I have a 1995 Toyota Corolla and last night while driving on the freeway, every time I pressed the gas pedal, the car would make a very noticeable sound. I pulled over and, as soon as I did, steam started coming from under the hood. After opening the hood it appeared the steam was coming from the radiator cap. Unfortunately I forgot to check the temperature gauge on my dashboard.
I had the car towed and, after inspecting it today, there appears to be a white residue around the radiator cap and on the radiator. I checked my oil, which was about halfway between the full and low mark, and it appeared to be clean. My coolant is also halfway between full and low, but I am not sure what it was before this happened. I did not notice this earlier, but my car looks like it is leaking some sort of fluid onto the street, possibly before this all happening.
I will probably end up taking it to a mechanic, but I was wondering if you could shed some light on what it could possibly be so I am not going in uninformed. If you need any more info, please let me know and I will try to deliver. Thanks guys!
Edit: here is a pic of my radiator cap. I am assuming this is a problem. Note, the metal part in my hand simply came of like this, I didn't force it off or anything.