Electric Fan,.....running too much?

Joined
Mar 15, 2007
Location
Kentucky
TDI
2004 Jetta
I have a 2013 SE model, that has around 1200 miles on it and on a couple of different ocassions, the electric fans run 4-5 minutes after shutting the engine off.

Keep in mind, the ambient temperature at the time this occured, was between 80-85 degrees,.....and the car had not been drove for an extended period (less than 4 miles), when this happened.

This doesen't seem to be normal. :confused:

Anyone else have this issue?
 

Lightflyer1

Top Post Dawg
Joined
Sep 13, 2005
Location
Round Rock, Texas
TDI
2015 Beetle tdi dsg
Yep normal dpf regen. This filter catches soot particles and every so often as you have found it burns them off. A little extra fuel is injected and the temps get up to 1200 to 1300 F to burn the soot in the filter off to ash. When this happens the fans will be running at high speed until it completes and cools off to normal temps. When this is happening some of us continue to drive until it finishes as shutting it off in the middle of one and not letting it complete is deemed not good. Really need some kind of gauges though to be able to see it happening (Torque app on android phone or Scangauge). Read up here on this. Happens every 200 to 600 miles and lasts for 5 to 10 minutes at speed.
 

RDC98tdi

Veteran Member
Joined
Sep 14, 2009
Location
Louisville KY
TDI
'13 Jetta 6MT Prem / (RIP) '98 Jetta 5MT [280k+mi]
I have the Jetta, but have similar experiences.

First, it doesn't necessarily have to be a regen that is occurring. I use the Torque App and wait to shut my car off when the E(xhaust) G(as) T(emps) are below 450 Fahrenheit. But, even at those temps (definitely not a regen) then my fans have spun after shutting the engine down. It's usually after my 80 mile commute home in the 85+ heat and the coolant temperature is around 210+ (I drive pretty fast). So even though the EGTs aren't high, the fan still runs, especially if you have had the A/C on.

A way to tell if your DPF is in a regen cycle is to watch the RPMs. When my car was just started and not up to full operating temps, it idles about 830 RPM. When it is fully warmed, it's 800 +/- 5 RPMs (unless the car is moving, then its around 900). During a regen, the car should idle around 950~1000 RPM and the fans will most likely be on high. If you come to a stop and notice that the car is idling fast AND the fans are running fast, I would wait a few minutes and wait for the regen to complete, as this should keep the DPF cleaner and allow the exhaust to cool down so it doesn't cook your engine compartment and underside!

Edit -- of course being two different cars with two (slightly different) engines, the temps and idle RPMs could be slightly different for a Passat. I don't have the fancy AdBlue exhaust treatment :D
 
Last edited:

hysterwv

Veteran Member
Joined
Aug 10, 2006
Location
WV, OH, KY
I have the Jetta, but have similar experiences.

First, it doesn't necessarily have to be a regen that is occurring. I use the Torque App and wait to shut my car off when the E(xhaust) G(as) T(emps) are below 450 Fahrenheit. But, even at those temps (definitely not a regen) then my fans have spun after shutting the engine down. It's usually after my 80 mile commute home in the 85+ heat and the coolant temperature is around 210+ (I drive pretty fast). So even though the EGTs aren't high, the fan still runs, especially if you have had the A/C on.

A way to tell if your DPF is in a regen cycle is to watch the RPMs. When my car was just started and not up to full operating temps, it idles about 830 RPM. When it is fully warmed, it's 800 +/- 5 RPMs (unless the car is moving, then its around 900). During a regen, the car should idle around 950~1000 RPM and the fans will most likely be on high. If you come to a stop and notice that the car is idling fast AND the fans are running fast, I would wait a few minutes and wait for the regen to complete, as this should keep the DPF cleaner and allow the exhaust to cool down so it doesn't cook your engine compartment and underside!

Edit -- of course being two different cars with two (slightly different) engines, the temps and idle RPMs could be slightly different for a Passat. I don't have the fancy AdBlue exhaust treatment :D
I'm with you on this. It's NOT a regen every time. My driving is almost exclusively highway trips, with a short trip being 40 miles. Oftentimes they're 200+ miles. During the summer months my fan stays on almost every time I turn the car off. It's not doing a regen, just cooling down.
 

Sigforty

Veteran Member
Joined
Apr 27, 2013
Location
Prairieville, LA
TDI
2012 Passat w/DSG
Ac will cause the fans to run. It happens a lot to me down here in Louisiana. I just look at the RPMs and if they are at 950-1000 it is in a regen.
 

JSWTDI09

Top Post Dawg
Joined
Jan 31, 2009
Location
Las Vegas, Nevada
TDI
2009 JSW TDI (gone but not forgotten)
Your fans will always run under several circumstances:
1) A DPF regeneration is in progress (or recently was)
2) Coolant temperature is over a certain threshold
3) AC is on

Number 1 and 2 will often keep the fans running for a while after you turn off the car.

Have Fun!

Don
 

VeeDubTDI

Wanderluster, Traveler, TDIClub Enthusiast
Joined
Jul 2, 2000
Location
Springfield, VA
TDI
‘18 Tesla Model 3D+, ‘14 Cadillac ELR, ‘13 Fiat 500e
Aside from the regen after-run of the fans, the fans run almost any time the engine is running (when it isn't winter). Remember that the cooling fans not only provide cooling for the engine radiator, but also for the AC condenser and the intercooler radiator. If you watch fan speed in VCDS, you will see that it increases any time you lay into the accelerator (example: passing someone) to maintain desired intake air temperature.
 
Last edited:

BPofMD

Veteran Member
Joined
Mar 12, 2013
Location
Maryland
TDI
2012 Passat SE
Wish someone would figure out what the code is for that fan speed so we could watch it in our Scan Gauge. If it shows up in the VCDS, we SHOULD be able to see it in the SG.
 

SilverMerkur

Well-known member
Joined
Feb 4, 2013
Location
Austin/Round Rock, TX
TDI
Now: 2014 Passat TDI 6M; Then: 2009 Jetta TDI 6M - Loyal Edition
One thing I've noticed on my car, it appears that when it is in regen, the shift indicator is typically telling me to shift down one gear from where it normally sits otherwise. I would not have expected the logic determining shifts points would have been smart enough to include regen events where we want the RPMs to be a bit higher. Pretty cool.....
 

psd1

Veteran Member
Joined
Aug 4, 2011
Location
OR
TDI
2006 Jetta 2013 Passat SE 6Man
I am experiencing less regens as the miles go on, anyone else noticing this?
 

RDC98tdi

Veteran Member
Joined
Sep 14, 2009
Location
Louisville KY
TDI
'13 Jetta 6MT Prem / (RIP) '98 Jetta 5MT [280k+mi]
PSD1, I think it has something to do with the engine being broken in and burning more efficiently (less soot). Have you notice your MPGs going up?
 

psd1

Veteran Member
Joined
Aug 4, 2011
Location
OR
TDI
2006 Jetta 2013 Passat SE 6Man
PSD1, I think it has something to do with the engine being broken in and burning more efficiently (less soot). Have you notice your MPGs going up?
MPG has always been good, not sure I am seeing an increase because of break in, but I am happy with it!
 
Top