Engine didn't turn off

[Sloanie]

After stopping the car then pulling the key out of the dash then locking the car the wife then tells me that the engine is still going. There were no warning lights or anything.
I then unlocked the car and put the key in then drove it to the local VW dealership but they had never heard of it happening. Anyway when I stopped the car and pulled the key out everything shut down as normal and the few times after that.
Any ideas what could be causing it?
I have a 2011 b7 passat.

[ian]

I have heard of this happening in older cars where there is a carbon build up,and the carbon get very hot and keeps the engine firing ?

[macdoc]

After stopping the car then pulling the key out of the dash then locking the car the wife then tells me that the engine is still going. There were no warning lights or anything.
I then unlocked the car and put the key in then drove it to the local VW dealership but they had never heard of it happening. Anyway when I stopped the car and pulled the key out everything shut down as normal and the few times after that.
Any ideas what could be causing it?
I have a 2011 b7 passat.

If your Passat is a diesel, it may have been in the middle of a DPF regeneration procedure - when the engine is turned off, the cooling fans are switched on at 100% (they are roaring fast). The sound heard may have been mistaken for the engine to be still running.

[Umai Naa!!]

I went through this with a customer the other day on a B7 actually.

Very unusual indeed, if it is in fact starting up again.

But as per above, the fans and electric water pump will kick on and cycle, to stablise temperature preventing heatsoak.

[Rocket36]

If it's your wife telling you and not seen first hand, I'd almost bet my house that it's just the fans continuing on a timer.

[Sloanie]

The fans come on now quite often even on very small trips. The first time it was definitely louder and it may have been in the middle of a DPF regeneration as my car is diesel.