what you might think is under body rust is probably just the undercoating with a film on it, or just a light coating of rust. Frame rot seems to be a big issue in the midwest and eastern states and not so much in the western and warm states. The chemicals they use for deicer is what kills cars, that is why California vehicles last for 50 years longer than an Ohio vehicle. I rarely hear about local vehicles having frame rot (old chevies don't count) but have seen a LOT of nasty pics from other states.

 

I just looked at pictures of frame rot, and I didn't see any of that today, so I guess it's a good thing.

I live in Canada, and they use rock salt for the roads, not so much the liquid deicer. But I went the last few years with my van and the rust was eating through the body, but not the frame.

 

not sure where in Canada you are, but I'm in Winnipeg, MB, and my GFs is really clean. mine, not so much, but still not too bad. Both are '93's. As for the oil gauge not working, its likely the oil pressure sending unit. They are pretty easy to change and relatively cheap

 

I'm next door in Ontario. Winters aren't as harsh here, but still pretty bad in the city.

 

Ontario uses quite a bit of salt. in canada we dont really need to worry about frame rot too much. its mostly just body rust. ie the wheel wells where the salt will sit