hey guys, my car starts to overheat after about a month of driving. I refill it with coolant and it drives alright. I tested for a coolant leak, the mechanics said there was none, and the coolant system maintained good pressure. but this time, i put coolant in, and the temp never went down? could it be my theremostat, cause anyway, i was thinkin, i shouldn't have to change my coolant every month! any help will be appreciated.

Thanks

the thermostat could be clogged with trash, or just old and stuck closed and not letting enough water thru.

Are you saying that you're loosing coolant? A faulty thermostat will not cause coolant loss.