idle fluctuates and car is running hotter than normal

[frankoman87]

When I first start my mustang, it idles just fine. When I start driving it, I noticed that when I come to a complete stop, my car is idleing very high for some reason. My tach doesn't work but I would guess it's idling around 1250-1500 rpms instead of the normal which I believe is around 600-750.

I'll shut the car off, then restart and it corrects the problem which I think is rather odd.

Also, while I'm driving, the car runs a little higher than the halfway point on the temp gauge which it has never done before. I'm guessin it runs at about 205 -215 degrees and I remember it running at about 185-190. Could this be a thermostat issue??? I can also smell antifreeze while driving the car. It's not a strong smell but I can smell it. The car is not leaking and I just had my radiator flushed. Could this be my heater core?? I heard they go bad on the fox body mustangs pretty regularly.

Any help would be appreciated. I'm getting a code reader this week so hopefully that will help me diagnose these problems by myself.

 

[Rerun]

The idle problem could be a couple of things. First I would inspect your IAC (Pendulum connected to the throttle body with a harness connected to it), clean it out and see if that helps. If that doesn't help, then I would next check for any vacuum leaks.

Smelling coolant and running hotter than normal suggests that you may have a head gasket leak. Check your oil dipstick for waterspots or milkshake looking oil. Most of the time the dipstick won't tell the story and you'll have to run some other tests. This is only a suggestion as it could be other things. Since you just had your radiator flushed, it may involve that. Did they change the thermostat when they flushed the raditor? Keep us posted.