Hello! I'm new here -- just bought a '97 Quest last week. I was living in a car before, now I've got this minivan to make life a bit more comfortable, and eventually I'd like to upgrade to a short school bus. For now, I want to make sure things are running reliably, and I'm willing to invest a bit of money to help it last a long time it's got about 180,000 miles on it, it has some damage on the passenger side doors from a collision which didn't seem to warp the frame/chassis or anything. All the electronics and everything on the inside works great, for the most part it's in decent shape -- for $800 I'm not complaining.

The minivan does have a few issues that I wanted to ask y'all about.

1) Something makes a raspy, grating noise when I accelerate. It's only when I push the gas pedal down a certain amount. It doesn't seem to matter what gear I'm in. Mostly, it happens when I'm climbing a hill. I made a video while driving uphill -- I know there's a lot of road noise too, but you can hear the difference when I let off the accelerator a couple times: https://www.youtube.com/watch?v=gWERq3a9FCE
It sounds pretty scary, I really have no idea what it is.

2) The whole car wobbles at speeds above 55 MPH. It could just be unbalanced tires, I might have them balanced, but before I spend $16/tire I thought I'd check if this is a common problem -- I read somewhere that there can actually be an issue with the rear brakes that causes a vibration that feels like it's coming from the front? Or, maybe it's related to problem 3 or 4...

3) It seems like something is loose in my suspension/steering. When I go over speed bumps or similar, there's a clunking sound especially from the left front. The direction of travel is not very consistent -- for example, if I have it in cruise control and I'm climbing a hill, when it downshifts into a lower gear to get more power it pulls to the right and I have to correct the wheel to the left; when it shifts up again, I have to correct to the right. When I'm taking a curve on the highway (I think it's only when turning right), there's sometimes a point where something shifts and suddenly I am turning more sharply to the right even though I didn't move the wheel. I had the car looked over by a mechanic when I first got it and he noticed that my left front ball joint was broken, I replaced it and got an alignment but this is still happening.

4) My parking brake light is on permanently. Is it likely a broken sensor, or is it possible the brake is still applied a little bit? The action of applying and releasing the brake seems to be normal, and I don't notice excessive drag, but maybe it's dragging a little bit and contributing to the wobble or steering issues?

And finally, this isn't a specific question, but is there anything you recommend I do as preventative maintenance? The mechanic said there was a drip from the main seal, between the transmission/engine; is that a big deal?

Thanks so much for any help you can give me

Wobbling may simply mean a defective tire. Been there done that. Inspect tires for any signs of warped walls, it happens. And inspect rotors while you are at it.

Thanks! My tires seem in pretty good condition overall, but I'll check the walls more closely.

Something to add -- my front wheels get hot when I drive, significantly hotter than the rear wheels. The parking brake should only act on the rear wheels, right? So it's probably not from problem #4 (actually, it looks like low brake fluid can cause this light to stay on, and I know it is low -- the pads are getting thin -- so maybe that's it).
Maybe I have a problem with the brake lines or master cylinder or something, not releasing the disk brakes all the way.

Dragging brake calipers would cause overheating. Check to see if pins are seized. I can't recall if 97 Nissans used twist in pistons, those get seized sometimes too.