Scirocco Central

keep getting a high idle speed when stationery of 1000rpm had it checked by vw dealer they said its because of high load on battery but im not convinced, doesnt seem to matter what is turned on, has anybody else had this problem?

The idle on mine increases when its doing a DPF regen. Not noticed it at any other time.

It is known...

This is what the dealer is looking at and it is occassionally expected like you remark for the 170PS (& 140PS). Not a fault per say.
I'd give the battery a charge and see if goes away for a while. Could be the battery is not 100%. I've had one on mine since new with suspect charge retention but its not bad enough to fail at VW under warranty. (Yet!)

If you have a volts meter (DVM) to hand...

Measure the battery volts across the terminals while still on the car after about 3 hours from last engine running.

Battery Charged %
100% 12.60+ volts
75% 12.40 volts
50% 12.20 volts
25% 12.00 volts
0% 11.70 volts

If its down towards 50% , then the reaction is genuine, and it points towards a poorer battery or is useage low like me?

Mine keeps sitting at 12.30 volts despite being charged but when tested off car, it won't fail enough to say its goosed. But the Central Electrics/Battery Monitor module keeps complaining about low voltage and checks on the car in VCDS confirm the voltage is low in the controllers. On the alternator/battery, all is as expected.

I would expect it to be more at 12.4/12.5 volts at least. As I would yours when you test it.

C.

Cuprabob wrote:The idle on mine increases when its doing a DPF regen. Not noticed it at any other time.

How often does it regen?

I read somewhere it tries to do it every 700 miles but don't quote me. When it's regenerating you know as you can sense the heat and there is a smell. If you switch off while it's doing it the fans run on for 10mins.

Its VW(USA), but the same as the European Training manual for the CR engine.
TDi 2.0Ltr CRail. Look through pages 56 - 65 for regeneration.


Back to........

greyfox1 wrote:1000rpm had it checked by vw dealer they said its because of high load on battery
has anybody else had this problem?

C.

RW1 wrote:Its VW(USA), but the same as the European Training manual for the CR engine.
TDi 2.0Ltr CRail. Look through pages 56 - 65 for regeneration.

Thanks for the document, interesting reading

RW1 wrote:It is known...

This is what the dealer is looking at and it is occassionally expected like you remark for the 170PS. Not a fault per say.

Diesel 170PS Idle.JPG

I'd give the battery a charge and see if goes away for a while. Could be the battery is not 100%. I've had one on mine since new with suspect charge retention but its not bad enough to fail at VW under warranty. (Yet!)

If you have a volts meter (DVM) to hand...

Measure the battery volts across the terminals while still on the car after about 3 hours from last engine running.

Battery Charged %
100% 12.60+ volts
75% 12.40 volts
50% 12.20 volts
25% 12.00 volts
0% 11.70 volts

If its down towards 50% , then the reaction is genuine, and it points towards a poorer battery or is useage low like me?

Mine keeps sitting at 12.30 volts despite being charged but when tested off car, it won't fail enough to say its goosed. But the Central Electrics/Battery Monitor module keeps complaining about low voltage and checks on the car in VCDS confirm the voltage is low in the controllers. On the alternator/battery, all is as expected.

I would expect it to be more at 12.4/12.5 volts at least. As I would yours when you test it.

C.

Should I expect similar rev ranges on a 1.4 160hp ? Just thinking about that bonging sound on mine. I'm not convinced that the battery is weak and the absence of higher revs would seem to support that.
Just curious raeally

I'm seeing high idling revs every day at the moment, for the first 5 mins of the commute, as it's around freezing. High load initially as you're relying on the glow plugs (or if you don't wait, the engine turns over for about 3 seconds as opposed to one), and then i'm putting the climate control on 18C.

This is nothing to worry about on a VAG TDI when using it in the cold, especially for the first few miles of your journey, just the car trying to supply more recharge to the battery to help it recover from high load use.

This will drop off in the spring and summer, or if we get another few days of unseasonally warm winter weather (8-12C, as we saw a week or so ago).

ZephyR wrote:Should I expect similar rev ranges on a 1.4 160hp ? Just thinking about that bonging sound on mine. I'm not convinced that the battery is weak and the absence of higher revs would seem to support that.
Just curious raeally

No. 160PS doesn't have this idle programme of settings. Only standard idle at ~680rpm.

You've probably got the same as me with useage. Leads to 12.3 volts or even 12.2 volts at the battery but by the time it gets to the Scirocco's Battery Monitor module, it is at 11.60 volts so it sets off the warning that the Battery Monitor is telling the Central Electrics to shed electrical load to preserve what remains of the battery charge. ie. the bong sound is heard. (=time to charge on the trickle charger)

I've started putting mine on the trickle charger for a day (8 hours) once a week since November while its colder and the sound has gone, as has the diagnostics indication, that the bong about to sound. 60 miles a week at 10 by 6 mile trips and 15 min time slices each is not enough to charge the battery to recover from the starter and the low useage combined. Had the same battery charge level indications on my last Mk2 Scirocco daily, particularly in winter.

Mines has had a perminently wired up plug fitted to the battery for a while, which couples up with the charger at the garage door.

C.

Thanks for that Chris.

I also had this problem shortly after I took delivery of my tdi 170, having spoken to my dealer he explained that it is to do with the particulate trap cleaning itself out, you may also notice a few other symptoms, like the car is not as smooth to drive, it's asks for lower gears (e.g asking for 3rd at around 30mph whereas normally it would be happy in 4th), also the cooling fan continues to run after you stop the car and the exhaust gets very hot.

It is the usual fix as with other cars with this system fitted, simply run the car at around 2500 rpm in say 4th gear for about 15 mins, I also find just general driving using a lower gear than normal also does the trick, you'll know it's back to normal when it starts to tick over at the normal rate.

Regards
Martyn