I am currently looking at a 1990 Nissan 240sx xe coupe with 102,000 miles on it with a five speed. Interior is in perfect shape. The engine has a rod knocking, but the largest problem is the rust. There is rust around the fenders and bottoms of the car (least of my worries). But there is rust in the engine bay around where the struts bolt in, and in a few spots on the frame. Now I understand that if these rust through and break the car is finished. The car drives well and the knock isnt too bad, but I'm worried about the rust. Can the rust be stopped for one? What would you pay for this vehicle? (central new york area). and should I just go try and find another 240sx. I will spend $1500 max on a car that will last me. As of now I'd say that I'd pay $1000 for this particular car. This is a tough choice, please help me out here.

 

It's hard to tell without pictures. Personally I would pick it up if it was under $800. I got my 240 with a toast engine & body damage for $350.
Frame damage can be easily repaired. Strut tower damage is a different story. If you can get a pic of it. We can hel you out more.

 

I have no idea about the rust, since we rarelt see that here(Southern cali)

As for the price of the car...700-900

 

check the base of the front strut towers where they meet the frame rails. Its right where the brake lines pass into the wheel wells. Press in hard all along them (might want to wear a rubber glove). If its rotted you may want to reconsider. It will stress fracture and ruin the alignment. Although $1500 isnt so bad a price for 100k