9G Tronic holding low gears too long

[Benz17]

The issue is back, and it seems to happen every time I fill up my tank. Feel like just chucking this car in the bin!

Didn’t you have an appointment with the dealer for this issue?

 

[ShaunDas87]

Didn’t you have an appointment with the dealer for this issue?

I did, but at that point the gears had started behaving- typical! I have another appointment next week, hopefully the gears don't make me look like a pleb this time ffs

 

[rf065]

I find with mine that if you drive with larger throttle openings it hangs on to gears longer, if you drive gently it changes up much sooner.

 

[OneForTheRoad]

I find with mine that if you drive with larger throttle openings it hangs on to gears longer, if you drive gently it changes up much sooner.

Good call , I hit on this in post 12 . It's maybe time for a reset and drive like miss daisy for a few days ,op.

 

[ShaunDas87]

I find with mine that if you drive with larger throttle openings it hangs on to gears longer, if you drive gently it changes up much sooner.

I can literally use a feather but thregears will still still hold and not change, even in Eco. It does shift perfectly until 5th gear, then holds 5th for ages. If I'm going above 60mph it never changes out of 7th into 8th or 9th, I could be doing 80mph in 7th gear unless I change it manually

 

[w212dcaf]

I can literally use a feather but thregears will still still hold and not change, even in Eco. It does shift perfectly until 5th gear, then holds 5th for ages. If I'm going above 60mph it never changes out of 7th into 8th or 9th, I could be doing 80mph in 7th gear unless I change it manually

I know this might sound daft, but Mercedes are early adopters of petrol particulate filters (like DPFs). What is a petrol particulate filter and how does it work?

Not sure on age of your vehicle (I think you said but now can’t see it while writing this!!)

In my diesel with 9G, I get normal operations and changing up gears really early. Then with a few trips (and not many) of local town driving and no motorways, it poos itself a little and starts holding the gears higher (about 2000 rpm) to get the exhaust temp up to help clear the filter and do its thing.

It can do this across a few journeys until it calculates it’s burnt enough crap, then goes back to normal behaviour. Can normally smell it and hear the ticking of hot metal under the car if I end the journey while it’s doing this.

Perhaps taking it for a long blast at a constant-ish 50+ mph run might help it go through the cycles it needs to?!

Then again, this is all conjecture and might be donkey twaddle!!

 

[w212dcaf]

Also meant to say mine does this with normal and non-fluctuating water temperature readings, just holds the gears for a bit, burns stuff, sorts itself out.

 

[ShaunDas87]

I know this might sound daft, but Mercedes are early adopters of petrol particulate filters (like DPFs). What is a petrol particulate filter and how does it work?

Not sure on age of your vehicle (I think you said but now can’t see it while writing this!!)

In my diesel with 9G, I get normal operations and changing up gears really early. Then with a few trips (and not many) of local town driving and no motorways, it poos itself a little and starts holding the gears higher (about 2000 rpm) to get the exhaust temp up to help clear the filter and do its thing.

It can do this across a few journeys until it calculates it’s burnt enough crap, then goes back to normal behaviour. Can normally smell it and hear the ticking of hot metal under the car if I end the journey while it’s doing this.

Perhaps taking it for a long blast at a constant-ish 50+ mph run might help it go through the cycles it needs to?!

Then again, this is all conjecture and might be donkey twaddle!!

It's a 2020 plate and has the 9G tronic engine. Since having it I've never experienced this before. I could do the long blast and see if that helps, but sure as hell won't save me any fuel

 

[ShaunDas87]

It's a 2020 plate and has the 9G tronic engine. Since having it I've never experienced this before. I could do the long blast and see if that helps, but sure as hell won't save me any fuel

Oh and it's petrol

 

[w212dcaf]

Oh and it's petrol

Could it be that it’s taken a few years to build up enough soot and now needs more burns than when squeaky new?!

Noted it’s petrol, but they use particulate filters, too now.

Hopefully the dealer will sort you out. Although if they’re like my local they’ll just lie if they don’t have an answer. Struggling to find a trustworthy main dealer or STAR equipped garage. Hope you have more luck.

 

[ShaunDas87]

Could it be that it’s taken a few years to build up enough soot and now needs more burns than when squeaky new?!

Noted it’s petrol, but they use particulate filters, too now.

Hopefully the dealer will sort you out. Although if they’re like my local they’ll just lie if they don’t have an answer. Struggling to find a trustworthy main dealer or STAR equipped garage. Hope you have more luck.

My dealers are absolute lying shits. I've taken my car in 6 times now for rattles here and there, and even once they said they'd remove the roof lining and reapply it. Did they?? I didn't get a single notification on my phone to tell me my car was unlocked, or even moved from the car park to the garage.

 

[Group Captain]

Italian tune up. Once it's warm red line to 65 on a motorway then maintain high revs for 10 minutes.

 

[OneForTheRoad]

Does the car get up to normal operating temperatures?

Also have you tried resetting the gearbox.