Hello,

 

I've noticed the last few weeks that my Octavia's 2.0TDi's idle speed is up around 1000 - 1100 most (but not all) of the time, I've got Aircon, heaters, AC etc all turned off and even when car is warmed up it will still do it.

 

I generally use the car twice a day for a good 35 / 40 mins and sometimes up to an hour so it should have plenty of opportunity to complete a DPF cycle

 

An alarming thing is that with the idle so high, when your approach a junction and drop down a gear then lift the clutch and expect to cruise / slow down it gives a noticeable pull and actually accelerates away if on the flat or a (very) slight downhill gradient and you need to hit the brakes instead of just coasting to the junction.

 

It's still got 18 months on the warranty so I can take it back in to the dealership, but wanted to check if anyone else has the problem... is it related to the cold weather recently (although it will do it when temps are up 6 or 7 degrees and the car is well warmed up)

 

Thanks

 

 

Its most likely a DPF regen, on my old mk6 GTD it used to do it at the most in appropriate times like at the end of a 40 minute commute. I expect the car takes longer to get up to DPF regen temperature. If its doing it all the time, then to the dealer but if it dissapears then its most likely doing what its supposed to.

The idle speed is around 1000rpm if the vehicle is moving & also if you lift the clutch pedal partially just before the bite point.

It is a way to assist the driver pulling away & prevent stalling.

It you come to a complete stop, does it go back to 750rpm?

 

It could be an issue with the clutch pedal sensor not reading fully depressed?

 

There are also many other reasons why the idle speed can be increased when the engine is hot.

AC, alternator load, to improve cooling if engine is very hot & DPF regeneration.

If it was DPF regen it shouldnt happen all the time, perhaps only once a week & there are other tell tale signs of regen like the fan running at 100%.

Your driving profile should be more than enough to complete a regen in one go without repeated attempts.

and reading your post again, if the idle speed is >1000rpm it is not regen or the other things.

1100rpm should normally only come due to engine temperature being cold.

If you look in the maxidot what is the oïl temperature & what is the coolant temperature on the dial?

Hello, thanks for replies

 

To answer a few points - no when I stop altogether (handbrake on) it still stays at 1100 rather than dropping down to 750.

 

Temperature is up normal around 90 degrees, never seen it running hot, and it will be up at 1100 even after only a few minutes when the car is still warming up sometimes.

 

The next few days are forecast to be relatively mild at 10 degrees so my plan is to see if it still does it then (i.e. not related to really cold weather), and if so take it in to the dealer.

 

 

Throttle position sensor faulty (It's part of the complete pedal assembly.) Could also be due to a split vacuum hose. Test the brake servo using the normal method. Ignition off, pump brake pedal to deplete the servo vacuum, pedal should go rock hard. Keep pedal depressed, and start engine, pedal should sink an inch or two.

Mine does this as well. The clutch pedal has to be fully depressed to the footwell and it drops down to 750 rpm. Otherwise only slightly off the floor and the tick over rises to 1000rpm. Does seem a little strange but apparently it is an anti stall process. In 10000 miles I havent stalled my car....

 

 

Thanks all,

 

I will try the brake test and also the clutch when I drive home tonight, and see how it goes over the next few days now the temperature has risen to a relatively balmy 10 degrees.

 

Cheers

 

When you first start the car with a cold engine, it is normal that the idle speed can be higher.

The idle speed will be increased the colder it is outside.

As the coolant temperature rises the idle speed should gradually decrease until the engine is warm (maybe over 30-40°C) when it should idle at 750rpm.

 

If the engine coolant is 90° on the maxidot gauge & it is still at 1100rpm then there is a problem somewhere with the clutch, accelerator pedal or one of the engine temperature sensors.

@IanPorter did you get to the bottom of this mate?