Over Heating Problem

[shadetree101]

Need help!! On my 2000 Malibu I have Replaced my Thermostat and Coolant Temp Sensor. Fans do not come on when at temp. Fans only come on when AC is on. There is 5VDC on connector to coolant Temp Sensor. There is also no Check Engine Light noting any problems. Coolant Boils out of Resivor because Fans do not cool coolant. any suggestions would be appreciated.
Shadetree101

[wymi]

Sounds like it might be an ECU/BCM issue?

[shadetree101]

Thanks for the hint. I was afraid that might be the case. Before I invest in a new one or a reflash. I will try to Ohm out the wire and then try to clean and reseat the ECU.
Thanks for the reply
shadetree101

[bcopeland]

1) how many miles on that orange anti-freeze?
2) Are you losing any coolant? Look by your thermostat under the exhaust manifold elbow and see if there is any anti-freeze sitting there.

[shadetree101]

Thanks for the reply bcopeland;
As far as the red stuff I stoped using that about a year or more ago. I saw the gunk it was leaving and went to the all putpose green, after fushing the system out. As far as a coolant leak around the intake Manifold there is none. As soon as I can I will try to short the Sensor wires with a 150 Ohm resistor and see if the fans come on, then go from there.
Thanks again.

[tractorboy]

you might also want to get the car scanned, the temps that the fans come on can be set in the PCM, sounds like yours might be set too high. On my Impala they were set to come on at 230 F . I set them to both come on at 180. Since the fans are coming on with the AC I do not think it is a relay or anything like that.

[wymi]

Originally Posted by tractorboy

you might also want to get the car scanned, the temps that the fans come on can be set in the PCM, sounds like yours might be set too high. On my Impala they were set to come on at 230 F . I set them to both come on at 180. Since the fans are coming on with the AC I do not think it is a relay or anything like that.

Could you tell us how you set the fans to come on at a lower temperature?

[tractorboy]

you need a tech2 scan tool or a device called a power tuner. I have the power tuner. It is software that runs on a laptop and through a cable that hooks to the ALDL talks to the car computer using the OBDII gateway.

[wymi]

Originally Posted by tractorboy

you need a tech2 scan tool or a device called a power tuner. I have the power tuner. It is software that runs on a laptop and through a cable that hooks to the ALDL talks to the car computer using the OBDII gateway.

Thanks, where can I purchase this software and whats the cost?

[tractorboy]

At first the it seems expensive, I look at it as an investment. I was experiencing alot of pinging, which overheats the engine, and damages the engine. After taking out some timing and adjusting my fueling I have more HP and an getting 25 - 27 mpg with an LA1 Impala. My case was extreme, the Chevy dealer was not doing anything. I had to do something. I am glad i got it.There are several , there is DHP Digital Horse Power , tHERE IS SUPER CHIPS PREDATOR, and after carefull consideration the one I finally chose, HP Tuners. they have the standard and inhanced . The inhanced you can use a wideband 02 + other stuff, the inhanced has data logging , the standard you will need a notebook with usb v2, the inhanced you can use a notebook too if you want
http://www.hptuners.com/