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Purple
12-12-2006, 17:18
Is this what happens in your clio?

When I switch off the engine while the rad fan is still running, and leave the key in the first position on the ignition, the rad fan takes a long time to switch off ( I think more than 5 minutes).

But when I switch off the engine while the rad fan is still running, and turn the key to the second position on the ignition, the rad fan switches off much quicker (from a few seconds to about 2 minutes).

It's as if when in first position, it's on a long duration timer. But in the second position, the fan switches off when the rad is cooled.
cliolord
12-12-2006, 22:16
yes. This use to happen on my old 16v. Leaving the ignition on but car not running once the fan has cut in, it will cut out as soon as the thermo switch has cooled down. Turning the ignition off seems to put the fan control into a default 5min+ duration for some reason. I havent noticed it on my current 16v
Purple
13-12-2006, 01:32
Thanks for the feedback.

It's annoying that I have to wait (with the key in second position) for the fan to stop before walking away from the car. Think I will wire in a 3 minute turbo timer one day that's linked to the second position. That should give it enough time to "sense" the rad and switch itself off.
summeh
13-12-2006, 07:51
If I remember correctly, when the ignition is switched off with the fan running. The cars "anti perculation device" is activated. This being the patheticly small water pump on the left side down below the airbox. Small black cylinder with 2 small water pipes going in to it. This is supposed to run for 8 minutes.

With the ignition left on, the anti perculation device is not activated, thus the fan switches off when the temperature inside falls below that of the activation level for the fan switch.

2 minutes does seem a long time, but then you are in very hot conditions are you not? My fan only ever seems to run for about 30 seconds at a time, off for 30 seconds and then back on for 30 seconds and so forth (if engine running).
summeh
13-12-2006, 07:53
Thanks for the feedback.

It's annoying that I have to wait (with the key in second position) for the fan to stop before walking away from the car. Think I will wire in a 3 minute turbo timer one day that's linked to the second position. That should give it enough time to "sense" the rad and switch itself off.

It would not be a problem to leave the fan running and walk away from the car... It's doing what it was designed to do. Just thank yourself that it's not a puegeot, they are even worse, or better maybe, depending which way you view it?
Purple
13-12-2006, 08:58
2 minutes does seem a long time, but then you are in very hot conditions are you not?
Yup, that's me, alright. But it's been a chilly 30C lately with the monsoon rains hitting us everyday. :D Still takes at least a minute most of the time. And I feel uncomfortable letting the fan drain the battery for 8 minutes, if I walk away.

What's the anti perculation about?
summeh
13-12-2006, 09:02
Something to do with stopping the water from boiling :wink:
stan
13-12-2006, 10:11
Its so when you switch the engine off, water can still be pumped round the coolant sytem, as temps still rise after the engine is off.
Purple
13-12-2006, 10:52
That's a very good idea for the climate I live in. But is there a way top shorten the anti-perculation to something around 3 minutes?
summeh
13-12-2006, 13:23
Why would you want to do that?

If you are using your car enough to warrenty the system being activated when you leave your car, I think you can safely say that your alternator will be charging your battery up enough to compensate.

The water pump is a tiny pathetic thing which I doubt draws that much current. The fan obviously does though but I'm sure Renault have tested this system quite a lot.

As said before Pug's are even worse. My girlfriends 306 always seems to have the fan left running during the summer months. We've never had a problem with the battery being drained.

I would say it's a good idea to keep it as Renault intended.

However, if you live in the UK, or someplace else that they use salt a lot in the winter months then you may find that the electrical connections to the pump are corroded so it doesn't work anyway!
Laine_16v
13-12-2006, 18:53
The Aux Water pump is a rubbish thing, its not really needed.

Hence why 172's/182's no longer have them.
Purple
14-12-2006, 01:52
Yeah, don't think I have seen this in many cars.

I leave the engine bonnet open and idling for a minute or 2 after a hard run anyway. But now that I know that rad water still flows after the engine is off, I think it's a good idea for hot climates. It would be nice if I I could shorten it a bit to save on battery drain and alternator charging.