ok weirdest thing. cars going fine, warms up, all of a sudden temp shoots all the way up to red hot. the second i fut the car in neutral, however, car goes instantly back to below the halfway point. then 1st, 2nd is fine... hit 3rd, engine temp shoot up to hot, instantly. radiators full, all fans are blowing, am i missing something really obvious?? because if the engines hot, shouldnt it STAY hot until the car gets turned off and chills for a minute?

 

1. check your radiator front and back and make shure there's no **** plugging it up.
2. bleed your cooling system. sometime air can get in there and build a pocket of ultra hot air so when it reaches ur temp sensor it'll read like it's super hot then read normal as soon *** the air bubble passes through. i did it the hard way. i replaced everything in the cooling system(t-stat, waterpump, radiator cap, flush and fill) before i figured out that my radiator was bad. 60.00 bucks for a thick aluminum one on ebay and i was set. that doesn't sound like ur problem though.

 

check your thermostat might be bad. Check hoses also.