I've had my 4x4 Xterra for a couple of weeks and have noticed something I didn't on my 4x2 Xterra. When I accelerate... up around 3000 rpms, it sounds like the engine is working hard to get up to speed. Is this normal because of the extra weight on the 4x4? I never heard this type of noise on my 4x2 Xterra. It's almost like it is straining to get there.

i notice the same thing between the 2 models but i always thought it was the weight- there is something like 300 pounds more on the 4wd. quite a bit of weight, plus the additional drivetrain resistance.
i think its normal.

Note: There is only extra drivetrain resistance when the hubs are locked.

My engine grunts louder too at that speed. It lasts from about 3000-3500 RPM then it quiets down again. I figured it had soemthing to do with intake. exhaust, or harmonic balance, but if it's a 4WD thing, then I have no idea. I wouldn't think the extra weight would cause that but perhaps different routing of the exhaust (is it different???) could cause frequency changes. Beats me!

Same issue here. Between 3k and 3.5k in 3rd gear going uphill. Chuck do you get it going up Sahalie Rd?

Just some hesitation like the cylinders or injection isn't in synch. Then I just throttle through it and it goes away.

i have never noticed any weird sounds or noises- just that the engine has to work harder to do the same thing (sorry for the confusion there)- its not as 'peppy' in most driving situations, then again, you dont have 4wd either. there is enough difference to justify different shocks (and torsion bars?) and its enough weight for the ride height of the 4wd to be slightly lower than the 2wd.

i guess it would be the same as if you had a couple buds in the truck, but i've never noticed the truck labor with 2 people in it.

I don't get a hesitation...just a different sound like the engine is working harder. It'a louder and seems like it vibrates more. I get it in all gears and it doesn't matter whether or not I'm going up hills. I've gotten use to it and don't think much about it anymore unless someone else mentions it. I'm sure it's just an exhaust or intake issue.

If you're getting a hesitation have you tried running some fuel system cleaner?

Yup, same here. At about 2800 to 3000 rpm, I experience a noticeable change in noise and increase in vibration. It goes away over when I get a little over 3000. I figured it was an exhaust problem and unique to my X. Glad to hear other people are experiencing the same thing with no problems.

This may sound pretty out there, but it's an idea. Assuming that you're driving an automatic, in a modern/tiptronic transmission, the next gear will start spooling up which would make for a slightly increased noise. However, this is nothing that should really be noticeable. I am also assuming that if you're at 3500rpms then you're working it a bit above an average take off therefore making the trans hold on to the next gear slightly longer...
Like I said...it's pretty out there.

my 2001 did that for a while around the 2800-3500 rpm area...took it to the dealer and they said a part needed to be replaced...they ordered it in and after that it was all good...

i "think" i still hear it once in a while...i usually have my radio on or windows shut during the winter...sometimes i'll hear it over the radio and i'll turn it down but not hear anything anymore.

i just ignore it basically...i don't care about this truck anymore...its not mine (already sold it back to the dealer). my supercharged '02 will be ready on the 20th.

Do you know which part they replaced on your X?

can't remember off hand...i'll check in for you...