GhostPath

VG30 crank pulley assemblies are polarized with a key and cannot be installed in other than their correct orientation. What's probably happened is that the pulley has delaminated from the harmonic balancer. They're attached to each other by rubber and adhesive, and when the rubber starts cracking with age, the pulleys start to slip and your timing mark wanders around. Harmonic balancer/pulley assemblies aren't very much on the aftermarket - I see them for $35-75 around here and a dealership will have it for somewhere around $160 or so. They're sold as a unit, not separate pieces. If you replace it, replace the Woodruff key or "keyway" as Nissan calls it at the same time to avoid crank wear. Alternately, the key may have sheared off or the key slot wallowed out, which would allow the pulley to rotate or slip separately from the crank. This is a somewhat common issue, especially on VG30s that are ineptly serviced. If the key has sheared, you might be able to get away with just replacing the key. If the slot is wallowed out... well.... there's lots of bandaid fixes, but the only right way to fix it is to replace the crank.

I don't have the manual here in front of me, but I believe that it's across the pins.

I edited my response, reread my prior post for more info. Yes, you test it for resistance/continuity. A bad TPS or bad TPS wiring could cause what you describe.

You can test it for a bad spot in the range of motion... BUT. Sometimes a bad one will test good because you didn't hit *just* the right spot while testing. The TPS is considered to be a consumable/wear part anyway. Eventually they wear out; 13 years is a decent run for one. I'd just replace it. Dealership wants less than $100 for it. Alternately, you could get the TPS (used) from a lower-mileage truck that died from unrelated reasons - all the WD21 MPFI V6 trucks use the same TPS. Correction: All automatic trucks use the same TPS, all manual trucks use the same TPS. You cannot use a manual TPS on an automatic truck.

The TPS is testable, but it isn't servicable in any sense. Service is by replacement only.

Huh. Well, there you go!

Are you sure those are the monotubes and not the twin-tube cheaper versions? Bilstein makes both...

Do you even read the posts you reply to? This is like the third time I've caught you out like this... http://www.courtesyparts.com/Merchant2/mer...Code=22630-VG30 (Despite what it says, that's the correct one for all the WD21 Pathfinders, IIRC) The part number for the 90 SE-V6 is 22630-01P01, and it cost me $24.66 from my local dealer with my Z Club discount. It takes about 15 minutes with a deep socket to replace it, including draining off about two quarts of coolant. O2 isn't going to cost much, but the MAF is going to be shockingly expensive.

The transmission control computer may have died, or the connector may have come off the transmission... Usually, though, the transmission dies and has to be replaced. They usually give some warning ahead of time, though. Mine did, it started slipping in OD, then 3rd, then it lost those two entirely.

Check to make sure the shift linkage didn't fall off the transmission?

http://www.courtesyparts.com/Merchant2/mer...ode=WD21-TBKITB Add to that a new crank sprocket, keyway and maybe the Nissan silicone (which is neat stuff) and you're all set.

My guess is that you have a u-joint on one of the driveshafts going south. Failing that, could be an axle or wheel bearing.

If you're going to keep it stock height and do mostly road driving, get Bilstein HD monotubes. They're best on road and apparently pretty good offroad. And a set of four is $350 or so on eBay.

Umm.. timing belt needs to move to "do it now." The timing belt is supposed to be changed every 105K on your model. Nissan's not kidding about that, either. If the timing belt goes, you either rebuild your engine or install another one. If your thermostat is broken, chances are good that your water pump is going to go soon, too. If that goes, you get to do the timing belt, assuming that the belt doesn't go right away. Your Pathy is telling you "do the maintenance or I'm about to get really expensive".

The Pathfinder's got a nice, spacious engine bay compared to many, many GM products. GMC Syclone: Olds Intrigue: Well, the belts are a wear item, and you'll probably have to remove them to get to the thermostat. By the way, how many miles are on the truck and when was the last time the timing belt was done?

Oh wait, yeah, the thing's in the front of the engine, isn't it. Still, not a problem, actually. You just have to take the fan off, that's all.

If I recall correctly - it's been a while: Drain coolant, remove upper radiator hose, remove thermostat housing, replace thermostat. Also, do you have the manual or the automatic climate controls? The manual control set has the typical red-blue slider indicator for temperature, the automatic has actual numbers written on the temp slider and is ranged in blue-gray-red.

You can test it with a multimeter and a precise thermometer, but it's only $25-30 from the dealer. It does eventually fail, the thing's old enough, so I'd just go ahead and replace it. While I was looking at it, I would look carefully at the wiring that goes to it. On the Z cars, that wiring is a separate subharness (costs about $10, no idea if the Pathy has the same deal) because the connector there tends to corrode and the harness gets abraded. Make sure the connector's terminals are clean and bright and that there are no breaks in the insulation in the harness. If the connector or the first inch or so is damaged, it's a standard Bosch fuel injection connector and you can splice a new one in - they're available at any auto parts store for about $5. What the coolant temperature sensor (often called the cylinder head temperature sensor by Nissan) does is it tells the computer how warm the engine is. This allows the computer to decide on base fuelling - i.e., how rich or lean to set the base mixture. If it is not sending a signal at all or it's reading like the engine is very cold, the computer will go max rich and never guess that something's wrong. The computer also will not pay attention to the O2 sensor until the CTS tells it that the engine has reached a certain temperature. CTS/CHTS = base mixture setting O2 sensor = mixture adjustment, range limited MAF sensor = mixture adjustment, range limited

Is it that the air coming out isn't warm enough? Or is it that there's not much air coming out of the vents?

Check for a clogged catalytic converter or a dead coolant temperature sensor. Those won't set codes.

Coolant temperature sensor.

They're either 70s/80s factory optional "Rally" wheels from a GM truck or aftermarket reproductions of such. They're pretty oogly.

Yeah, I know - it's very strange. On the other hand, since that D44 that Dana supplied Nissan turned out to be such a failure, it's no wonder that every other truck maker in the world fled Dana in the last few years AND that Dana went bankrupt.

In that case, buy a Nismo Frontier, get a Stillen blower kit and the Stillen brake upgrade kit, be done with it. FYI, the rear end in that Titan is an honest to god Dana 44.

Yeah, you're going to want the V6. The I4 is an OK motor, in either of its incarnations but you can pretty much forget about making more power for it unless you find a KA-series four in a Pathy (good luck, most of them were Z-series and as GG said most US Pathfinders are V6s); then you can use some of the performance stuff off the 240SX. The 90-up V6, on the other hand, is pretty much the same engine as in the Maxima and the first of two generations of the 300ZX, so while the aftermarket isn't great, it's a lot better than the one for the four bangers. There are blower kits running around for the engine, for example.