Electric fan comes on too early
05-08-2010, 11:23 PM
#1
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Thread Starter
Electric fan comes on too early I have install an electric fan on a 2002 5.3 vortec that i swap into my 55GMC truck, used HPT to turn fan on at 200 degres but the fan comes on early before the thermostat is even open. The scanner shows the temp at 200 but the temp gauge is only at 180 and the lower rad hose is still cold which tell me the thermostat is not open yet. I have check the engine temp with a laser temp gauge and its at about 175 when the fan comes on. Any advices? Thanks
05-09-2010, 09:06 AM
#4
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Thread Starter
05-09-2010, 11:23 AM
#5
TECH Resident
Turn the fans on later.
The temp in the head is usually the hottest point. Is your gauge sensor in the head as well? I have seen aftermarket gauges read way off from the factory sensor.
The temp in the head is usually the hottest point. Is your gauge sensor in the head as well? I have seen aftermarket gauges read way off from the factory sensor.
05-09-2010, 07:02 PM
#7
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Thread Starter
Yes I'm using the pcm to control the fan on and off. The fan actually comes on when the pcm tells it to come on at 200 but i don't think the engine is at 200 degrees at all. Like i said the coolant is not circulating thru the thermostat yet when the fan comes on. I will pull the thermostat off to see what degree it is and see if there something wrong with it. I was thinking to go with an aftermarket controller with sensor if i can't figure out this issue.
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05-09-2010, 07:48 PM
#8
Odd........sounds like a 200 degree stat. The temp sensor in the head is commanding a fan on through the PCM. Kinda wierd the temp gun says it's cooler. Did you shoot the temp with the IR right by the stock temp sensor?
Could you post the tune file......?
T,
Could you post the tune file......?
T,
05-09-2010, 09:40 PM
#10
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Thread Starter
Pulled the thermostat off today and it a factory stat 187 degrees. It brand new but i will test it in water sometime this week to make sure it open at the right temp. Yes the IR was right at the sensor and the temp was around 175 when the fan came on so i look at the scanner reading it was showing 200 so the fan came on. I'm sure all the air is out, i loosen the front steam line and had coolant come out. I will see if my programmer can print the tune file.
05-09-2010, 10:12 PM
#11
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I'll see if i can print it out for you.
I still have my doubts of the accuracy of the gauges and the IR Gun you have.
Both the gun, sensors, thermostat and gauges all have manufacture tolerances some are upwards of 5%
I still have my doubts of the accuracy of the gauges and the IR Gun you have.
Both the gun, sensors, thermostat and gauges all have manufacture tolerances some are upwards of 5%
05-10-2010, 07:04 AM
#12
Pulled the thermostat off today and it a factory stat 187 degrees. It brand new but i will test it in water sometime this week to make sure it open at the right temp. Yes the IR was right at the sensor and the temp was around 175 when the fan came on so i look at the scanner reading it was showing 200 so the fan came on. I'm sure all the air is out, i loosen the front steam line and had coolant come out. I will see if my programmer can print the tune file.
T,
05-10-2010, 08:38 AM
#13
Teching In
Thread Starter
If you could just post the file here, printing it will not do much good, unless you print a couple of screens that need to be looked at. Assuming this is HP Tuners, several of us on here can look at it for you. Not to say your tuner doesn't know his business, but extra eyes always help. If you've never seen one, tune files are very tedious, and have an enormous amount of info to look at.
T,
T,
05-10-2010, 10:28 AM
#14
Look at the bottom of the page, when you hit reply, there is a button there that says manage attachments. There are several types of files you can attach. The one that has "hpt" is an HP Tuners file format, so the site will recognize it. Once you hit manage attach. a new window will open to find the file on your PC. Navigate to where you saved the file, and attach. Don't worry if your PC doesn't recognize the file, the site will....and so will we....
T,
T,
