2012 Passat Regen?

wvmountains

Member
Joined
Oct 27, 2019
Location
Columbia SC
TDI
2012 SEL TDI
What exactly is a “regen” with regard to my 2012 Passat SEL TDI?

Someone one on this forum said bc my engine did a regen bc both fans were run full blast and the engine seemed really hot under the hood although my temp gauge was dead on. I also experienced slight smoke and oil smell but I have no leaks under the car nor any I can see in the engine bay. Oil level perfect too.

Car runs perfectly with 132K on the clock. I purchased with 130K, so I’ve not put many miles on it. Mostly town driving.

Should I be concerned bc a forum member said this is completely normal? Also, I’m second owner and first owner had EVERY service required performed by a VW dealer.

Thanks.
 

Fixmy59bug

Veteran Member
Joined
Aug 1, 2009
Location
Las Vegas, NV
TDI
2015 Passat TDI SE
Your car has a particulate filter on the exhaust to catch all of the black soot that is inherently produced by your TDI engine.

Eventually that DPF (Diesel Particulate Filter) fills up with soot and needs to burn it off into ash. That is called a DPF Regeneration. What it does is inject extra fuel during the exhaust stroke of the engine which then catches fire and burns all that soot off. With the extra heat created from this stuff gets hotter under the hood. Not necessarily the coolant system (that's why your temp gauge shows normal), but the exhaust gets super hot. To protect itself from burning down, it runs both fans at full speed to get some air moving under the hood. Once its done with the regen, the fans will continue to run for another few minutes to bring everything back down to normal temp.

So as you were told, it is perfectly normal. You can expect this to happen approximately every 200-400 miles depending on your mix of city and highway driving. Most of the time, it will happen while you are on the highway and you will never even notice it happening.

There are no lights to let you know a regen is occuring because Vw believes the owners would think something is wrong if a light came on every 200-400 miles. I believe it... LOL

So, if you happen to stop your car when a regen is occuring, its not the end of the world. Just know that next time you drive, it will try to finish its thing. You dont want to interrupt too many consecutive regens as this is how the DPF gets clogged and you will need to take it to the dealer where they MAY be able to force a regen. Sometimes it gets so clogged that it will require replacement.
 

wvmountains

Member
Joined
Oct 27, 2019
Location
Columbia SC
TDI
2012 SEL TDI
Now I know!

Thank you a zillion times over! Now I understand what’s going on every so often. This is the best explanation anyone could ask for. Now I can rest easier.

Happy New Year from SC.
 

740GLE

Top Post Dawg
Joined
Aug 19, 2009
Location
NH
TDI
2015 Passat SEL, 2017 Alltrack SE; BB 2010 Sedan Man; 2012 Passat,
How much did you pay for a '12 with 130K on the clock?
 
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