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Radiator fans running excessively

M

Mchandler6

Passed Driver's Ed
2012 mk6 gti with 49,460 miles on the odometer. Cobb accessport stage 1 high boost map has been flashed for the past 11k miles with no issues and no other mods.

Noticed for the past four days my radiator fans seem to be running excessively and at odd times. I attached two photos this morning showing all temperatures on my accessport as well as ambient on the dash. Fan load is 32% and the car was just started and the car isn't even close to operating temp. The other day in highway cruising fans were at 65% load and the car was as usual on any other day. Can anybody shed some light on this? No CEL, no recent mods or changes. I've done some reading but this seems to happen to people that have had their ECU opened up and damaged. I'm the second owner of this car but have had it since December of 2015. Thanks in advance.



 
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S

simpson110

Ready to race!
A/c on? That will turn on the fans
 
S

simpson110

Ready to race!
Maybe try turning it off.
 
Laimface

Laimface

Ready to race!
If your AC is on, fans will instantly start pulling air over the condenser. As above turn your AC off and the fans will most likely stop... At the expense of you sticking to your seat haha.
 
lilonespaz

lilonespaz

Drag Race Newbie
Yeah try turning your AC off and seeing if that decreases load.. then you will know that its normal. Im not sure what the normal fan speed load should be as i do not monitor that...

I use my AC all day ever day too lol and i do not notice the fans...
 
T

thzpcs

Passed Driver's Ed
As many have said, having the A/C on will turn on the fan since the condenser has to have air flowing over it at all times.
 
Carbon Steel

Carbon Steel

Go Kart Champion
I am kind of out of the loop, but your comment reference issues with the fans running at odd times, all the time etc. was associated with cars that were tuned via opening the ECU.

Then either thru inadequate water proof sealing, water seeped in and then caused the issue, or the process of opening the ECU, put stress on the board, possible minor fracture on board that later, thru vibrations increased crack on board and caused the ECU to malfunction.

I hope it is your A/C.
 
damagi123

damagi123

Go Kart Champion
Carbon Steel said:
I am kind of out of the loop, but your comment reference issues with the fans running at odd times, all the time etc. was associated with cars that were tuned via opening the ECU.

Then either thru inadequate water proof sealing, water seeped in and then caused the issue, or the process of opening the ECU, put stress on the board, possible minor fracture on board that later, thru vibrations increased crack on board and caused the ECU to malfunction.

I hope it is your A/C.
Click to expand...

i came to post the same thing but if its cobb its flashed via obd not bench flashed. unless it was opened and bench flashed at some point prior. If youre a second owner id look into whether the ECU case was ever opened. If it was thats probably whats happening.

The master tech at my dealer said there are way more failed ECUs and ECU solder issues that havent been opened than theyll admit. And those fans running excessively is always one of the symptoms
 
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MrFancypants

MrFancypants

Autocross Champion
This isn't a fun thing to read. I've noticed my fans coming on when I start the car cold with the A/C turned off. Original owner, never tuned.
 
H

HoliMoli

New member
Hope this helps.

I had this issue about 8 months ago. I would turn my car on drive it alittle and all of a sudden my fans were on at full blast. Turned the car off and they shut off. It had this cycle for a good 2 weeks. After that every time i started the car or even clicked the on switch the fans were on full blast even from sitting 24hours. It sounded like a tornado under the hood. I took it to the dealer and they said my fans switch was bad. I ended up buying new fans and installed them. Started the car and still the same problem. Went back to the dealer and told them new fans still the same problem. They took it in and called the techs in Germany and diagnosed it with a bad ECU. New ECU was installed and problem fixed under warranty and they even refunded my 100 bucks for the bad diagnose.

For Reference my car wasn't tuned so the ecu was never cracked open. It was just a bad case of a failing part.
 
lilonespaz

lilonespaz

Drag Race Newbie
Short Bus said:
This isn't a fun thing to read. I've noticed my fans coming on when I start the car cold with the A/C turned off. Original owner, never tuned.
Click to expand...
well it is getting hotter out...
 
MrFancypants

MrFancypants

Autocross Champion
lilonespaz said:
well it is getting hotter out...
Click to expand...

This is true, but even at 100C ambient I wouldn't think the fans would kick on for a cold engine (A/C off). I do know that the fans turn off at some point, when I park the car back in the garage they'll fire back up when I turn the car off.

I'm probably just being paranoid. 99.9% of the time I have the A/C on so a fan firing up on cold start is normal. There's also a number of other, less expensive issues I could be having if something is off (sensors, fan controller, fans themselves, etc).
 
damagi123

damagi123

Go Kart Champion
Short Bus said:
This is true, but even at 100C ambient I wouldn't think the fans would kick on for a cold engine (A/C off). I do know that the fans turn off at some point, when I park the car back in the garage they'll fire back up when I turn the car off.

I'm probably just being paranoid. 99.9% of the time I have the A/C on so a fan firing up on cold start is normal. There's also a number of other, less expensive issues I could be having if something is off (sensors, fan controller, fans themselves, etc).
Click to expand...

even if it does turn out to be the ecu i got a used one at a junk yard and had it paired to my car for like... 160 bucks i think man
 
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