Overheating problem, temp gauge all over the place Options

[Mycurse180]

My car has never had a temperature problem, always right in the middle of the gauge.

Today on my way to class, I noticed the temp went all the way up. Naturally i shut the car off and pulled over.

I decided to drive it back home since I wasn't far. I got home, checked the coolant level and THERE WAS NONE. Good job previous owner.

I filled it with coolant and expected it to be fine. Took it for a test drive and the temperate randomly fluctuates between really hot and normal.
It will climb high and then drop back down to normal very quickly and it repeats the process. I asked a guy I knew and he said maybe you have air in the system and to run it without the radiator cap for a while.

Anyone have any input? Appreciate it!!

[TRD_Ian]

dont blame the previous owner lol thats your own responsibility to check!. how many miles are on your car? id start worrying why you all of a sudden had no coolant, IE checking for leaks..if you had toyota coolant in it start looking for pinkish/red crusty residue for your problem prolly around your water pump area..when you go to "burp"the system make sure you have the proper mix ratio of water and coolant, watch your temp gauge and like manny said turn your heat up all the way and select the air to face for your blower that way its pushing the most air. fill up the rad and the res and start the car and just carefully watch its gonna bubble a bunch and wait for your thermo stat to open up u can tell this by your lower rad house i believe when it gets hot and you should also be able to see a bit of a swirl in the coolant once it opens up. i usualy speed up the process by reving the motor from the engine bay up around 3 grand to help it heat up. whole process should take about half an hr. but like i said id start looking in to why you had no coolant see when your timing belt and water pump were done last and checking for that coolant residue