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Author Topic: Radiator fans starts running intermittent  (Read 3621 times)

Offline o-kruse

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Radiator fans starts running intermittent
« on: August 14, 2019, 12:51:50 am »
Hi.
I have a problem with both radiator fans start running intermittent max speed, without no reson and draining battery in minutes.
This with cold engine and also warm sometimes.
have been able to trigger condition by starting engine and then turn off after a minute or a few.
has anyone any experiance with this?

Offline muff1991

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Re: Radiator fans starts running intermittent
« Reply #1 on: August 14, 2019, 09:59:05 am »
I had a similar issue on my old mk4 gti. Turned out to be one of the temperature switches. Try to get yours scanned with VCDS and see if anything flags up. If not, I’d look into the fan switch and coolant temperature sensor.


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Offline o-kruse

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Re: Radiator fans starts running intermittent
« Reply #2 on: August 14, 2019, 12:34:44 pm »
I had a similar issue on my old mk4 gti. Turned out to be one of the temperature switches. Try to get yours scanned with VCDS and see if anything flags up. If not, I’d look into the fan switch and coolant temperature sensor.


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I have got it scanned at VAG workshop and they said no errors, hope they know what to look for?
Have changed complete fan assy, including fan switch which is in fan housing.
We changed one sensor on left hand, no change.

I read about one more under the Generator by waterpump, so ordered one and will try to change that one also.
Do you know if the VCDS can read a intermittent fault, meaning that is it able to register a previous fault that is ok when scanning?
« Last Edit: August 14, 2019, 12:38:13 pm by o-kruse »

Offline muff1991

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Re: Radiator fans starts running intermittent
« Reply #3 on: September 04, 2019, 11:47:32 am »
sometimes it will pick up old codes, intermittent codes and solids. when you say sensor on left hand.. do you mean gear box side (Coolant temp sensor)?

Offline o-kruse

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Re: Radiator fans starts running intermittent
« Reply #4 on: September 05, 2019, 04:08:36 pm »
Yes, on gearbox side, decided to change back to original, no change.
After this cleaned some terminals, on fusebox, incl ground and replaced battery, which is only 3 yrs., but probably damaged by all this draining.
Strangely, the failure has not been there since, two weeks gone and crossing fingers :-)

Offline muff1991

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Re: Radiator fans starts running intermittent
« Reply #5 on: September 05, 2019, 04:17:16 pm »
Yes, on gearbox side, decided to change back to original, no change.
After this cleaned some terminals, on fusebox, incl ground and replaced battery, which is only 3 yrs., but probably damaged by all this draining.
Strangely, the failure has not been there since, two weeks gone and crossing fingers :-)
sounds like you may have found the culprit somewhere along the lines then. fingers crossed its all good now  :happy2:

Offline LuciaDoods

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Radiator fans starts running intermittent
« Reply #6 on: October 16, 2019, 10:02:31 am »
Should my radiator fan start when the car is cold and I engage the A/C? Or does the Radiator fan only run at a set temp. My A/C fans runs but I have never seen my radiator fan run, at all.
Im not sure if the fan is faulty or not as my standard temp gauge is useless.

Any info would be great. Thanks

Offline GVK

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Re: Radiator fans starts running intermittent
« Reply #7 on: October 17, 2019, 10:57:14 am »
Fan will usually cut in with AC yes.