21-07-2013, 05:21 PM
Im sure most GTi owners hate this time of year due to the chronically hot engine temperatures. Ive never seen one cook its self because of this (except when the engine fans have failed) but i know a lot of owners unplug the brown coolant sensor so that the fans default to high speed. Issues with this can be over cooling (which can do just as much damage as over heating!) and premature wear on the fans not to mention that god awful noise all the time!
So, simple solution. Lower the kick in temp. On the gti, low speed comes in at 87 and high speed at 97 i believe. With this simple mod, you can set (to an extent) where the high speed fan kicks in
Locate the brown coolant temperature plug. Its located on the theromstat housing (right hand side of the block) between the green and blue sensors. There are two yellow wires running into this and we need to find out which the supply is. Grab a multimeter and find which wire has voltage running down it (should be about 4.5-5v).
Once you have found the wire, cut it and extend the wires to where you want the switch (no need to have it in the cabin really. Once its set, you may as well leave it) and solder a variable resistor on the end of the wires.
Next, mount your switch, tidy everything up and make sure you heatshrink all your wires to protect from water ingress.
Now its time to set it up. I suggest running the car upto the temp you want the fan to kick in (mines at about 95 degrees) and turn the knob (giggidy) slowly until the fan kicks in. Take it for a drive to try and drop the temp back down to normal driving temp and make sure the fans turn off. Normally they will turn off at about 7-10 degrees lower than kick in point so make sure you dont set it too low that it cant drop the temperature down low enough to switch them off
So, simple solution. Lower the kick in temp. On the gti, low speed comes in at 87 and high speed at 97 i believe. With this simple mod, you can set (to an extent) where the high speed fan kicks in
Locate the brown coolant temperature plug. Its located on the theromstat housing (right hand side of the block) between the green and blue sensors. There are two yellow wires running into this and we need to find out which the supply is. Grab a multimeter and find which wire has voltage running down it (should be about 4.5-5v).
Once you have found the wire, cut it and extend the wires to where you want the switch (no need to have it in the cabin really. Once its set, you may as well leave it) and solder a variable resistor on the end of the wires.
Next, mount your switch, tidy everything up and make sure you heatshrink all your wires to protect from water ingress.
Now its time to set it up. I suggest running the car upto the temp you want the fan to kick in (mines at about 95 degrees) and turn the knob (giggidy) slowly until the fan kicks in. Take it for a drive to try and drop the temp back down to normal driving temp and make sure the fans turn off. Normally they will turn off at about 7-10 degrees lower than kick in point so make sure you dont set it too low that it cant drop the temperature down low enough to switch them off
Team Eaton
1999 China Blue 306 GTi6 - Eaton Supercharged - 214.5bhp 181lbft
1999 China Blue 306 GTi6 - Eaton Supercharged - 214.5bhp 181lbft