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Idle creep for reverse not working
Posted: Thu Sep 02, 2021 7:26 pm
by comptonk24
Hello,
I have a Polo GTi 6c 2016 Automatic. Up until today when putting the car into reverse it will creep backwards, however it is suddenly no longer doing this, but still does it to go forward in drive...
Does anyone know the cause of this, and is it possible to fix it myself or should i take it to a garage? I should also note it is due a service, is this something they'd rectify during a service or as an additional charge?
Thanks in advance for the advice/help
Re: Idle creep for reverse not working
Posted: Thu Sep 02, 2021 7:48 pm
by Ricmondo
Has your idle speed dropped?
There are greater mechanical losses using reverse so a small drop in idle speed could prevent creep whilst not affecting first gear creep.
That’s a generic rather than Polo based answer.
Re: Idle creep for reverse not working
Posted: Thu Sep 02, 2021 7:59 pm
by comptonk24
Ricmondo wrote: Thu Sep 02, 2021 7:48 pm
Has your idle speed dropped?
There are greater mechanical losses using reverse so a small drop in idle speed could prevent creep whilst not affecting first gear creep.
That’s a generic rather than Polo based answer.
Sorry not sure what you mean, do you mean the idle speed when going forward? if so I believe it has slowed slightly... Any idea what the 'greater mechanical losses' could be?
Re: Idle creep for reverse not working
Posted: Thu Sep 02, 2021 11:40 pm
by Ricmondo
Idle speed. The rpm that the engine idles at in neutral ie without any load.
Mechanical losses are greater in reverse as it involves additional gears to reverse the direction of the output.
Extra gears mean more friction for the engine to overcome.
It may require more revs to pull away in reverse than going forward so the ‘creep point’ will be higher.
You may get a clue from tachometer readings.
As I said this is a generic answer but I did check on a DSG Polo today and it does need more power to move backward than forward so if the engine at idle is running too slowly it may be reluctant to creep backwards.
On the other hand it might be something completely different but I always start at the simple end.
Re: Idle creep for reverse not working
Posted: Fri Sep 03, 2021 7:24 am
by comptonk24
Ricmondo wrote: Thu Sep 02, 2021 11:40 pm
Idle speed. The rpm that the engine idles at in neutral ie without any load.
Mechanical losses are greater in reverse as it involves additional gears to reverse the direction of the output.
Extra gears mean more friction for the engine to overcome.
It may require more revs to pull away in reverse than going forward so the ‘creep point’ will be higher.
You may get a clue from tachometer readings.
As I said this is a generic answer but I did check on a DSG Polo today and it does need more power to move backward than forward so if the engine at idle is running too slowly it may be reluctant to creep backwards.
On the other hand it might be something completely different but I always start at the simple end.
Thanks, I drove it this morning, and i think idle revs are now lower than before (just under 1000), after driving the car around and then parking it up, it will now creep in reverse. However in normal drive it is now jolting when changing gear, if i put it in Sport mode it seems to be changing gear fine.
Do you know if this is anything to do with the engine mapping/ECU (not sure on correct term) and is it something they would do under a normal service or something that would be an additional cost?
Thanks for your help
Re: Idle creep for reverse not working
Posted: Fri Sep 03, 2021 4:50 pm
by Ricmondo
I’m not sure it could be so many things but a competent VW garage should sort it out at a service.
Hopefully one of the more VW specific forum members will know if there is a simple way to adjust the idle speed. Before cars were taken over by mutant computer processors it was just the tweak of a screw, goodness knows what complications there are now!
I’m glad to have been of some help.