GLA (ISG Query)

[fourwheels]

As we all know the years roll by (ours that is) so we recently traded in our W205 C250d which we have had from new for a very good 9 years, for a new GLA 200 petrol mild hybrid.

A long history of C’s, E’s, and SLK’s behind us but times change, nevertheless the GLA was a bit of a gamble.

Over the last few weeks it’s proved a delight. Smaller yes but that’s what we wanted.
Comfort and acceleration is impressive for a small engine car.
Will post a photo in due course.

There does seem to be a rattle/clunk noise from somewhere at the back usually on coming to a stop, sometimes I think on accelerating.

Thought to be the boot area but there’s nothing loose in there so I’m beginning to wonder about the Integrated Starter Motor (ISG) which is probably the only part that I don’t fully understand.

Before I challenge the Dealer has anybody with a GLA had similar issues?

Thanks for your help.

 

[markjay]

The ISG combines the alternaor and starter motor providing both functionalities from a single device. It is usually located between the transmission and the engine.

The GLA has a transverse engine at the front, and the ISG will not be in the boot... why do you suspect the ISG to be the cause of the noise?

Also, if the car isn't 4Matic, then there will be no drivetrain at all at the rear. The noise could be coming from the rear suspension, or exhaust mount, or from a loose item in the boot (tyre inflator kit, locking wheelnuts key, etc).

 

[fourwheels]

The ISG combines the alternaor and starter motor providing both functionalities from a single device. It is usually located between the transmission and the engine.

The GLA has a transverse engine at the front, and the ISG will not be in the boot... why do you suspect the ISG to be the cause of the noise?

Also, if the car isn't 4Matic, then there will be no drivetrain at all at the rear. The noise could be coming from the rear suspension, or exhaust mount, or from a loose item in the boot (tyre inflator kit, locking wheelnuts key, etc).

Hi. Thanks for the reply. This noise could be described as either a can or even a wrench socket rolling forward when braking and rolling back possibly when accelerating.
Probably wrong to suspect the ISG (it’s the only bit that I currently don’t understand) so it was a starting point.
Nothing loose in the boot or under the boot floor. We have also removed everything personal from the car.
I know cars always have noises but this car has a lot of kit packed into small places much of it hidden so I think maybe a trip to the dealer is called for. Thanks for your help.

 

[fourwheels]

I was way off track on this. Having just done a 40 mile round trip we realised our rattle/clunk was apparent intermittently for most of the journey.
Popped in to Mercedes dealer and after a quick road trip they diagnosed the reverse camera doing things it shouldn’t so it’s now booked in.
Quite how that relates to the rolling noise we hear I don’t know.
Looking on this forum I see there is history and a thread on the subject. Can’t see how to add a link but the title is.

GLA 200 Reverse Camera calibration every time you start​