amp vs the one that's in mine to make sure it's good before I box it up. But, yeah, it's not doing me any good gathering dust on the bench. PM me and we'll sort it out. Might be worth checking the diodes on yours, if your meter has a test mode for that. They can fail open or closed (or fail closed and then burn open), and I imagine either condition would play hell on whatever logic circuit they were part of.

I had a look on nissanpartsdeal. 55130-4W000 is listed for '00-'04, 4WD/AWD. 55130-2W100 is listed for '98-'04, 2WD and P/4WD (which I assume means part-time 4WD, not the AWD/all-mode). I suspect someone screwed up the data entry, and the 2Wxxx part number is for 2WD, and the 4Wxxx part number is for 4x, because why the hell would the panhard bar care which transfer case you have? Then again, why would it care if if it's got a transfer case at all, unless they did some weight savings on the 2WD variant, assuming it wouldn't be beat on as hard. I found one other part number, 55130-0W000, for the VG33 trucks and some VQs. The site says it's incompatible with yours, assuming you've got the AWD/all-mode transfer. Pictures of the three variants show different whatsits along the bar (which I assume are vibration dampers). I don't know that this is the only difference between them, but I also don't know that it isn't. Listed weights and dimensions vary a little, but there's no indication of what exactly they were measuring, so I'm not sure how far to trust those numbers. Could be one guy measured between centers, another measured overall, and the third measured the box the part came in. Could be they're all slightly different lengths and widths, just to be that way, but then they'd also have three different axle housings and/or three different panhard brackets, and I have no idea what slight changes to the dimensions of the panhard would've accomplished anyway. That said, Nissan does do stupid things sometimes. I'd be hesitant to put $200+ on my hunch that it's all the same part but with different unimportant dangly bits tacked on. +1 for checking the wreckers. Even if you don't find the right one, the wrong one from a wrecker should be a much cheaper experiment than the wrong one brand new from Nissan.

It's amazing how much room a parts car takes up once it's taken apart.

If you can work out what kind of plug it is, you may be able to find a pigtail for it, and make up a patch harness to avoid modifying either the truck harness or the compressor. Sometimes the pins in the plug will accept a standard size of spade terminal, but of course you want to make sure it's a tight fit that won't overheat or rattle loose.

No worries! Sounds like a fun build.

Nice two-tone! Check for yourself that the parts are actually bad before taking Les Schwab's word on anything. Check the steering box, too. My dad had every joint in the front end replaced on my '95, and the steering didn't feel any better afterwards, because the slop was in the box. They are technically adjustable, but I killed the box in my '93 by attempting this, so I do not recommend it. I replaced it with a VisionOE/BBB reman off Rockauto, which I also do not recommend, because it's worse than what I started with. I'm planning to replace it with a used one that hasn't been worked over by muppets. A few people have had theirs professionally rebuilt by Redhead--sounds like that's the way to go. The stock centerlink on these is not a great design. If you're keeping the truck at stock height, stock tires, and not wheeling it, then it should be OK. Seemed to hold up OK on the '95. I've got a Grassroots link on the '93, which I don't think I could break if I tried, but it's scared me a couple times from the fasteners working loose (though fine-thread fasteners are supposed to cure this). It's also got a lot more drag than the factory parts. I didn't like that at first, but now that it's worn in to where it self-centers again, I appreciate how the added drag mostly stops the front end from exploring the play in the steering box. Unless they're damaged, the wheel bearings can be repacked and readjusted. There are instructions in the service manual. Cardiagn.com has the '90 manual. Do the seal between the hub and the CV while you're in there. Add the strut rod bushings to your list, even if they look okay. The cups fail, the holes wear oversize, the sleeves wear through, and then the rods wear through. IIRC I tracked down 555 parts through Rockauto when I did mine. Some of the boots haven't held up as well as I would've hoped, but I haven't noticed play in the joints yet. I was told at the time that it was a good brand. Don't know if that's still the case.

From what I've read about what goes wrong on VQs, I'd loctite the power valve screws while it's torn down. IIRC there's a coolant pipe between the heads at the back, with a second thermostat, that's a pain to access normally. Same story with the PCV valve. Valve cover gaskets probably need doing. And you already know the cooler is leaking. The service manual is likely your best bet, but the power valve screws writeup may help for the intake disassembly. Nissan used (and still uses!) the VQ in a few other platforms, so you might find a writeup or even a video for a more popular model using the same(ish) equipment. I wouldn't use this in place of the manual, but it might show some work-arounds for special tools, or other things that you should check while you're in there.

Spark testers use neon bulbs designed to work at high voltage, so, yeah, no good for 12v. You can make up a test light pretty easily with a 12v light bulb (194, 1156, whatever's handy), a test lead you don't mind cutting in half, and a soldering iron. And yeah, I had assumed that was a banana jack or something too. Nice that they couldn't be bothered to label it. Mine clicked once when I hooked up power, then clicked again when I triggered pin 6, and did not click off until I disconnected power. If yours has power across 2 and 4, when you haven't triggered pin 6, I'd call that a smoking gun for the amp.

Oil in the coolant is never a good sign. Bizarre that the blue schmoo in the coolant would slow the oil loss, though. I diagnosed a head gasket on a neighbor's Toyota last year. No clouds, plugs looked OK, no obvious misfire, though he said it felt down on power. I got an occasional bubble out of the radiator with the cap off, but wasn't sure I'd bled it right when I'd refilled it, so I wasn't gonna call it just from that. The smoking gun was when I put compressed air to one of the cylinders (like you would with a leakdown tester, except I didn't have one, so I just used the air nozzle) and the air just boiled out of the radiator. The combustion leak test should tell you the same thing. A failed cooler could explain the oil in the coolant, but I don't think it would explain where the coolant is going.