Xantia cooling fans after switching off

Sl4yer · Post by **Sl4yer** » 02 Jul 2009, 23:09

Hi.

Can any Xantia Mk2 owners confirm if the cooling fans can operate when the engine is switched off? Mine don't seem to, which, with the current weather, leads to some slightly high temperature readings when restarting.

Thanks,

James

Sid_the_Squid · Post by **Sid_the_Squid** » 03 Jul 2009, 10:05

An interesting question, my 1.8 certainly keeps the cooling fans running for a few seconds after switching off the engine when its very hot, as did my HDi. However my V6 does not. I suspect a fault somewhere, I'd be interested to know if anyone has experienced this before, preferably with a fix.

Post by **CitroJim** » 03 Jul 2009, 10:27

All mine turn the fans off with the ignition..

One thing I've noticed on my V6 is it only takes a small further increase in temperature before they got to full tilt.

Sid, I wonder if yours work differently as a result of the LPG install in an attempt to keep underbonnet temperatures down when stopped.

My old 205GTi would run it's fans with the ignition off and several times people reported flat batteries as a result...

Xaccers · Post by **Xaccers** » 03 Jul 2009, 10:55

Cassy's fans will kick in if the ignition is off, sometimes a few seconds or so after I've gotten out of the car.

Sid_the_Squid · Post by **Sid_the_Squid** » 03 Jul 2009, 11:03

Sid, I wonder if yours work differently as a result of the LPG install in an attempt to keep underbonnet temperatures down when stopped.

Jim, AFAIK the car is unaware of the LPG system, certainly in terms of the various ECU's, seeing as this system was hacked in place by Micky Mouse himself I very much doubt he would have had the skill or even inclination to touch the bitron unit.
Also my totaly unmodified HDi used to run the fans after switch off.

It seems a very controlled thing, the fans only run for about 15 seconds post switch off, and only if they were running before the ignition was switched off, i.e. you had AC on, or the temp was above threashold. Sadly I cant remember if any of my mk1's did this, its been a few years.

Prehapse its only a MK2 thing?

Post by **leithant** » 03 Jul 2009, 12:35

My '95 Mk1 VSX does this, so not just a MK2 thang.

Clogzz · Post by **Clogzz** » 03 Jul 2009, 12:38

My Mk I used to, for no good reason, but no longer does.
There was a dodgy crimp connection in the socket into the inner wing near the battery.
The wires from the brown sensor to the Bitron pass through there.

The fans are allowed to stay on at low speed, or turn back on after switching the engine off, for a maximum of 6 minutes, timed by the Bitron.
It’s common for the fans to turn on at low speed on the accessory position when returning to the car with a still hot engine, even after 15 minutes, caused by rising heat.

oscarloco · Post by **oscarloco** » 04 Jul 2009, 00:34

Thank God, I'm not alone! My ZX does it sometimes (well, most of the time). I hear the fans cick in and if I turn off the car, they shut down. If I start it again in the next 5 minutes or so, they turn on at high speed. So if they are on, I stay in the car until they turn off to avoid unnecessary stress on the radiator (one of the bases is faulty and due to be replaced anytime soon) unless I'm in a hurry.

jmd · Post by **jmd** » 04 Jul 2009, 01:26

My Xantia HDi 110BHP fans die when the engine is switched off. My 1.9 Td ran for a few seconds after switching off the engine

dnsey · Post by **dnsey** » 04 Jul 2009, 07:30

Isn't there a sticker under theh bonnet warning that the fans may start up even with the ignition off? My Mk1 and 1.5 both used to do it on occasions.

Clogzz · Post by **Clogzz** » 04 Jul 2009, 13:14

Thank God, I'm not alone! … they turn on at high speed.

Hi Oscar,

If they do it when the engine is cold, there’s a sensing fault.
One of my wires to the brown sensor measured 3 Ohms I think, not enough to add to the 2KΩ-plus of the sensor, but still a dodgy connection that sometimes went high to switch to high speed.
Since I bypassed the dodgy crimp connection in the socket into the inner wing near the battery, the fans have never gone to high speed.
That’s in an area where we get 30ºC every day for over 3 months in summer.

sticker under the bonnet

Hi dnsey,

No warning sticker because the Xantia fans are inaccessible from the engine room.
The radiator totally fills the front, and removing the fans starts with the removal of the front grill.