Hello,

I recently acquired a 93 Formula with a coolant leak issue.

The oil filter cooler housing was leaking, I repaired that and began to fill with coolant, noticed I had a leak from the Low Coolant level sensor and I replaced the o-rings since the sensor itself is discontinued.

No more leaking thankfully but now that I try to bleed out the cooling system it overheats, I noticed the thermostat didn't seem like it was opening so I replaced that, and continued. The cooling fans did not kick on, but I have access to a scan tool and did a functional test where they came on and work with no problems. I ran the car and checked temps. The dash reads where I believe it really is, but the scan tool was reading roughly 40 degrees off, so I replaced my temperature sensor and its now only 20 degrees off, but still the fans do not kick on.

Any suggestions??? Also on another note I have some heatercore problems as the steam is coming out of the vents inside the car and the heat and blower is all off....

I really want to get this car fixed soon so I can have everything ready by springtime! I live in NY so its still cold and crappy here so no need to drive it yet, but I dont want to wait once its nice out.

 

From what I understood the wiring and the fan motor is fine, the temp. sensor is new so that's not the issue. That means that there's a problem with the computer. I'm not familiar with f-body computers yet so forgive me if I'm wrong but the temperature at which the fans automatically kicks in must be set too high or not set at all, or there's a problem with the link between the sensor and the fan on the chip.


As far as the smoke issue goes, inspect the heater core for leaks and the vents for moisture. What does the smoke smell like? If it's sweet it could be a coolant leak, if not it might be moisture getting inside the vents, also check if the microfilter isn't wet.


Good luck and let us know what you find

 

Which temp sensor was replaced? What actual temps were indicated by the scanner?

Cooling system info

 

The smoke is sweet so its probably a coolant leak in the Heater core, or its just bad.

The sensor I replaced was the Temp sensor on the front side of the motor just under the intake.

I replaced the sensor because originally the dash would indicate maybe 250 and the scan tool would read 208. I was under the impression the sensor on the front was for the computer and the sensor on the drivers side was for the gauge. After the sensor was replaced it now reads 223 was the highest I let it go. I think its better, but still not triggering the fans to kick on... I thought of wiring the fans to a separate switch, but I'd prefer things to be as they were supposed to be.

 

You probably don't have a problem. Stock fans aren't set to come on until the PCM sees 227 degrees (low speed) and 235 degrees (high speed). LT1s were designed to run hot.

You're in NY and it's cold out. Your car simply isn't asking for the fans to come on yet.

 

You obviously didn't read the info in the link I provided about the cooling system/fan operation.

 

shbox - I read your link, and its very useful. I replaced the sensor in the water pump because the vehicle was indeed overheating and was barely in the red zone so I believe the gauge sensor to be accurate. The sensor in the water pump seems to be off when comparing to the gauge sensor, and its brand new. I will try resetting the PCM and see where that gets me. If still same problem I will check the ohms of both sensors and see if they are correct. I will also try turning the AC on while doing the bleed out.

 

I had the same problem with the last Trans Am I had and I simply ran them on their own switch. I understand you dont really want to do that but it is probably going to be your simplest fix. As far as lt1's running hot both of mine have ran right around 185 almost regardless of what Im doing to them(both were stock) that is why i personally ran a switch especially with aluminum heads I tend to get nervous around high temps