Jump to content

AC causing overheating


AZWSUCoug
 Share

Recommended Posts

I have a 2014 Ford Fusion Titanium.and yesterday while I was driving home yesterday my car started overheating. I was about 15 minutes into my commute home with the AC cranking (I live in Phoenix and it was 110 yesterday), when I noticed the acceleration was a little choppy and 10 seconds later I got an alert on my dash that the car was overheating and the heat sensor was all the way to the top. At the time I was on a long onramp with no shoulder to pull over to, so I just waited it out a bit. After driving a bit it occurred to me that maybe shutting off the AC might help, so I shut it off and sure enough the temp gauge started going down. I drove about 5 minutes without the AC and the temp gauge stayed at the normal level, so I decided to give the AC another try and after about a minute the temp started going up until the AC was shut off again. Finally, when I was off the freeway and I was in much slower traffic I gave the AC one more try and it too a little longer than the previous time but it started rising again, until the AC was shut off.

 

I got home, turned the car off and called the Ford dealership and they told me to just bring it in. On my way to the dealership I decided to try the AC again, to make sure the issue was replicable by the mechanics but this time the temp gauge stayed right in the middle. So, I turned around and headed home instead with no issue. This morning I commuted to work with the AC on, still no issue.

 

My question is, was this a one off thing or something that could potentially come back? My car is still under warranty for about 9k more miles, so if this issue could happen again, I would like to get it fixed under warranty. But if Ford can't replicate, I doubt there is much they can/will do.

Link to comment
Share on other sites

Sounds like the fans weren't working properly. The A/C dumps a lot of hot air near the radiator and if the fans aren't running it will overheat quickly. At this point all you can do is wait and see. But make sure your coolant is topped off.

 

If it happens again, stop the vehicle and see if both fans are running when the A/C is on.

Link to comment
Share on other sites

Usually, driving at highway speeds, fans are not even needed. The airflow through the radiator is greater than what the fans can provide. I don't even have a fan on my race car. It will overheat if I let it idle too long or going too slow but as soon as I get up above 30 to 40 mph, it starts cooling down.

 

I guess the design of the Fusion air intake for the radiator is such that fans are needed at speed but I find it unlikely.

Link to comment
Share on other sites

I thought about that but I couldn't come up with another explanation why it only overheats with the A/C on at speed. When the fan went out on my Edge it was in city traffic so I don't know how it would have behaved at highway speeds.

 

Maybe it's a combination of low coolant and fan failure.

Link to comment
Share on other sites

You haven't said if the car was actually overheating. The temp rising a minute after turning the A/C back on is awfully fast.

 

I would still have taken the car in for service. There's always the possibility they'll find something. Let them tell you they couldn't replicate the issue, instead of you deciding that, and get it documented on a service ticket. If there's an issue after your warranty expires, you at least have a bargaining chip

Edited by drolds1
Link to comment
Share on other sites

Street driven (not race track) factory equipped cars NEED all fans running when the AC is on, especailly at 110 degrees. The is a HUGE heat load added in front of the radiator to to cool the condensor coil.

 

The entire cooling system should be checked. It is not always true that the dealer needs to duplicate the problem. There are things they can check even if it is not acting up.

 

You experienced a problem so take it in.

Link to comment
Share on other sites

If you don't like my race car comparison, I can give you another situation where a street driven vehicle had no problem without an operational fan. I had a Ford Ranger in which the fan clutch failed (free wheeled). This was on the return of a long trip, towing my race car across the dessert. Most of it was on the Interstate but I noticed that when I came to a stop the coolant temperature would start rising. As soon as I got back up to speed the coolant temperature would go back to normal. I was also running my A/C because it was hot in the desert that day.

 

I did stop to see if I could figure out what was causing this. It didn't take long to find the fan was not being driven due to the failed fan clutch. I checked to make sure the fan was not going to come flying off and it seemed secure enough. I continued on and just made sure not to go too slow or stop for an extended period without shutting the engine down. I made it home just fine. I even drove it back and forth to work through the week until I got a new fan clutch and time to install it.

 

That doesn't mean all vehicles can run with no fan(s) without overheating but they should still be able to run at highway speeds without overheating unless they have a sideways mounted radiator like the old Mini Coopers did. It for sure sounds like the OP's car has something wrong with the cooling system. Maybe the thermostat is malfunctioning and not opening all the way but you are right, the entire cooling system needs to be checked out (including the fans).

Edited by Monochrome11
Link to comment
Share on other sites

The issue started happening again on Thursday, so I set up an appointment to take it it this morning. They took a look and found that there was an issue with some valves in the front of the car. But here's the kicker, since the valves were damaged in what appears to be cause by an accident, they are not covered by the car's warranty. I bought this car used in December and the Carfax report listed no accidents for this car but apparently there was one and must not have been reported. The dealership I bought this from is not the same one I took it in for maintenance (it was a Fiat dealership). Is there anything that can be done to get reimburse for a car they said had no accidents, that has infact been in an accident?

Link to comment
Share on other sites

You could try complaining to the dealer but they'll probably just tell you that they trusted the Carfax as well. Check Carfax again, as there are cases of accident reports showing up later. You could also try complaining to Carfax but I doubt you'll get anywhere as they have a loophole. They can only relay information that's reported to them, and not all information is. See this.

 

Carfax is only a shopping tool. It's still important to have a potential purchase thoroughly examined by a competent technician.

 

BTW, what valves were were causing the problem?

Link to comment
Share on other sites

I assume it's the active grille shutters, which explains why the airflow from highway speeds weren't enough to keep it cool - no air was getting in.

There seems to be some question of which Fusions have them. I thought those closed at highway speeds anyway. It's my understanding that the shutters are electrically activated using stepper motors. Therefore, I'm not sure that "valves" have any involvement with active grille shutters. I got this from a GM press release:

 

 

The air shutter system uses sensors to feel and sense wind and temperature conditions. The sensors are married to electric motors that open and close the shutters automatically. With the shutters closed at high speeds, wind drag is reduced. At lower speeds, the shutters open to maximize engine-cooling air flow. The air shutter system contributes nearly half a mile per gallon in combined city and highway driving.

 

 

I guess we'll have to see if we get a more detailed explanation from the OP.

Link to comment
Share on other sites

I assume it's the active grille shutters, which explains why the airflow from highway speeds weren't enough to keep it cool - no air was getting in.

 

If the active grill shutters were stuck closed, the A/C wouldn't be blowing cold air.

Link to comment
Share on other sites

  • 2 weeks later...

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

 Share

×
×
  • Create New...