Fan won't stop spinning

[lukemk5gti]

In the last week or so I've noticed the main circular fan at the front of the engine (passenger side) is on full power.

You can hear it when the engine is idling and then when you turn the engine off it does turn off also but it's quite noisy winding down.

Any idea why the fan has suddenly started acting up and how to fix this?

[pudding]

Still does the same with the HVAC turned off or set to 'ECON'?

Check the chunky fuses in the engine bay.  If everything is fine, it's usually the fan controller, which I believe is part of the motor, so it'll be a new fan unfortunately.

[lukemk5gti]

Haven't turned my AC on in about two years since the compressor kicked it and I couldn't be bothered paying €1,000 for a new one!

Why is it turning on? Dodgy switch just making it revert to fault and turn on assuming the worst and reacting accordingly?

[pudding]

I've heard if any of the slow speed fuses blow, the fast speed kicks on as a safety precaution, hence that little check.

If they're OK and the temp gauge reads OK, and the ECU coolant signal reads OK, it'll be a dud fan then.  Some kind of internal fault I expect, but another 'known' MK5 problem!

[shoaybmakda]

Mine seem to spin when I switch the car off when the air con on. Not sure if that’s normal? They do eventually switch off though

[lukemk5gti]

Damn, guess it's just one of those things you put up with if it's not the fuse.

Not a hope I'll spend money replacing that fan because other mods always seem to take precedence.

Thanks pudding!

[theminty1]

Check and see if the wee one turns at all. If it doesnt i had the brushes in the small fan were stuck so not making the connection. If you have vagcom i believe you can manually turn them on
A new fan is expensive so you can 'break' into the small fan. I just cleaned out the brush holders. Various links on the net and quite common.

[OEM+ DUB]

Had exactly the same problem as above a few years back - big fan running constantly when aircon engaged (sounded like Concorde when stationary!).

Chose a freezing cold winter morning to strip out the fan pack, as you do...  Just raised the front of the car using ramps, removed the lower plastic tray/shield dropped the fan pack down and out underneath the car.  Carefully bent the tabs on the motor housing of the small fan to open up the casing and found the brushes stuck in their housings (from memory the spring pushes them up into contact so when muck gets in there gravity does not help).  Cleaned them up and freed them off, reassembled, returned fan pack to car and all sorted.

Been fine for at least three years now and all it cost me was 30 minutes of my time and some contact cleaner.

[theminty1]

Had exactly the same problem as above a few years back - big fan running constantly when aircon engaged (sounded like Concorde when stationary!).

Chose a freezing cold winter morning to strip out the fan pack, as you do...  Just raised the front of the car using ramps, removed the lower plastic tray/shield dropped the fan pack down and out underneath the car.  Carefully bent the tabs on the motor housing of the small fan to open up the casing and found the brushes stuck in their housings (from memory the spring pushes them up into contact so when much gets in there gravity does not help).  Cleaned them up and freed them off, reassembled, returned fan pack to car and all sorted.

Been fine for at least three years now and all it cost me was 30 minutes of my time and some contact cleaner.

Sounds the same as me apart from took me 3 or 4hrs. Im not the best at these things.

Note I took off the intercooler hoses for better access and changed the leaking seals while I was there  .

For info if the big fan is on the small one should be as well. The big one is not normally on at full (Concorde) speed. It will be on but just cruising with the small one

[pudding]

What are the operating modes / conditions for the fans?

I sometimes get the hovercraft noises from El Biggo Fan when the A/C is set to LO, and it's a hot day, and it's been sat in traffic.  I'm guessing that could be a combination of A/C + engine cooling requirements?

But what would be handy to know is when the small fan comes on, when the big one comes on and what speeds they should run at etc, just so I know all is well up front.   They're never on under normal driving situations.....that I've noticed at least.

Cheers

[theminty1]

When my wee fan was stopped(broken) the big one was on and it sounded like it was going to take off.
When the small one was fixed everything was much quieter. The big fan runs now but in comparison to before it is a lot quieter almost almost stopped. I think as the car gets hotter its speed will increase.
As far as I am aware the small fan is for the aircon and the big one is for the engine.
I had a MK2 TT from new and as soon as it sat stopped but engine running the big fan could be heard to come on after about 30sec. It is similar in the Golf now.

I am sure someone will be able to confirm

[pudding]

Thanks Minty