I have a 2007 Ford Edge, it has ~180,000 miles on it. The car was running great, the last couple years the heater has been on the fritz in the severely cold days, but was still pumping out enough heat for me to put off an inevitably expensive repair. I finally took it into a Firestone, they said that the heater was fine, they did a flush on the radiator to make sure it wasn't involved and sent me on my way for $400...I wasn't too happy, because it was still not working at 100% during the last cold days this spring. Then this summer overheated. I got it home after I let it cool with the heater blasted on a 90 degree day, but it got home with a couple stops to let it cool before it got all the way to the red at all. I did my research and found the most probably causes (from what I could find) were either the thermostat
: I changed this since it was only a very cheap and easy part to replace, this did not improve the overheating issue. I then found it may be either the A/C or the water pump
as the most likely culprits. I knew I couldn't do my water pump living in an apartment with limited space, time and tools and same with the A/C if it was anything beyond using a kit can to recharge it, and I know that you might damage the system more with those if it is under certain conditions. I did more research though to try and narrow it down for the garage and my mind (so I wouldn't get too ripped off), I found that the water pump would be causing it to overheat at idle, more than at speed. The car however, would begin to overheat much more often at high speeds rather than at idle. I then looked at A/C, if I ran the car with no A/C or fans it would rarely begin to overheat, this lead me to believe it was A/C related most likely. I opted to take it into the garage, when I got there I told them what was happening, they said they think it might be the thermostat right off the bat, I told them I had already changed it, I said I thought it was probably the pump or the A/C. They took it for the night and said they would look into it. I won't get into the how or why, as this is a debate on how to get this fixed rather than shop ethics...but they rebuilt my transmission
and changed the thermostat I already had changed and claimed it was fixed. As I am sure you can guess my naive self didn't get far before the car overheated again. I took it back to the garage and they ran more tests eventually finding that my lowspeed/idle fan was not working. They accredited it to either a bad assembly or a bad PCM. They investigated to find it was the fan not the computer and replaced that claiming to fix the problem. (Here is question 1: In your professional opinion, if that was the case, would I or would I not have found that specific problem during my testing of water pump failure...during this time I tried to get the car to overheat in Idle which happened only rarely vs much more frequently at highway speeds (like I mentioned with A/C on vs with it off) would the fan not have caused it to overheat during those tests at idle if it was the original problem?) The car however still overheated again today. I am now just wondering what someone else might think it is besides that garage, and I would love a professional opinion...if you can give one on what it might be causing my heater to not work and my A/C to cause overheating of the entire car? And also if indeed a failed fan would manifest itself as overheating a car during idle vs high speeds? Thanks so much!