CaliJoe

Hey folks -

I'm a new mustang owner and have been doing some work on the car, but I'm trying to narrow it down.

I have a 04 GT w/ BBK headers, x-pipes, hi-flo cats, flomasters and bbk air intake.

So here's the issue. I've been getting some overheating. At first it was my CCRM, so when I replaced it things worked well for a bit. My AC is blowing cold, etc. and my cooling fans kick in as soon as it's turned on.

But here's the symptoms: AC will be blowing cold, and all of a sudden after driving for a while, it will start blowing hot. Shortly after I see the temperature starting to rise. I check the fans, and sure enough, they are not spinning.

If I let the car cool overnight, the next morning my AC will be back cold, fans spinning etc, until driving the car for a good while and it happens again.

I will greatly appreciate any help! Thanks

CaliJoe

Also one more thing I forgot, once the AC starts blowing hot, if I leave it on, the RPMS on the car when idling will start going down like it's going to stall. Again, thanks for any suggestions.

GT210

Have you checked your thermostat or coolant temp sensor.

CaliJoe

I'm actually about to change the thermostat, but I don't really know how to test it. I just figured it's cheap enough where I don't mind changing it out.

Haven't really looked at the coolant temp sensor.

Do the symptoms sound like it could be these two items?

THanks.

Sonic Mustang

Put in in water.

Heat the water.

Use a cooking thermometer or laser thermometer to see when or if it opens.

CaliJoe

Even typing this sounds lame, but can someone point me in the general direction of where the coolant temp sensor is? Thanks.

GT210

yes its right on the front of the intake if your standing in front of your car hood open looking at the motor find the alternator and then look to the left there should be a silver or aluminum coolant tube on the front of your intake manifold and to the left of the alternator is a sensor on the top of the cooling tube cant miss it.

GT210

Basically what your thermostat sits in follow that tube to the left and you'll find the sensor its the only one on there cant miss it.

CaliJoe

Ok, thanks got it. I changed out the thermostat (even though I tested the old one and it seemed to be working fine).

I'm on my way to pepboys to buy a new coolant temp sensor.

Based on the symptoms, any other culprits I should be looking at?

Thanks for all the quick help. This is the perfect place for a "forum / youtube" mechanic LOL.

GT210

Low refrigerant levels will cause too much superheat and cause the compressor to get too hot . burnt refrigerant turns acidic and can ruin internal compressor parts as the refrigerant cools the compressor. So check your levels they may be getting low.