Hi have a 12 plate 1.6tdi that the revs sit at 1100rpm when at idle. Sometimes its 1000 and randomly its 1200 rpm I have been trying to monitor it and it seems to do this until the temp gets to 90 and then rpm eventually drops to normal 850/900rpm. Seems to be at 1100rpm for a good while before dropping. Car does seem to take a while to reach 90 degrees. All my previous other octavias didn't do this. Just wondering if this is normal. It has  been -3c so I am hoping being a diesel 1.6 and due to the cold weather its taking longer to warm up. Electric fan was coming on after engine switch off when at correct temp which I thought may be a failed DPF regen but thats stopped now its got colder. The fan not coming on might be pure coincidence. Car seems fine otherwise (apart from needing a service) with no fault codes or warning lights.

Alasdair

It is normal if the battery capacity is low. Cold temperatures also affect this.

In winter if you have the screen heater, lights and other large loads on then the 1100 rpm idle is used to ensure there is still positive charge going into the battery when the engine is idling. Reverts to 700 rpm when the battery is near fully recharged - about 15 minutes on cold days and/or if the car has not been used for a while. 

10 hours ago, pikpilot said:

It is normal if the battery capacity is low. Cold temperatures also affect this.

In winter if you have the screen heater, lights and other large loads on then the 1100 rpm idle is used to ensure there is still positive charge going into the battery when the engine is idling. Reverts to 700 rpm when the battery is near fully recharged - about 15 minutes on cold days and/or if the car has not been used for a while. 

Many thanks. All before have been  older 1.9tdi and didn't do it noticeably. Makes sense as this car is newer and has more electrics etc. Maybe the battery is getting a bit weak. Will put it on overnight charge and see if it helps. Seems to take at least 20mins to warm up and revs to drop most days especially when its below freezing and car is getting used for only two 5-10 mile journeys most days. Glad its norrmal. I was thinking it might be a idle sensor problem etc. Seem to be having a run of work needing done on my cars and my sons (bearings,clutch,ball joints and thats just the start of the list, and yesterday his needed a new battery so dont need anything else at the moment. 

Alasdair

2 hours ago, Alasdair1 said:

Seems to take at least 20mins to warm up

That is normal on short slow runs and cold days on this efficient diesel. If you set the heater outlet to the central dash vents, you get warmish air before the tenperature gauge needle climbs off the stop.

 

Only had the car a few months as reckoned the old 1.9tdi was past getting an MOT without a lot of work. Did notice that the heaters seem to work as said before temp starts rising. The 1.9tdi seemed to warm up faster although before I sorned it it was struggled to get to temp probably due to bad thermostat. As long as its normal I am happy.

Alasdair