Hi,

I have a 2005 Octavia 2.0d.

The larger of the 2 fans (the one on the right of the engine bay as you look at the car from the front) won't stop running when the engine is switched off. It will get up to speed, stop, and then immediately start again.

Any ideas as to what the problem might be, please?

doesnt that stay running until the engine has cooled down?

It will, mine has done it occasionally

The Fan shouldn't stay on any longer than a couple of mins after engine switch off. I have had the same problem in the past. Things to check:

1. Fuse box in the engine bay - make sure that isn't wet. If it is disconnect the battery. Remove every fuse (make sure you make note of what goes where) and get a hair dryer on it for a good hour or two. If your mechanically minded then its easy enough to completely remove the fuse box and dry it out indoors as this is what I had to do. Another way of doing it is leave the fuse box cover off and go for a good 3-4 hour drive on the motorway. But this option only works in summer.

2. Fan loom connector block - Disconnect Battery, Remove engine under tray and then disconnect the Fan loom connection. Its on the lower passenger side. Use an air duster can (like the ones you get for laptops etc) and clean both parts of the connection. Then use a hairdryer again for about 30 mins to ensure it's completely dry.

If its not either of those then im afraid I don't know what else can be causing it. Mine was a combination of both water in the fuse box and the connection. This was due to going through a car wash with an under chassis wash.

Always disconnect the battery before you start messing about with it. Last thing you want is the fan coming in midway through whilst your hands are near it. Also when using the Hairdryer don't keep it in one place. Keep moving it about.

HTH

Carl

The Fan shouldn't stay on any longer than a couple of mins after engine switch off. I have had the same problem in the past. Things to check:

1. Fuse box in the engine bay - make sure that isn't wet. If it is disconnect the battery. Remove every fuse (make sure you make note of what goes where) and get a hair dryer on it for a good hour or two. If your mechanically minded then its easy enough to completely remove the fuse box and dry it out indoors as this is what I had to do. Another way of doing it is leave the fuse box cover off and go for a good 3-4 hour drive on the motorway. But this option only works in summer.

2. Fan loom connector block - Disconnect Battery, Remove engine under tray and then disconnect the Fan loom connection. Its on the lower passenger side. Use an air duster can (like the ones you get for laptops etc) and clean both parts of the connection. Then use a hairdryer again for about 30 mins to ensure it's completely dry.

If its not either of those then im afraid I don't know what else can be causing it. Mine was a combination of both water in the fuse box and the connection. This was due to going through a car wash with an under chassis wash.

Always disconnect the battery before you start messing about with it. Last thing you want is the fan coming in midway through whilst your hands are near it. Also when using the Hairdryer don't keep it in one place. Keep moving it about.

HTH

Carl

Thanks to everyone for their replies - especially to Carl.

Tomorrow - when it's hopefully warmer - I'll take off the connector block and see if there's any corrosion or damp.

Kind regards

My cooling fans were coming on for no reason even during the night flattening the battery, I took it in to my local dealer who could find nothing wrong gave me the car back and it never did it again, that was at least 6 month ago, I did spray wd40 in to the conector the day before so mayby that cured it.

http://briskoda.net/forums/topic/164769-cooling-fans/page__p__2014281__fromsearch__1entry2014281

Edited 26 December, 201015 yr by The The

Hi I am currently having the same problem with my car which is the same model and year as your one.

I have been told by the garage that my E-box is corroded and they have ordered a new 1, they have also said there is corrosion caused by water in the wiring and the ECU. I'll re-post when they change the E-box in a couple of days with the results.

I have had my same problem sorted now. They fitted a new E-box which solved that 1. Mine was corroded with water damage. Maybe you should get them to check that.

However I've had to take it back due to my engine management light coming on and restricting power to the car (it's like driving a 1.0 fiesta!!) but it's something they have done so I'm not paying for it!