GLA AMG 35 Shuddering when slowing to a stop(Not the brakes!!)

[RobertT]

The last couple of months the car has developed what I would describe a reluctance to disengage the clutch smoothly or at the right time, when slowing to a stop. Sometimes it feels like the engine might actually stall, but it doesn't of course. Unfortunately I'm not a mechanic so I might not be describing it correctly but it reminds me of the time I drove a manual and when you come to a stop but you've been a bit late pushing the clutch in. I've booked it in to be looked at in a couple of weeks but I'm not hopeful. During booking, the Mercedes chap said it's most likely the "shuddering" comes from the brakes but when i said it was more like a clutch/gearbox issue and not brakes he of course gave me that "know it all" look. Suffice it to say I'm not, hence the reason for posting this thread. I'm dreading Mercedes saying it's a car characteristic which tends to be their stock answer to everything when they can't find a solution. Has anybody had the same or similar issue as described? (While at the garage there're also going to look at the windscreen wiper which has a tendancy to hit the driver side windscreen pillar too regularly)

 

[badgx]

Are you getting shuddering through the brake pedal? High or at low speeds?

 

[RobertT]

No I don't feel shuddering on the brake pedal. And I only have it when slowing to a stop, there is no problems when accelerating.

 

[badgx]

Assuming its automatic, I wonder if you are low on transmission fluid? Best to have it checked out and get codes read. Might be something simple?

 

[RobertT]

Yes hopefully it's something simple. It's only done 8000 miles of easy driving so it can't possibly be wear and tear.

 

[davidgibson734]

Hi Robert,
Do you still have the problem ?
I can relate to this, as my 2017 E400 4-Matic 3.0-litre V6 petrol had the following symptoms:-

• Juddering when coasting down to a stop on say the off-ramp of a motorway, invariably followed by a puff of blue smoke out of the exhaust when the power kicks in.
• Excess oil consumption.
• Sometimes the car feels as though it is in too high a gear, with the revs appearing quite low (below 1000rpm) and then I paddle-shift down a gear. I feel it should be shifting down automatically, but it doesn't until I press harder on the accelerator.

My research suggested the answer might be an issue with the Positive Catalyst Ventilation (PCV) Valve, so I got my go-to mechanic to change this and I thought it had done the trick, but I fear the symptoms have started to return after only a few hundred miles.
My local M-B dealership can't offer explanations of the likely cause (they said it could be lots of things) and they don't want to take the car in unless the Engine Management Warning Light comes on at which point the car is in a real mess.
My research into other possible causes will continue and eventually I will get there !
David.

 

[grober]

Assuming the GLA A35 is automatic--- the gearbox is essentially a manual box with twin automated clutches-- sounds as if you might have a problem with one of them? Best get the fault codes read on a Mercedes diagnostic system.

 

[RobertT]

Just an update. Took the car in and of course the Mercedes garage couldn't find a fault. They updated the software and made some adjustment which they said should help with the issue i was experiencing. Unfortunately it hasn't, still getting an occasional clunk when braking to a stop. To me it's like the clutch isn't disengaging properly or at the right time. Still not panicking yet though as the car is still under warranty but it does spoil the driving experience a little. It seems extreme but I hope it gets worse so that Mercedes will have to acknowledge the fault and come up with a solution.