AWD Problem??? Maybe, Maybe not??

[crashnburn]

Hi everyone, I just took a test drive in a 01 QX4 and loved it. This would be my first 4x4\AWD vechile and I wanted to ask ... . is it normal when you turn off the QX4 (while its in AWD) for it to jump forward?? Best thing I can compare it to is when you are starting a manual trans car and its in gear without you pressing in the clutch. Is this normal for the QX4 or can it be a sign of an issue?

Thanks for any feed back,

[KoukiS14]

Welcome to NICO!! Mine will do it sometimes if it's in Auto, ALWAYS if in 4wd. The conditions it seems to do it in while in Auto are if the system had been active at all during the drive (i.e. I lost rear traction and it sent power to the front). In normal 4wd, it's always 50/50.

Basically, the vehicle is releasing some strain on the drive train. It's my understanding that pretty much all 4wd vehicles will lurch a bit -- we actually just covered this not too long ago.

With that said, and even though the owner's manual suggests you can use it ANYTIME, I only use Auto in rain or mixed driving (snow / dry roads / ice), and 4wd when it's slick 100% of the time (mud / snow). I still feel Auto is a real nice setting, because you can actually make a u-turn while it's engaged.

[crashnburn]

Thanks for your reply and explaining how it works. Being new to 4x4\AWD I have never experianced anything like that before so only thing that came across my mind was lol Thanks again. Now I need to go back and pick her up so I can be a real member of the forum

[KoukiS14]

Welcome aboard!! Take some pics for us.

[02QX4ME]

My 02 QX4 does the same in "Auto". However, I don't feel the car jumps forward. I feel a shock and hear a loud sound like "bong" right at the moment I turn off. The sound is a bit uncomfortable to hear but I have got used to it. Only a few times it does the same as in "2WD", no shock no sound.

I know very little about AWD, 4WD, etc., but since day one I assumed it is the way those mechanical parts work.

[KoukiS14]

Actually mine doesn't really lurch forward either, but of course I'm always stopped / in park / e-brake on, so there's not really an opportunity for it to do so.

It does the clunk thing.

[SnowSurfLax]

Kouki - It is actually ok to run the AWD mode on dry pavement as it will only engage if the rear wheels slip and should disengage when they stop slipping.

If i understand the system correctly, it's actually not a true "AWD" system as it will only apply up to 50% of the normal power to the front wheels when in the AWD mode. So it only applies power to the front wheels if the brain is telling it to for that particular moment and even then only as much as power as it feels is necessary.

Anyone feel free to correct me if I'm wrong, but I think I read the specs right on it.

[KoukiS14]

Oh I know, at least according to my documentation, I can run it on dry pavement -- I just opt not to. It def. has a component that runs, even at idle and I figure I can minimize wear and tear on it.

Yeah it doesn't roll around with the front wheel engaged at all. It's actually just an implementation of Nissan's Attessa ET-S. With that said, it's a better system than a lot of other systems marketed as AWD that run via viscous coupling. I enjoy smashing the throttle in the rain and feeling the front dig in and pick up. . sometimes you can get a sweet 4wd slide if you hit a corner right.

I also enjoy lift oversteer, then correcting by adding a bit of throttle such that all four wheels are powered. It adds a new dynamic. . I think my next vehicle will have to be a G35x

[SnowSurfLax]

Damn, I gotta try that. Next time it rains here, which should be uhh...

Well, Feb if I'm lucky. Hopefully I'll remember that and find a corner without other drivers around me.