Fan coming on, A5 Sportback Sline

metricspaces

Hi folks - wondering if anyone has any thoughts on this.

The fan has recently started to come on after I stop the car. It is a 2012 A5 Sportback Sline. I have this A5 3 years and this has never happened. Now when I drive 40km to work, stop the car, get out and lock it, the fan is staying on for 5 minutes.

During the summer there was one or two really hot days where the fan stayed on after I stopped the car. I thought with the hot weather this is ok, it made sense. But today the temperature was just 14 degrees.

Nothing else is jumping out at me:

• Coolant level is fine.
• Temperature gauge is bang on center before I turn off engine.
• No warning lights on dash

I used to have VAGCOM but not anymore, so I will need to get someone to check for error codes.

I think a sensor can go faulty without showing up warning light on dash right? And possibly without any error codes when you hook up VAGCOM? So I guess the quick thing to check is replacing the sensor? Is it just the coolant temp sensor?

I guess the other thing is that the fans could have gone faulty? But I am not sure this would cause the behaviour I am seeing now?

tossy

If it's diesel its a DPF re gen. To burn off the contents of the DPF it must be heated to a very high temp, if it's doing this and you shut the car off it wil run the fans at full speed to bring the temp down.

Moanin

metricspaces wrote: »

Hi folks - wondering if anyone has any thoughts on this.

The fan has recently started to come on after I stop the car. It is a 2012 A5 Sportback Sline. I have this A5 3 years and this has never happened. Now when I drive 40km to work, stop the car, get out and lock it, the fan is staying on for 5 minutes.

During the summer there was one or two really hot days where the fan stayed on after I stopped the car. I thought with the hot weather this is ok, it made sense. But today the temperature was just 14 degrees.

Nothing else is jumping out at me:

• Coolant level is fine.
• Temperature gauge is bang on center before I turn off engine.
• No warning lights on dash

I used to have VAGCOM but not anymore, so I will need to get someone to check for error codes.

I think a sensor can go faulty without showing up warning light on dash right? And possibly without any error codes when you hook up VAGCOM? So I guess the quick thing to check is replacing the sensor? Is it just the coolant temp sensor?

I guess the other thing is that the fans could have gone faulty? But I am not sure this would cause the behaviour I am seeing now?

My wife's 2011 A6 does the same thing even after a long drive. It's normal I believe.

WillyWonkaBar

My 2014 A4 also does this.

metricspaces

It is normal for the fan to come on if the temperature of the engine is above the threshold when you stop the car. Normally this should not happen if you have just driven off the motorway though (at cruising speed!).

My drive in to work is all motorway and then about 1min from the motorway I park. So normally this should not happen, the fan should not come on as the speed of air coming through the engine when on motorway is enough to cool engine. Normally the fan does not come on. So normally all good

If I was sitting in traffic for a long period of time before turning off the engine, then yes it would be no surprise for the fan to stay on after I turn off the engine.
If it was a really warm day, then also it would be no surprise for fan to stay on, as the air temp is not low enough to cool engine.

Yes it is a diesel, so DPF re gen makes sense. Although I'm surprised this is the first time I've noticed this after 3 years of owning the car...

Moanin

metricspaces wrote: »

It is normal for the fan to come on if the temperature of the engine is above the threshold when you stop the car. Normally this should not happen if you have just driven off the motorway though (at cruising speed!).

My drive in to work is all motorway and then about 1min from the motorway I park. So normally this should not happen, the fan should not come on as the speed of air coming through the engine when on motorway is enough to cool engine. Normally the fan does not come on. So normally all good

If I was sitting in traffic for a long period of time before turning off the engine, then yes it would be no surprise for the fan to stay on after I turn off the engine.
If it was a really warm day, then also it would be no surprise for fan to stay on, as the air temp is not low enough to cool engine.

Yes it is a diesel, so DPF re gen makes sense. Although I'm surprised this is the first time I've noticed this after 3 years of owning the car...

My wife does similar driving to you. The car has 250k kms on the clock and does mostly motorway driving. It regenerates more often since we had the 'emissions fix' done and new EGR valve. Have you had the 'fix' done by any chance?

metricspaces

No. I haven't had the fix done.