yesterday i was in a parking lot and my 2003 toyota camry xle wouldnt start the first time i cranked it, then i tried a second time and it started but the temperature gauge was almost in the red and all my indicators were on so I slowly drove it across the street to the Walmart auto section and talked to a mechanic. The mechanic said that it could be cause i did not have anything in the small plastic section for coolant/antifreeze so he put water in it and im having doubts about having water for coolant. [172,676 miles, 2nd owner.--Ed.]
OK, you have more to handle than some water in your coolant (although you will wind up R&R'ing w/ OEM coolant & distilled H2O). Do these 2 things first: 1/ If you think you have a leak, perform UV dye test (link, below), unless your coolant was painfully low d/t simple neglect. Drive around, keep a hawk-eye on Temp. Gauge and Coolant level. 2/ Thoroughly OBDII scan it. Pay a professional mechanic w/ Dealer-level Scan Tool to thoroughly OBDII scan it: incl. Mode-6 data, Live Scan, highway driving speed test; stored & current Fault Codes, red-yellow-green: the whole Enchilada. Otherwise, w/out your scanned Fault Codes-- you're just guessing in the dark. Post the Codes right here. LINK: How To Find Car Leaks With a UV Light
That's the least of your problems. What mileage. How many owners. Give us sufficient, minimal data & we can help.