97 Cobra overheating!

[amnat]

Hey, I'm new to these forums and I'm sorry in advance for asking a new question.

So I reinstalled the oil cooler after replacing the oil filter adapter gasket. Filled the cooling system as normal from the crossover tube. Tried to burp it but there are no bubles! The car will overheat while I'm burping it so I shut it off. Let it cool for about 30 mins and try again but its still the same result. Tried it about 3 times and still nothing, no bubbles, and it overheats.
I'm pretty sure the water pump is fine because the coolant will overflow out of the funnel if I touch the gas. I was thinking it might be a head gasket so I checked the oil and its the normal color, so is the coolant (green), there is no water coming out of the exhaust, and there is no misfire. So I'm pretty sure its not the head gasket. I'm thinking it may have been the thermostat so I grabbed all the hoses and they all felt very hot so I would think the thermostat is still good ( I'm really not sure if that is a proper way of testing lol).
Based off of that can anyone rule out any problems or possibly know what is wrong with it? I feel really dumb for not knowing this. If it makes a difference it has a vortech supercharger on it but idk if that would change anything.

Thanks for any info anyone might have.

 

[SNAKEYE]

Sounds to me like you've done nothing wrong but another gremlin has crept in. You may be having a problem with the fan motor, the fan power supply wiring, the CCMR, the ECT may have a problem. or a radiator hose may be collapsed.

Did the radiator fan run?

Can you spin the radiator fan by hand (without the engine running of course)?

Does the radiator fan run when you switch the A/C on?

Is the electrical connector on the fan motor clean inside, and mechanically and electrically sound? I had mine fry!

Unplug the ECT, start the engine, and jumper the ECT with a small wire, a paper clip will do. The radiator fan should start immediately.

Are the radiator hoses looking normal?

Testing the CCRM is beyond my expertise.

 

[amnat]

Hoses look OK, I'll check. The fan in a few mins, thank you.

 

[xblitzkriegx]

give this a try

http://www.svtperformance.com/forum...ine-coolant-radiator-burp-fill-procedure.html

 

[amnat]

I appreciate the help guys. Turns out list was the fan. You guys wouldn't happen to know when they should start spinning would you? I'm guessing around 1/4-1/3 of the way up the temperature gauge (it doesn't have a temperature readout lol)

 

[brucesvt]

have you tried the fan sensor? my 96 had the same problem this past summer and turned out it was the fan sensor got a new one and the car was up and running

 

[SNAKEYE]

I appreciate the help guys. Turns out list was the fan. You guys wouldn't happen to know when they should start spinning would you? I'm guessing around 1/4-1/3 of the way up the temperature gauge (it doesn't have a temperature readout lol)

With a stock ECT sensor my fan came on with the temperature gauge pointer just about through the "M", and the fan turned off just about through the "R".

Did you unplug the ECT sensor and jumper it to force the fan to turn on?

 

[SNAKEYE]

FYI, here's a curve and chart out of the 1997 Mustang service manual showing the relationship of coolant temperature to ECT resistance.

If you have an ohmmeter you can unplug the ECT and measure its resistance to see if it agrees with the ambient air temperature, which would approximate that of an engine left to cool overnight.
An "open" ECT would have infinite resistance indicating a temperature off the bottom of the scale.
A "shorted" ECT would have zero resistance indicating a temperature off the top of the scale.
A shorted or open ECT wire circuit would have the sane effect, so test the circuit for an open or short.

 

[amnat]

Im sorry i havent posted for a couple days, I forgot my password lol. Ok so I'm super confused again. Turns out the fan worked, I unplugged the temperature sensor on the passenger side of the crossover tube, jumped it with a paper clip and the fan turned on. So I replaced the temperature sensor but the fan still won't turn on. Weird thing is it will turn on if I unplug the sensor the fan turns on even if I don't jump it with a paper clip!!!!
Is that normal?
Also I did the boil test on both, they both have no continuity when cold or hot! But the sensor on the driver side has no continuity when cold but when it is hot it has continuity. I'm very confused! Does anyone know how these sensors work?

 

[SNAKEYE]

Im sorry i havent posted for a couple days, I forgot my password lol. Ok so I'm super confused again. Turns out the fan worked, I unplugged the temperature sensor on the passenger side of the crossover tube, jumped it with a paper clip and the fan turned on. So I replaced the temperature sensor but the fan still won't turn on. Weird thing is it will turn on if I unplug the sensor the fan turns on even if I don't jump it with a paper clip!!!!
Is that normal?
Also I did the boil test on both, they both have no continuity when cold or hot! But the sensor on the driver side has no continuity when cold but when it is hot it has continuity. I'm very confused! Does anyone know how these sensors work?

First things first: do you feel that you have successfully burped the cooling system? If there is no coolant in the crossover tube the ECT sensor in the crossover tube will not get up to proper temperature which will keep the fan from coming on.

Now then, the ECT sensor on the left front of the engine just operates the temperature gauge, so it is not in question.

Then, if jumpering the connector to the ECT sensor located on the crossover tube turned the fan on (which you say it did), the fan motor is okay (obviously) as well as the associated electrical connections, the CCRM, and the PCM.

Which brings us to the ECT sensor on the crossover tube itself. Here is how the ECT sensor works. If you look at the curve and temperature chart I posted earlier above you will see that the resistance of the ECT sensor varies inversely as to the temperature. That is to say that the lower the temperature (say 50*F) the higher the resistance (58,750 ohms) versus the higher the temperature (say 212*F) the lower the resistance (2,070 ohms). The electronics of the PCM understands these variations and tells the CCRM to turn the fan off or on as required.

As for the "weird thing" of the fan turning on when the ECT sensor is simply unplugged, this is a fail-safe feature that, should the sensor or wiring fail completely, the fan will turn on to prevent overheating.

I suggest that you revisit testing the resistance of the ECT sensor on the crossover tube. I know that they are hard to test because of the size and shape of the socket into which the wire connector plugs.

I suspect this ECT sensor is the problem.