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Have owned my 2016 Touareg TDI for 3 weeks, something happened today that was new to me.

I drove 21 miles on state highway (70 mph, flat) and parked. The fan ran for nearly 10 minutes after I shut the engine off. Freaked me out because it has never done this before. After an hour drove home (21 miles) and when I parked the fan did not keep running.

Temperatures were not excessive, about 87F ambient, the coolant was right in the middle where it always is.

What is this?
 

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Engine temp sensor failure is the most common cause. Many different touareg engines. Most engines have two or three temp sensors. The trick is to figure out which sensor(s) you need to replace.
 

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It is probably doing a regeneration of the emissions system. When the build up of particles in the converter get to a certain level it gets burned off in the catalytic converter which raises the heat big time,so the fans run to cool the engine area. My treg didn't do it nearly as much as the 2.0 TDI JSW I had. The more short trips you have will increase the regens. These systems need to be run to get the temps running at full temps, short trips aren't great for TDI engines.
 

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Have owned my 2016 Touareg TDI for 3 weeks, something happened today that was new to me.

I drove 21 miles on state highway (70 mph, flat) and parked. The fan ran for nearly 10 minutes after I shut the engine off. Freaked me out because it has never done this before. After an hour drove home (21 miles) and when I parked the fan did not keep running.

Temperatures were not excessive, about 87F ambient, the coolant was right in the middle where it always is.

What is this?
My 2016 did the same thing once in the 3 months I have own it. I figured it might have been a regen thing. It has not done it since.
 

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I don't recall which car it was but seems to me it was a 5 series that did the same thing. My understanding is that it insures residual heat from the stopped engine (ie a hot cylinder) doesn't cause a hot spot and I'm only guessing here but presume an electric water pump kept th coolant moving during those few minutes
 

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I don't recall which car it was but seems to me it was a 5 series that did the same thing. My understanding is that it insures residual heat from the stopped engine (ie a hot cylinder) doesn't cause a hot spot and I'm only guessing here but presume an electric water pump kept th coolant moving during those few minutes
This is usually the case. If engine and ambient temps are above a certain threshold, the electric water pump(s) and rad fan will run for a few minutes to bring down temps and ensure the cylinder heads don't warp due to convection heating.
 

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The length of time it ran would indicate a regen..... depending on conditions, if I recall correctly, this time can go as long as 15min on some models (can't recall if that's the 2L value or the 3L one at the moment)
 

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It is interesting that all the gasser cars I've had never had any run on fan motor when the car was shut down. When the TDI's don't get enough high speed run time the unburned particles build up in the catalytic converters. Regen then sprays fuel into the hot cat and burns off the build up . As you can imagine the heat from the burn process creats big time heat that needs to be cooled with the fans. If you get out of the car when this is going on you can feel the heat outside the car. Both my TDI's 2.0 and 3.0 experienced this process.
 

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Although you may have read about regens, you don't quite understand what you are talking about or trying to explain to others. Gassers don't have to deal with the same DPF systems as the diesels do, so since they don't perform "regens" on these non-existent components, they wouldn't exhibit the same "running cooling fans" issues.

The running fans have nothing to do with cooling off the "cat" (especially since it's a DPF). You do not want to cool down the DPF.... the whole system works on getting the DPF hot and maintaining it HOT in order to allow it to burn off the SOOT and transform it into ASH. You do not want to cool the DPF as you would be impeding it from doing its job if you did.

The cooling fans run in order to stabilize and protect all of the engine stuff that was previously under a lot of stress and demand trying to raise up the DPF temp prior to the user shutting off the car. The system is attempting to keep your turbo and other critical components from experiencing too much heat soak, and other associated damage due to the elevated temps and hot fluids throughout the entire system.
 

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On our 2012 I will notice the fans running for about 30 seconds after a drive home in 90+ degree weather. There was one time where it ran for an additional 5 minutes but that's only been once since we've owned it. Not any real concern from me as it seems like the car knows what its doing.
 
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