Hi, I've noticed occasionally my Monte 105TDI ticks over at 1000rpm rather than the usual 750rpm even when its warmed up!

Is this normal ? I've wondered if its to do with the DPF Regenaration!?

Cheers,

It can either do this when there is a high electrical load and it ramps up the idle to run the alternator faster or as you say could well be regenerating.

Has it happened when you have done a few short journeys? If so it could be the DPF or the electrical load.

Phil

Even though I don't have a diesel, it does sound like DPF regen to me from what I've read... Does the engine have a slightly different "tone" to it as well?

the engine does sound normal, I'll mention it when i take it in for first service, I'm sure my dealer will have all the answers!!

Is it the alternator charging the battery as you have extra load demand.

Lights, heated screen, music on etc.

Battery would discharge without being re-charged or meeting the demand, which is what the alternator does.

(short journeys in winter & people get flat batteries)

High CCA as the engine is started depletes the battery, the alternator recharges.

a vRS starts easy, a diesel takes a bit more oomph from the battery.

ie Engine RPM picks up with the extra work/load. Then all is well.

george

Like we have to explain to our customers at work, make sure everything is switched off in the car, then switch items on and the revs will increase as you put more load upon the vehicle, e.g heaters, demisters, lights, radio and so on.

it revs at 1000rpm with nothing switched on and after i've done some miles too!

Sounds like an active DPF regeneration to me, my Yeti does it quite regularly in the winter, as the cold is not letting the engine get warm enough to do it passively.

TP

I had a tdi 90 as a courtesy car recently and noticed something similar when I was stuck in traffic on a road with a slight downward slope. Traffic was barely moving (constant stop-start) so I was just letting go of the brake pedal to move the car forward for like a second or two, until the cars in front stopped again. What I saw happening was that, when stationary, it sat at around 750-800 rpm, then when I let go of the brake pedal, as soon as the speedometer moved off the zero, it was idling at 1000 rpm. Once I braked again, as soon as the car became stationary, it went back down to 750-800 rpm. It would just do the same thing over and over, without fail. No gear selected and clutch was out all along. The car was pretty much new with about 600 miles on the clock, so I assumed this was normal.

Is that what's happening with your car by any chance, Charles?

Sounds like a regen to me as well. Mine does for a few minutes then goes back to an idle of 750rpm for a thousand odd miles

Edited 7 December, 201213 yr by threadbear

Like the guys are saying...it sounds normal and it most likely connected to a regen. But if it isn't that it may be the fly by wire throttle needs recalibrating. If this goes out of sync it produces results similar to the ones you are describing. Reasons for it going out of sync are: faulty throttle pedal unit, battery has been disconnected recently and a glitch has prevented proper syncronisation, ECU needs a reboot from a diag machine as it's forgotten about the throttle parameters. There are other things too but just mentioned it as a way forward if it doesn't settle down.

Yes, it's the car doing a DPF regeneration, had this for the first time on my car last night, idled at 1000rpm and the exhaust note was slightly different too - nothing to worry about unless the light appears on the dashboard.

When I'm regenerating, the stop/start doesn't work and the RPM jumps up to about 950RPM from 750RPM.

Have had a alternator replaced on my 2016 1.6 ti Octavia and now thr car constantly revs to a 1000rpm hot or cold after sitting at normal idling 20 seconds later it moves up to 1000rpm ,then I drive off next stop its at normal idling 20 seconds later 1000rpm this does this constantly I use her as a taxi and it well looked after this puzzles me is it a battery fault 

 

On 04/04/2019 at 14:52, David-f said:

Have had a alternator replaced on my 2016 1.6 ti Octavia and now thr car constantly revs to a 1000rpm hot or cold after sitting at normal idling 20 seconds later it moves up to 1000rpm ,then I drive off next stop its at normal idling 20 seconds later 1000rpm this does this constantly I use her as a taxi and it well looked after this puzzles me is it a battery fault 

 

First while only 4 years old if the car is started many times a day the battery could well be shot.

 

Second was the alternator fitted a new or exchange genuine VAG part direct from VAG or a 3rd party item new or recon?

If the latter maybe the output signals to the ECU are different hence the ECU thinks the battery is low so stepping up the idle speed. If a recon maybe the main fault was repaired but a second fault in the control module still exists, which a 3rd party may not be able to test for. Also if 3rd party while physically identical or close enough to fit is it not 100% compatible.

As an example years ago when Rover in the 218 / 418 had the Peugeot engine the Peugeot alternator would fit and charge fine but the tacho did not work.

Has anyone solved this problem?

 

my 1.6tdi has the same problem 

 

750rpm until warm then 1000rpm

 

turn engine off for 10mins 

 

750rpm.. at this point i can rev the engine and it drops back to 750

 

however as soon as the car is in motion/driven a few meters its back to 1000rpm

 

 

 

 

 

 

@Skodacrazy  Is it actually a problem, or just you have a Euro 5 TDI and it is winter time?

Or are you not in the UK and someplace warmer? 

4 minutes ago, Ootohere said:

@Skodacrazy  Is it actually a problem, or just you have a Euro 5 TDI and it is winter time?

Or are you not in the UK and someplace warmer? 

2014 rapid TDI 1.6

 

yes UK

 

My boost control valve is constantly clicking loud throughout the rpm all times 

Its already sounds like a tractor at 750rpm lol 

 

Edited 12 December, 20241 yr by Skodacrazy

Sorry i mis-read. did not read properly. 

i thought it was another high rpm too long post  Really i am a muppet. 

I’ve just took it for a drive without a heavy right foot

 

the boost valve was nowhere near as noisy and the rpm returned to 750 after warmed up 

 

guessing its the boost control valve

 

it also regenerate the dpf with the orange light whether this had any impact idk 

 

I would have thought it would create fault codes for this solenoid?