Anyway, I have a Grand Am 2003 V6. It only has 80k miles. My car ran great when I got it(used), but at some point it began to have minor temperature problems. It would always run a little bit hotter than it should. This basically just meant I couldn't keep it idling forever. At some point I took a drive for about an hour and the vehicle was running fine. I got to where I needed. On my way back home though it overheated. It didn't blow up or anything because I caught it in time, but it hit the redline. I checked it and it had no coolant at all. I let it cool off and filled it up with water and there weren't any leaks and it drove fine after that except for the before mentioned idle-overheating problem. This was about 2 years ago.

I ran over a deer a few months ago though and now the problems are worse. It was discovered that one of my fans was burned up, so that could have been the previous problem. Now though, the radiator has been replaced and both fans work and now it stays hotter than usual just driving. The temperature it usually should be at is about 200F. It now commonly stays about 205 and can get as high as 225 with just normal driving(note, 260F is red line)

One more unique thing about this. If my engine is at about 205 when I park, if I turn off my car and leave it for about 15 minutes, when I come back and start it, it will usually be about 215 or so. Basically, noticeably hotter after turning it off and back on.

I've checked for leaks -- There may be a very small leak somewhere. But it shouldn't be anything to worry about because I fill it up with about 2 cups of coolant or so after 3 or 4 months. So it's a small leak, if not just evaporation. And of course, I've checked to make sure I have enough coolant and that it's mixed properly.

And the only other thing(which is getting fixed soon) is that my air conditioner lines are ran wrong with one of the lines right against a heat shield on the engine, but that shouldn't affect the temp of the car should it?

So what could be the problem? I don't expect to fix this myself, but I'd love to be able to suggest to a mechanic maybe what the problem is instead of them tinkering around for a couple of very expensive hours.

Edit: I don't know how I forgot to mention this, but there is a hissing coming from my engine. I thought it was from my A/C(which is normal?), but I'm beginning to think it's not. Basically, I can hear a hissing that appears to be coming from within the air vents in the interior. The hissing is particularly loud when idle or braking and goes away completely while doing hard acceleration with it getting more and more quiet with the harder I press the accelerator.