Hello, while approaching to speed bump using brake slightly and rolling over bump in D2, slowly passing the bump and hitting gas normally can feel like grind noise from gearbox? RPMs are cca. 1k or lower sometimes depends how hard foot is on the brake. It is hard to explain this way but seems like brake/acc timing play role here and have got feeling like rpm doesn't match speed in certain situation.. anyone experienced something similar, coasting over speed bumps and hitting gas pedal are best example for me to describe my situation.?

'Coasting is a mode where the DSG comes out of gear. Goes back in if you touch the accelerator or brake.

Are you just rolling on off the accelerator but still in D2 not just D?

Do you use the brake and accelerator at the same time. 2 feet not just 1 foot used?

30 minutes ago, Ootohere said:

'Coasting is a mode where the DSG comes out of gear. Goes back in if you touch the accelerator or brake.

Are you just rolling on off the accelerator but still in D2 not just D?

Do you use the brake and accelerator at the same time. 2 feet not just 1 foot used?

Ye sorry, coasting was bad term to use.. Rolling in D2, slightly braking to slow down over bump, releasing the brake and start to gas, using 1 foot only ofc. Seems like engine still braking in moment when Im trying to hit gas pedal. If I roll over a bit further and press gas pedal everything is right but im too "slow" for car behind me. Seems It is about timing between engine braking and my foot on gas pedal..

I think that might be just the way the gearbox behaves. Try knocking it into sport and see it react a lot quicker. I tend to do this when coming to junctions if I may not come to a complete stop so I can move off quickly

Yes could be normal, just curious if anyone feel the same about certain situation

Just wondering if the start stop could be activating. It does have an annoying habit of stopping the engine while you are still rolling forwards, then you press the glass just as it’s stopping and it takes a moment to sort itself out.

@nicknorman Start stop is off

Now i think i understand when it happens.

But, the GRINDING NOISE noise sounds like an issue.

Not wanting to turn a issue into a crisis but something is not right someplace.

So maybe tell us about the car like, how many miles / km done.

@Ootohere Superb 11/2018 2.0 140kw 116k km

Coming up for the VW Guideline for a Service of the DQ381.

?

Has it been done early / already?

EDIT.

I see you have had problems / faults, so there is likely why now GRINDING>

Edited 16 March, 20251 yr by Ootohere

Yes had common mechatronic problem with K2 sensor, but that should not be related to grind nose for 1sec in certain situation imo since 1 sec noise been present before mcu repair

Edited 16 March, 20251 yr by ile7

No it should not.

But you have a grinding noise and should not, so no idea if Clutches / Flywheel or something else is the issue / cause of that.

Sorry no idea, close inspection underneath the car is all i can think of. Noises come from some source.

IS YOUR CAR FWD ONLY, no HALDEX, no propshaft to the rear? So coupling.

Edited 16 March, 20251 yr by Ootohere

FWD only, will try sporty drive, this way gearbox should response faster

Approaching speed bumps differently or in S might make some difference, but that does not resolve why there was a GRINDING noise.

Turning the radio up resolves faults for many, or at least they do not hear things that might concern them/

Agree that if the noise is grinding then something is happening that shouldn’t be.

Hahah sure thing about radio 🤣

Red light is great example too, while approaching to red which turns to green im D2 full low RPMs speed is under 10 km/h ( gearbox in slowing down "mode" about to stop ) if release brake and instantly move to gas can hear insec grind but if braking and slowly move to gas there is no sound, If let car a bit free roll between braking and accelerating if you know what I mean

Just a minor point here, the car will only coast if it is "ECO" mode or "Individual" where "ECO" has been selected along with other settings and when coasting the gear indicator will show just "E" or otherwise it will display "E2", assuming your car has the DCC system, otherwise the only way to actually coast is by knocking the transmission into neutral.

Could the grinding possibly be coming from the brakes actually sticking a little bit and thus slow in releasing themselves?

Edited 16 March, 20251 yr by Graham Butcher

@Graham Butcher coasting term was my mistake.. sorry will change the title.

