Not a problem, but curiosity really. Sometimes when I start my petrol 1.4 TSi it idles straight away at 800 rpm. Other times it starts off at 1200 rpm, then drops back after less than a minute to 800 rpm. The strange thing is, the fast idle seems to happen more often when the engine isn't completely cold, e.g. 5 or 6 hours after stopping, and less often after an overnight stop. There is no apparent correlation with outside temperature, lately its done it at about 15 degrees and just once I was treated to a cooling fan cutting in for 3 seconds. I have found it best to wait for the idle to drop, as moving off straight away can provoke kangaroo jerks for a second or two. Is this some fiendish software controlled catalyst pre-heat or coolant circulation scheme ? Theories anyone ?

It really wanted to be a diesel, so is having phantom passive revens?

I don't know if this is good or bad news but I've just realised my 1.2 TSI Elegance seems to do the same thing... higher revs just for a short time then drops to around 800 rpm but not every time. I'll have to pay more attention and see if it's also linked to "not quite cold" like yours.

Still, the car's not yet a month old and I took out the extra warranty so if its going to go wrong it's got four years and 11 months before I need to get too concerned.

Mine does this as well. I have to be careful when reversing out of the garage at first start as the higher revs make the car go backwards too fast in the DSG drive "R" mode, and I often have to brake to avoid taking off the wing mirrors if parked too close to the wall

I now have some more information about fast idling with the TSi.  Dealer "A" told me the fast idle probably happened because it sensed the battery voltage was low.  Considering the car is only a year old and its the middle of summer this seemed entirely unlikely.  Dealer "B" told me it was to get the heater working quickly.  Or maybe the air conditioning.   A detailed search on the internet provided a third and most likely explanation which I have pieced together below, this applies to the 1.4 TSi CAXA engine but may also apply to the 1.2 TSi.

 

After starting, the Engine Management Unit looks at various temperature and other sensors and decides if it would be safe/worthwhile to pre-heat the exhaust catalyst to reduce emissions.  Rather like Goldilocks and the porridge, if things are too cold or too hot the answer is no. If the answer is yes, the idling revs are increased to around 1300 and the ignition timing is considerably retarded.  The late ignition means that the gases coming past the exhaust valves are still burning hotly, which raises the temperature of the catalyst more quickly than would happen otherwise. It also makes the exhaust sound wierdly burbly like a diesel. After about a minute, the revs are gradually dropped to normal and the odd noise stops. Unlike older VAG engines, there doesn't appear to be a separate whining air pump for the warm-up cycle, possibly (my theory) because direct injection can be leaned off immediately after starting and there is therefore less carbon monoxide needing extra oxygen to burn.

 

In principle the car is still drivable while this is going on, but in practice it would seem that the engine management has some difficulty coping with all possible drving conditions and jerky running and spitting are not unknown for the first few hundred yards, especially if you go above 2000 rpm. I imagine this would be "interesting" if you have DSG.  From now on I am going to confine myself to shutting the garage doors, putting on the seatbelt, twiddling the radio and slow speed manoeuvres until it has "done its stuff".

Edited 2 July, 201313 yr by Austin 7

My good lady has just bought a new Hyundai i20 and this does the same, a trip to the dealers and she was told it was to do with the set up for reduction of emissions.

Thats put my mind at ease because my 59 plate tsi does it too.

It also happens on my 2012 Octavia 2.0tsi vrs. Only now and again though

Same with my 1.4 TSi - thanks for such a comprehensive explanation :-)

My TDi does this also,it ref's up to 1000 rpm for some time and drops down to 800 rpm, so it is not only TSi related

My fabia TSI does this on occasions. But i don,t think it is for anything quite so clever as "emmisions" or temperatures. This is a fault developing. And i think is is something "sticking". The reason --- It DIDN'T do it for the first 2 years i had the car. Why would it wait 2 years before being such a sophisticated engine? The dealer couldn't give a reason.

Mine does this aswell, it's perfectly normal i've been told

Just to add , If this happens with mine , I have found that turning off the engine and then restarting , seems to "reset" it back to its normal idle speed

Good evening to you all. My first contribution here on Briskoda as I have only owned my Octavia for a few months. But I have been having the same issue and its been bugging me for weeks so I would like to share something I noticed when starting first thing in the morning.

 

Sometimes, more often than not, I would sit in the car, press the clutch down, take it out of the 1st gear into neutral then start the car (some of you thinking why is he saying all of this but bare with me its important to the story). When the car is started in this order of events the revs will remain at around 1200rpm for around a minute then gradually drop to 750-800. However, if I start the car with clutch down (obviously) but still in gear and then once the engine is running take it out of gear the revs drop to 750-800 straight away.

 

I don't know if anyone else noticed this and if you haven't try and see if yours does the same. The question still remains as to "why" does it do that. It does not seem normal to me and part of me is thinking that something is on the way out. Would be great to hear your views on this. Thanks. 

 

P.S. My car is a 1.4 tsi 2011 Octavia Elegance with just under 40,000 miles. I am also quite certain it wasn't doing that from the beginning.

Good evening to you all. My first contribution here on Briskoda as I have only owned my Octavia for a few months. But I have been having the same issue and its been bugging me for weeks so I would like to share something I noticed when starting first thing in the morning.

 

Sometimes, more often than not, I would sit in the car, press the clutch down, take it out of the 1st gear into neutral then start the car (some of you thinking why is he saying all of this but bare with me its important to the story). When the car is started in this order of events the revs will remain at around 1200rpm for around a minute then gradually drop to 750-800. However, if I start the car with clutch down (obviously) but still in gear and then once the engine is running take it out of gear the revs drop to 750-800 straight away.

 

I don't know if anyone else noticed this and if you haven't try and see if yours does the same. The question still remains as to "why" does it do that. It does not seem normal to me and part of me is thinking that something is on the way out. Would be great to hear your views on this. Thanks. 

 

P.S. My car is a 1.4 tsi 2011 Octavia Elegance with just under 40,000 miles. I am also quite certain it wasn't doing that from the beginning.

 

 

I always leave the car in neutral (manual one) when parked however, whenever I start the car I also have the same thing, it idles around 1200 rpm for around 30 secs (when the weather is nice around 20-25 Celsius but the interesting thing is when i start it during the cold mornings it keeps the rev around 900 rpm - like the cases being told here.

It's perfectly normal. It's called "cold start". My former Audi A3 1.4 TFSI did exactly the same.