Golf Mk5 1.6 FSI - Rad Fan Help

[TheArchitect]

I've read up on various dedicated forums and for the life of me no one has actaully given a straight definitive answer to this issue. Wel not one that I was able to decipher from all the technical jargon being spouted. So I'm hoping no the BCF crew can assist.

The radiator fan on my 2005 Golf 1.6 FSI wont turn off for ages after the car has been used. It comes on as soon as I start the engine and stays on for about 30 minutes after the engine has been switched off. I can turn the engine on then off literally within seconds and the fan will kick in and stay on for well over 20 minutes.

So anyone have any experience with this problem? I've gathered that it's a common fault however, the fix doesn't seem to be so common.

Any advice/diagrams/video tutorials most welcome. I'm technically restarted on these matters so please bear with me if I ask stupid follow up questions.
____________________
GSXR 600 K6 - Stolen
GSXR 600 K6 - Stolen
MT09 - Almost stolen

[James83]

Working backwards, the fan turns on because either the ECU tells it too. The only reason the ECU turns the fan on is because the engine is above a certain temperature, or that it thinks it is.

So, either:
- The coolant temp sensors gone and is reporting high temps (hint - the smart money says its this)
- The wires connecting the temp sensor are broken or disconnected, so the ECU has to assume the worst - unlikely, you would have a check engine light.
- The fan has a short circuit - Unlikely, as it wouldn't turn itself on/off automatically, just run your battery flat
- The ECU is fubar - you would likely have a check engine light and/or other engine problems

So, if I was you, I would grab one of these https://www.gsfcarparts.com/parts/cooling-heating/cooling-system/coolant-temperature-sensor (Appropriate one for your car) and swap it out. If you're unsure how to fit it, I would then google 'Fitting a coolant sensor Mk5 golf' and watch the first video you find.
____________________
Jonathan A wrote: tart.

[-]

Common problem. Could be temp sensor, but also smaller of the 2 fans not working. Google it, loads of info.

[bugeye_bob]

Run VCDS and check for any error codes would be my first port of call on any VAG with issues,
just because there is no error light on doesnt mean the ECU is happy with everything,
Typically CTS`s fail on VAG`s and that rarely brings up a EML.

You can test if the fans operate again with VCDS, lead and software can be had for around £30 from auction sites,
PM me if you need any help with the correct lead.

[TheArchitect]

Cheers for info everyone.

Is there any way to test the Temp Sensor to possibly eliminate it as the problem? Don't want to spend more than I have to, obviously.

From further googling it transpires that the gadgetry that controls the fans doesn't actually talk to the ECU, hence no error codes to be expected.
Reading up more, sounds like there is more than one fix for this and it's just a case of trying them out and seeing which one does the job.

Some more info if it helps...
The temp is always normal and never goes above 90 degrees, no matter how long I drive.
Small fan doesn't come on, only now realised this. I don't think it's been working for a while.
It has now drained the battery on two occasions. Both times after a short drive.
____________________
GSXR 600 K6 - Stolen
GSXR 600 K6 - Stolen
MT09 - Almost stolen

[bugeye_bob]

[TheArchitect]

[Bikeless]

I've tested temperature sensors with a multimeter before, they change resistance as engine temp rises.

[-]

I have VCDS in Kent.
____________________
TZR250 2MA road, TZR250 1KT road, TZR250 2MA race, TDR250, YZF-750R Boost colours.
Jaguar S Type 3.0 V6 Sport R, VW Transporter T5 GP LWB Shuttle 140ps DSG.

[TheArchitect]

Problem solved with a replacement Coolant Temp Sensor.

All is running as normal now.

thanks for the info all..
____________________
GSXR 600 K6 - Stolen
GSXR 600 K6 - Stolen
MT09 - Almost stolen