Fan kicks in when parked after a drive.

[Scott H.]

Hello all,

Not sure if this is normal or what I can do to fix it but...

Once I have driven my car and it's up to operating temperature say 10-15mins down the road minimum. If I then park up say at a friends while I pick something up as I know im going to drive away again in a few monents and leave my car running the fan kicks in after few minutes. The needle still sits in just above the middle of the gauge, (which I think is normal?).
I haven't had the fan come on whilst in slow moving traffic. Not that I have been in many for a long period anyway. But I normaly sit in some just before work, stop starting for about 1/4-1/2 mile and it hasn't came on. Even after a 25mile drive.

Once the fan has came on whilst parked it runs for a few minutes and then goes off again.
The coolant is between the min and max slightly above half way and im not sure when it was last changed.
My heater gets hot as normal when I have that running too, which is normal.

Im looking at replacing the coolant sometime soon anyway aswell as a new tank so would you think this would fix the problem? If it even is one:/

 

[Rhauri]

My initial response is... what problem?

As long as your car is keeping temperature mate (from your description of the needle position, it is), that's all that matters. I wouldn't worry about replacing the tank either, you're not going to gain anything from that what-so-ever.

The main thing to really worry about with a cooling system is leaks, and then the thermostat. If you've got no leaks, and your fan is kicking in when the car is idling at a stand still (thermostat) - then you're good to go. When driving in slow traffic, even if its stop start, some air will be going through the radiator - which may be enough to keep the coolant at the correct temp. The fan only kicks in when the coolant is getting close to or even rising above where your system wants it to be. When its back down to the optimal temp, it shuts off - if air is running through the rad, i.e. when driving - then the fan doesn't need to spool up for obvious reasons. So for that reason, fans should only spool up when the car isn't going anywhere but the engine is running.

A full coolant change will be a good thing if you are unsure when it was last done, or if it was over 3 years ago as the +/- tolerances of the coolant reduce and you leave your coolant at risk of freezing up in the winter or overheating during a hard drive/hot day.

Otherwise pal, your cooling system sounds very healthy indeed.

 

[MartinR]

Perfectly normal

 

[Scott H.]

Tanks for the response mate, thats great news!

I was going to change the tank just to make it look new and clean, as mine is all yellow and old. There only £13 from ebay

Now I just got to read up on how to flush, bleed and fill up the system

Cheers!

 

[Budgie]

If your header tank is old and yellow looking- remove it. Stick a bit of warm water and fairy liquid in. Pour half a cup of rice in. Shake it all about. Flush it clean.

Job's a good'un.

 

[Rhauri]

The labour involved in doing a full coolant change isn't much at all - its more about knowledge, and bleeding & refilling a coolant system *can be* tricky for a self taught first timer. If you could find a local mechanic willing to do it for you (cash) I'd probably go for that option. Whats more, they will be able to get hold of OE spec coolant for half the price you can, so overall - it'll be very close in terms of cost.

But DIY is satisfying so do what ever you're most comfortable with

 

[Scott H.]

Already bought the new tank now so thats in its way lol! Popping to Reanult some day this week to get the Type D for £11.63.

Tbh I think I could give it ago myself, and as you said DIY is much more satisfying! The car hasent been in the garge once *touch wood* and iv replaced the brakes, oil & filter change, fitted coilovers, replaced ball joints and track rod ends If I get really stuck the Girlfriends Dad is a mechanic so sure he will come out and give me a hand.
I had to bleed and fill up the system on my sister Mini not that long ago as it sprung a leak and she rang up asking why her fan was coming on in traffic and the niddle was going over half way! As there was no water in the system. I was going to replace the rad for her but them Mini's look hard work in that engine bay, no room!

 

[Rhauri]

Aaaah, sounds like you're not afraid to pick up a ratchet then and its handy to have a friendly mechanic at hand should you need one!