Vwmk3vr6 1 Posted September 22, 2020 Report Share Posted September 22, 2020 On a mk3 vr6 once car gets to temp radiator fans kick on and stay on i believe since no matter the weather when i come to a stop they are on and don't go off till car is off and stay on for five minutes like they should but i dont think they should be on the whole time after car is warmed up??need fixed i dont want to have to buy new fans😔i have unplugged the yellow 4 pin sensor in coolant flange and fans turn off so it is working i guess .any help os appreciate so much. Link to post Share on other sites
Philly-R6 28 Posted September 23, 2020 Report Share Posted September 23, 2020 It does sound like one of your temperature sensors is "iffy". There is a comprehensive post regarding the cooling system over on the-corrado.net: https://the-corrado.net/topic/38215-the-definitive-vr6-cooling-guide/ The post explains what the various sensors do and how to identify them (it makes reference to early and late VRs - yours would be late). Vwmk3vr6 1 Link to post Share on other sites
Vwmk3vr6 1 Posted September 23, 2020 Author Report Share Posted September 23, 2020 Do you know of vag com would detect this? I have vag com but so new to vag com so would have to figure out how? so far only clear codes and throttle adaption i have done. Link to post Share on other sites
Philly-R6 28 Posted September 24, 2020 Report Share Posted September 24, 2020 VAG COM (now called VCDS) won't help here - other than seeing what the ECU thinks the coolant temperature is. The radiator/fan system is simple - if one of the sensors thinks the coolant is too hot, turn the fan on. Your answer is in that post: you just have to follow the instructions on how to check each sensor in turn. Link to post Share on other sites
Vwmk3vr6 1 Posted September 28, 2020 Author Report Share Posted September 28, 2020 Would the thermostat make the difference??came with 71c and replaced with 180f?? i have replaced the three sensors and one on radiator even replaced the fcm and the heater core (car had no heat when i got it) All thats left is either one of the sensors came bad ?or the radiator? Replacing all hoses top hose is weak would that cause engine to get a little hot for fan to come on? By vcds the fan comes on at 197 but then engine voes up to 210 while idleing and holds but with fans on the whole time. Link to post Share on other sites
Philly-R6 28 Posted September 30, 2020 Report Share Posted September 30, 2020 Is the fan spinning gently (stage 1), or fast (stage 2)? Did you follow the fan test on the linked post: 1. Take the plug off the rad sender 2. Take the plug off the black temp sender in the stat housing. 3. Switch ignition on. In the rad sensor plug - red wire is stage 1, thin red/black is stage 2. The other wire is the common connection. Bridge each of the two wires in turn across the common wire and see if both speeds come on. If they do, good. 4. Bridge the black plug with a paper clip or something, does stage 3 come on? Sounds uber loud! Did your fans behave as expected? If so, the sensor in the radiator is suspect. Is the sensor faulty, or is the coolant temperature not coming down? When the radiator fan is on, does the coolant temperature drop? Is the coolant pump working? Does coolant actually flow through the radiator? Link to post Share on other sites
Vwmk3vr6 1 Posted September 30, 2020 Author Report Share Posted September 30, 2020 Yes did fan test all checks out ok. And water pump is new and working. Problem is fans don't cool engine to shut off I guess new radiator i don't know only changes done is thermostat from 160f to a 180 f stock one.and the front grill Link to post Share on other sites
Vwmk3vr6 1 Posted November 25, 2020 Author Report Share Posted November 25, 2020 On 10/6/2020 at 6:23 PM, Harry-vr6 said: Ye definitely replace it as they can Fail, mine is under 1 years old and has failed as it sticks in my mk6 golf need to do that then back on to my vr project. Hopefully things work out for you Link to post Share on other sites
Vwmk3vr6 1 Posted November 25, 2020 Author Report Share Posted November 25, 2020 Just now, Vwmk3vr6 said: Well done everything and fans still run once they reach temp 197f they dont shut off till engine is shut off and after the 5-10min but if i let it idle they never turn off stage 1 with the 71c thermastat they came on and shut off but was told not to run that cold of a thermastat so put the 180f back in going to try low temp switch next 😭 Link to post Share on other sites
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