What you mean sticking? Clutch or?

2 hours ago, ile7 said:

@Graham Butcher coasting term was my mistake.. sorry will change the title.

What you mean sticking? Clutch or?

Ooer, just noticed that I never finished it, no I meant brakes may be a little slow in releasing.

Edited 16 March, 20251 yr by Graham Butcher

Don't think calipers are wrong..

I think you got too many variables mixing up ... try some experiments.

For example:

• start stop is great but not for the case you are mentioning, or in heavy but not stand-still traffic. The constant stop and go is not kind on some parts, and is annoying. I use SS by default "on", but often I turn it off in such cases, same as the autohold. This way you can control better the car's behaviour, car can't "see" around you the way you are. Set SS to "off" as a test, and drive in the same situations without the engine cutting out and restart, and see what happens.

• Samewise, the DSG has a mind of its own when gearing down/resuming from either start-stop of near idle conditions, neverming coasting. In parallel with the above and/or separated, put the DSG on "manual" and remove another variable.

• LAst but not least, to make sure are not the brakes, you can simulate the same situation in a slow-speed to near-still condition, without the speed bump as an additional variable.

Last but not least, not my intention to sound patronizing or wanting to teach grandma to suck eggs, but is not advisable to apply brakes, or keep applying them, when suspension is on a stressed condition, being a pothole, a speed bump, or any other similar condition. I am not talking emergency braking, just on the normal driving. This is a way to add stress to a number of components, best avoided.

Last but not least, I noticed not only FL cars go "eco" also in Normal mode when light driving is in use, and also you can bring the car out of "coasting" by tapping the left (downshift) paddle. This does not slow down the car as tapping the brakes, merely inserts back the gear it was in before de coasting, allowing to control road speed by engine braking.

It took me a while to understand this, I am not so fond of coasting in some conditions...sometimes is better the engine to brake, but unfortunately coasting is not really "selectable". Pity.

@leolito SS is off, will try in manual mode simulate situation... Could be something around chassis but didn't notice any other noises. Will look a bit further maybe someone has similar "problem"

Hmm, did you say that it happens on speed bumps? It could be suspension related, I notice that on some speed bumps mine also makes some weird noises at times.

Not only bumps, red light example too I wrote above.. should be deffo around gearbox something

Edited 17 March, 20251 yr by ile7

13 hours ago, leolito said:

I think you got too many variables mixing up ... try some experiments.

For example:

• start stop is great but not for the case you are mentioning, or in heavy but not stand-still traffic. The constant stop and go is not kind on some parts, and is annoying. I use SS by default "on", but often I turn it off in such cases, same as the autohold. This way you can control better the car's behaviour, car can't "see" around you the way you are. Set SS to "off" as a test, and drive in the same situations without the engine cutting out and restart, and see what happens.

• Samewise, the DSG has a mind of its own when gearing down/resuming from either start-stop of near idle conditions, neverming coasting. In parallel with the above and/or separated, put the DSG on "manual" and remove another variable.

• LAst but not least, to make sure are not the brakes, you can simulate the same situation in a slow-speed to near-still condition, without the speed bump as an additional variable.

Last but not least, not my intention to sound patronizing or wanting to teach grandma to suck eggs, but is not advisable to apply brakes, or keep applying them, when suspension is on a stressed condition, being a pothole, a speed bump, or any other similar condition. I am not talking emergency braking, just on the normal driving. This is a way to add stress to a number of components, best avoided.

Last but not least, I noticed not only FL cars go "eco" also in Normal mode when light driving is in use, and also you can bring the car out of "coasting" by tapping the left (downshift) paddle. This does not slow down the car as tapping the brakes, merely inserts back the gear it was in before de coasting, allowing to control road speed by engine braking.

It took me a while to understand this, I am not so fond of coasting in some conditions...sometimes is better the engine to brake, but unfortunately coasting is not really "selectable". Pity.

Regarding FL coasting in Normal mode, I found this very irritating. But it can be turned off permanently with VCDS - I did it soon after buying!