I have noticed the same, when they do occur the duration is much shorter than my 2010 Jetta.I was wondering if anyone has monitored their active regens on the 2012 Passat? Based strictly on seat of the pants observation, it seems like this Passat has way fewer active regens than my 2011 Golf did.
Urea allows the exhaust to run at a higher temp which creates more NOx but the Urea takes care of this. Soot is vaporized quicker at the higher exhaust temps. You will also notice the cold engine temps come up much faster in the Passat.I wonder if it has something to do with the urea? It requires less heat to activate a regen so it would make sense it takes less time.
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When the fans are running it means you interrupted a regen.I have noticed a few times where the fans have been running full blast after I parked the car and turned it off. They did this in pretty cool weather with relaxed driving. Is this a regen? If not, how can you tell a regen is occurring?
You will notice the rpm needle hovering round 1000 while idling.how can you tell a regen is occurring?
Also, if you're using a ScanGuage, which shows you real coolant temp, coolant temp rises from normal 198-202 to 206-210. At least, that's what mine shows...ditto for my 09 JSW.You will notice the rpm needle hovering round 1000 while idling.
LMAO! Okay Darrell, now describe the DEF system with a similar metaphor.Regen's work similar to the trash can in your kitchen. Trash (soot) is collected filling to the point emptying (Regen) is needed. Your wife (DPF sensor) tells you (ECM) the trash is getting to the point it needs to go out. Now for some reason you start to empty the trash but you get interrupted. The trash can continues to fill until you get the chance to empty it. The amount of trash and how fast its collected can vary based on a variety of activities.
The downstream post DPF exhaust is like the water in your pool. In order to thoroughly clean the water (post DPF exhaust) you add chlorine (AdBlue or the generic equivalent).LMAO! Okay Darrell, now describe the DEF system with a similar metaphor.
Haha, I understand what I regen is, I just wasn't sure how to tell if they were occurring or not. I have lots of experience with diesel engines, but not any in owning and operating them. All of my experience is the in the design and development of the engines.When the fans are running it means you interrupted a regen.
Regen's work similar to the trash can in your kitchen. Trash (soot) is collected filling to the point emptying (Regen) is needed. Your wife (DPF sensor) tells you (ECM) the trash is getting to the point it needs to go out. Now for some reason you start to empty the trash but you get interrupted. The trash can continues to fill until you get the chance to empty it. The amount of trash and how fast its collected can vary based on a variety of activities.
I had an interrupted regen once after I parked and turned off the engine, fan under the hood running like crazy with loud noise, after a few minutes, didn't know what happened, I restarted the engine and the loud sound was gone, hopefully it didn't do much damage..[/QUOTE]
"Interrupting a regen" does NO damage of any kind. When the car is moving, during a regen, the flow of air through the radiator is usually sufficient to cool the engine. If the vehicle stops moving, the heat rises, triggering the high-speed fans.
As soon as the engine is turned off, any regen in progress is stopped. However, the residual heat might require the fans to continue to run. Therefore, if the fans are still running after the engine is turned off, it is ONLY to dissipate residual heat...the regen has stopped.
An interrupted regen will re-start, once the engine is re-started, and comes up to a temp hot enough to trigger the regen.
In traffic, when I hear a regen in progress (fans running, raised coolant temps, RPMs near 1k) I will put the car in neutral, and keep the engine at 2k rpm, to provide sufficient exhaust flow to assist the regen. This may not be necessary, but I like to think the added exhaust flow keeps things cleaner.
FYI, this scenario (active regen while not moving) has only occurred a dozen or so times in 50k miles. All the other regens must have occurred while at speed (over 2k rpm).
The newer, possibly cleaner, 2012 TDI might require fewer regens, but not because of the DEF. The addition of DEF has nothing to do with the DPF, and the number of regens required.
The downstream post DPF exhaust is like the water in your pool. In order to thoroughly clean the water (post DPF exhaust) you add chlorine (AdBlue or the generic equivalent).
Well this analogy fails since Adblue is Urea which is what Urine breaks down into so you can't equate it to chlorine.wait, so you pee in the pool to make it clean?
The analogy was about treatment and conversion processes not the specific molecular or biological components of the process.Well this analogy fails since Adblue is Urea which is what Urine breaks down into so you can't equate it to chlorine.
Chlorine does nothing for the pee. The urea levels keep climbing, biological processes not Chlorine break it down. The Chlorine just kills and then the shocking level of Chlorine oxidize "burn up" the organic dead matter. Urine is actually sterile, it is what gets pickup on the way from the kidneys that is an issue. TMI.
That doesn't sound too good, if I were smelling something in the cabin like that I would certainly have it checked out, especially considering your throat burning experience.Does the regen cycle create an odor? I smell a slight kind of thickly sweet engine odor at times. Seems worse now (16K miles) than when the car was new. I usually drive 40 miles at a time for my normal commute. Doesn't seem normal. My throat was burning on a long drive recently (all-day). Is it something I should have the dealer look at, or will it go away?
I have been paying CLOSE attention and I have not noticed anything to indicate them. Perhaps they are so short lived that you don't really notice it until you stop.Previous 2.0 CR TDIs do an active regen every 300-400 miles, depending on how the car is driven. I would assume this 2.0l TDI is probably the same, so 400 miles seems about right. I just returned from a 2600 mile road trip, and never noticed a regen, so they must have occured while cruising.
This is the only time I notice mine.I have been paying CLOSE attention and I have not noticed anything to indicate them. Perhaps they are so short lived that you don't really notice it until you stop.