94 Gt Running Extremely Cool

[SN95KnightMare]

I'm new to stangnet as a member but not to browsing the forums I've been trying to diagnose a cooling issue on my SN95 for a while with no luck. No matter how long I leave the car idle for it will not reach operating temperature. in 1 hours time it might reach operating temperature once with me reving it. At that time the gauges is in the middle but almost immediately the thermostat and fan kick on sending the gauge plummeting. now I've replaced all correlating sensors, thermostat, CCRM and coolant flush still no luck.

94 5.0 with only cold air intake and exhaust

 

[Stangbanger95]

Did you verify that the temp gauge is good? Throw a mechanical on and double check, any codes?

 

[OneWheelPeel]

Is the engine actually staying cold when this happens? Or does it heat up and the gauge just says its cold still? This could narrow things down a bit more.

 

[SN95KnightMare]

No lights so I figured no codes. the thermostat won't open up after idling for 45 mins. But if I get on it around town temp will go up thermostat will open and then engine temp plummets. Sometimes I go a whole 30 min drive to work with out hearing the thermostat open and cycle the fan on.

Cabin heat is working, so I don't have a clue.

 

[OneWheelPeel]

No lights so I figured no codes. the thermostat won't open up after idling for 45 mins. But if I get on it around town temp will go up thermostat will open and then engine temp plummets. Sometimes I go a whole 30 min drive to work with out hearing the thermostat open and cycle the fan on.

Cabin heat is working, so I don't have a clue.

If the heat is working then it means the engine is staying hot. I think your gauge is broken or a sensor isn't working... How are you verifying that the fans aren't running? I can't hear my fans running with my exhaust. I just can't imagine that the engine is really running that cold the whole time with out a missing thermostat.

 

[Stangbanger95]

Agreed. Of you have heat you have engine temp. Sensor issues.

 

[SN95KnightMare]

Brand new ccrm brand new ect brand new temp sending unit for the gauge new thermostat I've given her a pretty good once over and replaced a lot of 20+ year old sensors. And as for the fan when it kicks on I'm always at a idle and can hear it happen, because idling after getingredients on it or driving 20+ mins is the only time I hit temp and it's only for a second after the fan and thermostat do there cycle the gauge plummets.

 

[OneWheelPeel]

Brand new ccrm brand new ect brand new temp sending unit for the gauge new thermostat I've given her a pretty good once over and replaced a lot of 20+ year old sensors. And as for the fan when it kicks on I'm always at a idle and can hear it happen, because idling after getingredients on it or driving 20+ mins is the only time I hit temp and it's only for a second after the fan and thermostat do there cycle the gauge plummets.

Im thinking something is shorting out when the fans turn on and making the gauge not work properly. How fast does it drop? Instantly or slowly?

 

[OneWheelPeel]

Slowly as in a normal cool down.

 

[SN95KnightMare]

Not instantly, the car never ran like this until a year ago I've owed it since 2012. Dash lights surge a little when the cooling process begins but I figured it was just the alternator doing its job or the ignition coil needing a update. Could a faulty act sensor cause this issue. I just disregarded the act sensor thinking it wouldn't cause a problem like this.

 

[SN95KnightMare]

Fuel milage is garbage as well.