[kugo_93]

Originally Posted by GrandTourer

Is this going to be an issue going forward? Has anyone experienced the same? Lastly, do you think a workshop visit is required?

I drive the rapid tdi dsg, I have observed this exact same behaviour as well , that's just something to do with the dsg logic, maybe shock sensors prevent any shifts to preserve the shifting mechanism is what I guess, there is no need to visit the showroom for this.

[GrandTourer]

Originally Posted by kugo_93

I drive the rapid tdi dsg, I have observed this exact same behaviour as well , that's just something to do with the dsg logic, maybe shock sensors prevent any shifts to preserve the shifting mechanism is what I guess, there is no need to visit the showroom for this.

Originally Posted by JoshMachine

I, personally, haven't experienced these scenarios actually, however the situation of the gearbox presumably remaining stuck in D1 / not upshifting relatively quickly, maybe attributed to the out-of-turn slow down (due to the pothole or the rough road patch) followed by immediate demand to upshift.

Thanks for your inputs.
I have been observing this for some time now. Maybe I'll have it checked in the next service.

Yes, I got the EW. Wasn't going to risk it with DSG.

[swissknife]

I read somewhere that the following actions resets the DSG. I have tried it and it does feel different. No apprehensive shifting.

1. Floor the "A" pedal
2. Insert the key move it one notch (do not start the engine)
3. Hold it in the same position for 30 seconds.
4. Turn the key to the "off" position
5. Release the "A" pedal and floor it again
6. Turn the key one notch (do not start the engine)
7. Wait for 30 seconds
8. Release the "A" pedal
9. Start the car
10. Feel the difference.

[Maverick444]

I have a 2012 Superb TSI with the DQ200. I recently got my mechatronic unit changed under goodwill warranty for the second time and replaced the clutch kit as well. Is it wise to consider a change in transmission oil from synthetic to mineral for longevity of the box?

I ensure I always engage neutral when sitting in traffic, do not stress the box by depressing the brake pedal while in Drive mode (to inch forward in traffic) and despite all my efforts to protect the gearbox from bad driving habits, I felt a jerk last week in the transmission.

If the switch allows me to keep the car for longer, I would like to proactively get it done, as usual Skoda dealers are clueless about such hacks. Any thoughts on the matter?

[adimicra]

This thread is wonderful though I could not understand all the technical details.

I am considering to buy the Skoda Octavia 1.8 TSI. Given the issues with the DQ200, I am hesitating to put 25 lakhs on this car. I am actually fine with manual transmission but the 1.8 TSI is not available in manual transmission. I understand that DSG issues can be mitigated to an extent by using manual/tiptronic mode in high traffic conditions.

SO, if I drive the car as a manual using the tiptronic mode mostly, can the DSG issues be avoided? What happens when I am in 5th gear in tiptronic mode and I press the brake and don't downshift, will the DSG automatically downshift? If not, there is a chance of the car stalling if I am unable to downshift manually within time and there is no manual clutch?

[roadie_swift]

Hi, first up, great choice, go for it. It's a lovely car. I'm still getting to know mine, been just about 2.5k km with her.

Originally Posted by adimicra

If not, there is a chance of the car stalling if I am unable to downshift manually within time and there is no manual clutch?

No, this doesn't happen. If you are in M and the revs drop off, the DSG will shift to D and automatically downshift as needed, so there's no danger of the car stalling. In fact I've noticed that if you are cruising in M and there hasn't been any input from your side (through the paddle shifters or the stick in tiptronic), after a set amount of time the DSG will shift back into D. I'm not sure how much time, but seems less than a minute. Other Octy owners might chip in to confirm this.

Cheers,
R_S

[adimicra]

Thanks for the clarification.
Can someone please verify if the below assumption is correct -
" I understand that DSG issues can be mitigated to an extent by using manual/tiptronic mode in high traffic conditions."

Also, I read somewhere that when brake pedal is fully pressed, the DSG switches the car to N automatically or do we have to do it manually?

[swissknife]

Originally Posted by roadie_swift

so there's no danger of the car stalling. In fact I've noticed that if you are cruising in M and there hasn't been any input from your side (through the paddle shifters or the stick in tiptronic), after a set amount of time the DSG will shift back into D. I'm not sure how much time, but seems less than a minute. Other Octy owners might chip in to confirm this.

Cheers,
R_S

Yes, it does down shift automatically when the revs drop, but it does not move to "D". It stays in "M" in my car.

[roadie_swift]

Originally Posted by adimicra

Thanks for the clarification.
Can someone please verify if the below assumption is correct -
" I understand that DSG issues can be mitigated to an extent by using manual/tiptronic mode in high traffic conditions."

Also, I read somewhere that when brake pedal is fully pressed, the DSG switches the car to N automatically or do we have to do it manually?

1. Yes, it definitely can be mitigated since the DSG issues are mainly around the mechatronic module, which is affected by heat, which is generated when the gearbox has to crawl in stop and go traffic. The heat is made worse when the DSG - in the interest of fuel economy - shifts to 2nd gear as soon as the car is moving. Putting it in M stops this from happening, since the car remains in 1st much longer and helps slightly reduce the load and resultant heat.

2. No this is not true. Even with the brake pedal fully pressed the DSG remains in D. To get into N you need to physically move the stick. This is also highly recommended, especially when the stop time (red light, for example) is likely to exceed 20 seconds. I personally shift to N for anything that looks longer than a 10s wait.

