Fan running after shutoff

ChadS99SVT

Veteran Member
Joined
Jul 17, 2012
Location
Parker, CO
TDI
2013 Passat TDI DSG
Is this like a turbo cool down feature. I've only put a few miles on the car but noticed that I turn the car off and the radiator fan continues to run.

Not enough experience yet to determine why or when it will happen.

Can anyone explain? I assume this is normal?
 

whitedog

Veteran Member
Joined
Jul 12, 2004
Location
Bend, Oregon
TDI
2004 Jetta that I fill by myself
Ask your salesman why he didn't teach you about what happens with the regen system and why the fans run.

(BTW, I believe this is the first regen post of the month. Congratulations.)
 
Last edited by a moderator:

compu_85

Gadget Guy
Joined
Sep 29, 2003
Location
Springfield VA
TDI
... None :S
Actually, it might not be a regen... GeekDrew's car seems to do this nearly every shutdown. Kind of like the engine cool off feature my old Audi 5000 had.

-Jason
 

GeekDrew

Veteran Member
Joined
Jan 23, 2008
Location
Columbus, OH, USA
TDI
None
Actually, it might not be a regen... GeekDrew's car seems to do this nearly every shutdown. Kind of like the engine cool off feature my old Audi 5000 had.

-Jason
This. I'm going to ask the dealer about it later this week, but I don't anticipate a response more useful than "herpaderp it's normal".

To be more explicit for ChadS99SVT: All NMS/B7 Passats will occasionally be running fans during dpf regeneration; there is reference to this in the owner's manual, I believe. It's therefore normal to hear fans running if you happen to shut down the car during a regen cycle - so it would be normal to hear them sometimes. My car ('12 Passat TDI SEL Prem), however, runs fans after maybe 75% of my shutdowns. Sometimes they run for just a minute, sometimes for much longer. We're trying to determine whether or not this is normal.
 
Last edited:

VeeDubTDI

Wanderluster, Traveler, TDIClub Enthusiast
Joined
Jul 2, 2000
Location
Springfield, VA
TDI
‘18 Tesla Model 3D+, ‘14 Cadillac ELR, ‘13 Fiat 500e
During a regen, the fans will be running with the engine and continue to run after shutdown. (You shouldn't do this, by the way - let it finish before shutting off the engine).

Drew's car will start the fans after shutdown even with no regen in progress before the shutdown (verified on ScanGauge).
 

ChadS99SVT

Veteran Member
Joined
Jul 17, 2012
Location
Parker, CO
TDI
2013 Passat TDI DSG
During a regen, the fans will be running with the engine and continue to run after shutdown. (You shouldn't do this, by the way - let it finish before shutting off the engine).

Drew's car will start the fans after shutdown even with no regen in progress before the shutdown (verified on ScanGauge).
Thanks for the comments guys. I knew I was bound to get jabbed for not using the "search" or touching on a hot noob subject, but I'm fairly new to turbo cars and never had a diesel nor a VW.

I'm not blaming my dealer. I wanted to get out of there and it was late etc. we went over some of the unique features and I went on my way (my choice).

Now that some of you are talking about this It does sound a little familiar while trolling this forum for a while. can someone elaborate on what the "Regen" exactly is?

Why do I not want to turn the car off? and how am I supposed to know if there is regen going on? It seems like so far it's always been happening every time I have shut the car off (like 4 times so far lol).

on a side note I had my first commute this morning and car was great! :cool:
 

VeeDubTDI

Wanderluster, Traveler, TDIClub Enthusiast
Joined
Jul 2, 2000
Location
Springfield, VA
TDI
‘18 Tesla Model 3D+, ‘14 Cadillac ELR, ‘13 Fiat 500e
Sounds like your car is behaving just like Drew's car.

A "regen" is an exhaust regeneration, in which the engine uses elevated idle and "post injection" to superheat the exhaust system to burn off soot that accumulates in the DPF (diesel particulate filter). Regens occur approximately once every 500 miles, but can be more or less often depending on your commute and driving style.

If you notice an elevated idle and the cooling fans on HIGH when you park, your car is most likely in the middle of a regen. I recommend letting this process finish (can take up to 5 minutes) before shutting off the engine. Exhaust temperatures are in the 1100°F range during a regen and shutting off the engine can cause oil to coke inside of the turbo's center cartridge. I have hypothesized that interrupted regens are the cause of premature turbo failures on previous generation commonrail cars (2009+).

