Strange one this, My car  63 plate MKIII Octavia Tdi, Vrs, 21500 miles on the clock.

 

Been out in the car today and as I came to a Stand the Revs were at about 1K, usual signs it's doing a region, drove the car the long way  home and came to a stand and the revs were about 750, regen complete I thought.

 

However when I stopped at the next junction the revs were 750 Then slowly rose to 1K again. Every time you come to a stop the revs are at 750 then rise slowly to 1K  Came home, stopped the car turned the Engine off, left it a couple on minutes restarted the Engine revs at 750 then once again thy rose to 1K.  No Lights on the dash, car runs fine

 

I'ts although the car wants to keep doing regens but there's no hot smell, mpg is the same and the fans don't continue after the engine has been turned off.

 

 

Any Ideas Folks

 

 

Thanks 

 

AG

Edited 19 July, 20169 yr by Auric Goldfinger

I'm new to VAG engines, but I know that the BMW's won't perform regens if there are ANY fault codes at all showing.

No idea if these are the same, but worth having a quick read of the codes anyway.

Weather related?

 

Mine was at 1k rpm at tickover all ever time I stopped but wasn't doing a regen, was 32C outside and I have the Climate set to 19C and in Auto...

Weather related?

 

Mine was at 1k rpm at tickover all ever time I stopped but wasn't doing a regen, was 32C outside and I have the Climate set to 19C and in Auto...

 

Tell you what Neily, you might be right. Just been out for a drive and all seems Ok.  Climate set at 16c in Auto and all seems to be ok.

 

Thanks Neily, good call.  I'll keep my eye on it

Edited 19 July, 20169 yr by Auric Goldfinger

Yep, mine's behaving likewise. I guess the aircon is working harder and the engine is compensating somehow?

Yep probably the aircon. Its working a lot harder during this little heatwave.

I always run it in auto mode, but now my mpg has dropped to 45mpg from 52mpg, so you can tell the compressor is working all the time.

Well you learn something everyday.

 

Thanks Guys, 

As already stated in hot weather the aircon has to work harder, so the revs go up to handle the extra load. So that will be about one day per year here in Scotland, 

Yes, its the aircon, I can confirm as well.

 

I would still wanted a visual sign in the dashboard whenever the car is doing a actual regen though so I can maybe go for a drive instead of turning the engine off after parking and listening the stupid vents going crazy.

There are many reasons (asside from regen) that engine revs are increased.

As you've figured out running AC typically increases idle to improve AC compressor performance (especially on cars with smaller engines & petrols with low torque at idle).

Releasing the clutch slightly inceases the revs as the engine prepares for a pull-away.

When the vehicle is moving about a few kph (can't remember if the Octavia does this or whether it is my BMW).

Engine cooling to increase the flow of fresh air & fluids through the engine etc

 

I never really understand why people want to know a regen is happening (apart from perhaps technical curiosity).

If I were VW I would decrease the fan speed at stopping to be much less noticeable as this will make people much less worried about it.

 

 

I never really understand why people want to know a regen is happening (apart from perhaps technical curiosity).

If I were VW I would decrease the fan speed at stopping to be much less noticeable as this will make people much less worried about it.

 

Me either, the car is quite capable of dealing with regens without help.

I've noticed on my new one that the fans are much quieter if I turn it off during a regen.

I never really understand why people want to know a regen is happening (apart from perhaps technical curiosity).

If I were VW I would decrease the fan speed at stopping to be much less noticeable as this will make people much less worried about it.

Having a tuned engine with dpf in a long term can get you worried since more soot is being generated on daily basis.

Just parked my car and guess what, the car is doing its thing.. Unless here is another case in which the vents are working and the car is not doing a regen.

If the engine (oïl, coolant, turbo air temperature) is hot its normal for the fans to run-on for a few minutes when the engine is stopped.

This was standard on many cars before DPFs were introduced & is present on petrol equivelants as well.

 

The Octavia is the first car I've had where the fans run at 100% when stopped.

Usually they would run much lower so that the driver "didn't notice" the sound & think there is a problem as seem to be the case with many people worrying about regeneration.

Edited 20 July, 20169 yr by Gabbo

Possible, but I still dont know.

 

I noticed during hot summer days sometimes the revs (when in neutral) stay just a little below 1k, while sometimes they are right at 1k.

I would say when regen is happening there will be a fixed increase in rpm (so should be exactly 1000rpm).

 

When the engine is too hot (the same like when it is very cold at startup) the engine speed will increase based on the temperature

e.g. 200rpm when its very very hot which will decrease slowly as the températures decrease.