Hope this helps.

Cheers,
R_S

Originally Posted by swissknife

Yes, it does down shift automatically when the revs drop, but it does not move to "D". It stays in "M" in my car.

Yes, that's correct. My bad, I meant just to say it downshifts automatically.

It doesn't shift to D if the stick has been moved to tiptronic, but it does move to D automatically if Manual mode has been engaged by using the peddle shifters.


Cheers,
R_S

[Jeroen]

Originally Posted by roadie_swift

1. Yes, it definitely can be mitigated since the DSG issues are mainly around the mechatronic module, which is affected by heat, which is generated when the gearbox has to crawl in stop and go traffic. The heat is made worse when the DSG - in the interest of fuel economy - shifts to 2nd gear as soon as the car is moving. Putting it in M stops this from happening, since the car remains in 1st much longer and helps slightly reduce the load and resultant heat.

Not sure I quite follow this
Why is this heat worse in second gear? Less fluid circulating due to lower RPM? Or something different?
What do you mean the load is reduced in 1st gear?

Thanks,
Jeroen

[Chethan B G]

Originally Posted by Jeroen

Why is this heat worse in second gear? Less fluid circulating due to lower RPM? Or something different?

As the shift from 1st to 2nd happens very quickly, it can result in un-necessary lugging, which in-turn can result in clutch slip/wear and over heat.

Originally Posted by Jeroen

What do you mean the load is reduced in 1st gear?

Lower load due to higher gear ratio in the first gear.


Please correct me if I am wrong.

[Mortis]

Has anyone tried pasting on some additional heatsinks on the DSG gearbox if there is space to do so ? Higher surface are will improve the cooling a bit

[Jeroen]

I am not expert in gearboxes and certainly not on DSG, but here are my thoughts

Originally Posted by Chethan B G

As the shift from 1st to 2nd happens very quickly, it can result in un-necessary lugging, which in-turn can result in clutch slip/wear and over heat.

If a clutch, on a manual box or a DSG starts slipping due to lugging, there is something wrong with the clutch. If you put your foot down on the accelerator your clutch will have to deal with a whole lot more torque, for a longer period of time, than some engine lugging.

A clutch that slips unintentional needs replacing or redesigining in my mind.

Originally Posted by Chethan B G

Lower load due to higher gear ratio in the first gear.

We need to a bit more specific what you mean with load and how load generates heat. Lets keep it really simple: Engine, DSG, driveshaft, wheels

To drive at a steady speed (say 20 or 30 km/h) the wheels need to turn at a constant speed, which means the output shaft of the DSG turns at a constant speed too, irrespective of actual gear selected. So the DSG output shaft delivers at a given constant RPM a certain constant HP and Torgue.

With a different gear selected the input side of the DSG (engine), the ratio of HP/Torgue/RPM differs of course.

Inside the DSG irrespective of gear selected, a lot of parts will be turning at various rpm, irrespective of the gear selected. At a constant vehicle speed, in general lower gears (e.g. 1st) means most inner parts will be turning faster than at a higher gear (e.g. 2nd)

Heat inside the DSG is generated by friction in the various bearings and by the fluid being displaced between the teeth of the engaged gears. For both heat generation is a function of the RPM and pressure (load) on the oil between the engaged gear wheels. And then there is probably some heat being generated by everything turning and churning up the fluid. And some other stuff too. But lets forget about that for the sake of simplicity.

Going from 1st to 2nd, means a drop in RPM on the engine and the input shaft of the DSG. Which in order to keep everything constant on the other hand means a slightly higher torque, but a lower RPM on the various 2nd gear bits.

In theory that might generate some more heat, but then again, most inner bits of the DSG will be turning at a lower RPM, thus less friction, less churning of transmission fluid, thus less heat produced.

Or vice versa, dropping from 2nd into 1st. higher rpm, lower torque in the input shaft etc. etc

Also, at speeds from 20 km/h drive wind along the DSC starts to become efficient in helping to cool the DSG. Ambient air temperature has some, but not a very large effect.

Heat build up in a gear box, is just another way of describing and quantifying efficiency. I.e. the loss of power between in- and output. In a gearbox the only way it manifests itself is in heat build up.

What you are saying is that the DSG efficiency is less at higher gears, especially at lower rpm in a particular gear selected. I do not know if that is true?

Obviously the exact same logic would apply if you force a downshift from 4 to 3. In fact the effect is likely to more pronounced, because at higher vehicle speeds we will have higher RPM, HP, torque in general.

The above is just a very simple theoretical approach on how I ran this through my mind. Many variables, but my gut feeling is that you would be hard pressed to actually measure any such effects for real.

I might be wrong of course. I must admit I have never actually seen an opened up DSG. So my understanding of how it all works is more based on what I have seen/found on the Internet.

Jeroen

[Sutripta]

^^^
The main source of heat generation will be a slipping clutch. If it is a wet one, it will be a pretty effective heating source for everything the oil touches.
I think this will require some theories to be tweaked.

Regards
Sutripta

[Chethan B G]

Originally Posted by Sutripta

The main source of heat generation will be a slipping clutch.

Yes.

Originally Posted by Sutripta

If it is a wet one, it will be a pretty effective heating source for everything the oil touches.

At least heat generated will dissipate. Component layout can be accordingly managed. In case of the dry clutch, it is even worse.