I recommend buying a ScanGaugeII and adding an XGauge for Cat #1 temperature sensor, which is the pre-turbo EGT (exhaust gas temperature) sensor. Normal operating range is 400 - 900°F while driving. If you notice EGTs hovering around 1100°F, you know you're in the middle of a regen.

www.scangauge.com

http://www.youtube.com/watch?v=FQznjhZgteA <-- video of a regen happening on our Passat - note the ScanGaugeII
 
Last edited:

oilhammer

Certified Volkswagen Nut & Vendor
Joined
Dec 11, 2001
Location
outside St Louis, MO
TDI
There are just too many to list....
So, is this the first one of the month? Does each model section get its own allotment, or is it a group thing? :p
 

Roshermoore

Veteran Member
Joined
Jan 5, 2009
Location
East Texas
TDI
2009 JSW DSG sunroof
Is this like a turbo cool down feature. I've only put a few miles on the car but noticed that I turn the car off and the radiator fan continues to run.
Not enough experience yet to determine why or when it will happen.
Can anyone explain? I assume this is normal?

:) Scroll down to to the very bottom of this page. There you'll see links to five threads all dealing with this subject. Read all five of these and you'll know all you need about running fans and regeneration.
 

ChadS99SVT

Veteran Member
Joined
Jul 17, 2012
Location
Parker, CO
TDI
2013 Passat TDI DSG
:) Scroll down to to the very bottom of this page. There you'll see links to five threads all dealing with this subject. Read all five of these and you'll know all you need about running fans and regeneration.
lol awesome trick! thanks I will do that :D
 

Hoosierine

Member
Joined
May 6, 2012
Location
Ann Arbor, MI
TDI
2012 Passat TDI SEL Premium
My fans also seem to run at least half the time, especially with how hot it has been.

Is there any other way to know if it is in regen besides higher idle or temps if I don't have a scangauge yet. i thought an icon was suppose to light up on the dash?
 

VeeDubTDI

Wanderluster, Traveler, TDIClub Enthusiast
Joined
Jul 2, 2000
Location
Springfield, VA
TDI
‘18 Tesla Model 3D+, ‘14 Cadillac ELR, ‘13 Fiat 500e
Negative. It's basically undetectable to the operator unless you know what to look for. The light only comes on if there is a problem.
 

gergg

Veteran Member
Joined
Feb 6, 2011
Location
Georgia
TDI
2012 Passat TDI 6M
I hardly ever had the fan running after turning off the engine, most of my runs were 30+ miles so maybe this had something to do with it.
 

ChadS99SVT

Veteran Member
Joined
Jul 17, 2012
Location
Parker, CO
TDI
2013 Passat TDI DSG
Our fans don't do after-run either.
I think it was the computer cycling being a new car. just getting the first session under control.

after reading the research I get it and I have been watching/listening and all has been good nothing since those first few starts.

just another sign these cars prefer to go the distance and not short trips. :D
 

dubStrom

Veteran Member
Joined
Aug 6, 2007
Location
Kansas City Missouri
TDI
2003 A4 Jetta (sold), 2010 JSW (sold), 2013 Passat 6MT traded for 2014 JSW with 6MT-TOTALED in November 2016, 2003 ALH 5MT conversion (sold), wheezing 2015 GSW/DSG and a new 2021 Tacoma Access Cab 4x4 p'up
During a regen, the fans will be running with the engine and continue to run after shutdown. (You shouldn't do this, by the way - let it finish before shutting off the engine).

Drew's car will start the fans after shutdown even with no regen in progress before the shutdown (verified on ScanGauge).
I noticed this during a new Jetta test drive the other day. Just the radiator fans spinning at low speed, NOT the ferocious sound with burning cinder odor. It's just the cooling system. New "feature" I guess.
 

FormerOwner

Veteran Member
Joined
Apr 16, 2006
Location
Alabama
TDI
2013 Passat TDI SE 6spd; Former Owner 02 MkIV wagon
When I drive long trips... no fans...

When I drive short trips... always fans... but they stay on for about 2-3 minutes MAX... No smell at all!

Drive > worry < !!!
 
Last edited:
Top