Joined
·
5 Posts
Got a weird problem on my 2006 A150 with Autotronic gearbox over the past few months.
I had the car in to get transmission oil change and brake fluid change at the main MB dealer here. A few days later, I noticed a slight juddering when in slow moving traffic, nothing concrete but just a feeling that the car wasn't running as smoothly. Further, I noticed it happening more often, and did some tests.
It seems the slight juddering I feel through the wheel coincides with the engine revs suddenly increasing by 200rpm for a couple of seconds, then suddenly dropping to the original amount. This can be on a perfect flat surface where I'm deliberately holding the revs constant, i.e. it's not the usual rev increase/decrease you'll see on the autotronic 'box. It seems to not do it at all until the engine temp is fully warmed up. Then this little revs 'blip' starts occuring, but it's approximately every 20seconds. If I've been driving for a while (e.g. 45 mins) the frequency increases to about every 10 seconds.
Weirdly, it doesn't do it at idle, or if sitting in neutral at 2000rpm, for example, however I notice it happening in the 1600-3500rpm range, certainly at the 1800-2000rpm that would be normal revs at a constant 40mph.
The symptom occurs whether in C or S auto setting, or in manual mode.
I had the car into the dealer to get it checked but they could not find any fault (obviously, there are no warning lights on the dash), although speculated 'could be gearbox related'. I just find it odd that it started occuring a few days after getting the gearbox oil changed.
As if to justify their labour time, I had a new firmware update for the transmission applied, with the classic 'tested and all ok now' on the worksheet. Of course, working in IT for 20 years, I *know* that firmware updates are done to fixe SPECIFIC issues, and random 'I'll just update the firmware anyway' fixes rarely fixes anything ;-) Needless to say, the problem still occurs afterwards.
The car is at 86,000 and I am due to sell it anyway, just very concerned about possibilty of 'new gearbox' and obvious impact on future sale price (it's only worth around £3500 on a trade-in anyway).
Anyone have any ideas? It's almost like a sensor somewhere is playing up... I presume autotronic SHOULD have a working lifespan of much more than 86000? The problem has not got worse since it first started occurring.
I had the car in to get transmission oil change and brake fluid change at the main MB dealer here. A few days later, I noticed a slight juddering when in slow moving traffic, nothing concrete but just a feeling that the car wasn't running as smoothly. Further, I noticed it happening more often, and did some tests.
It seems the slight juddering I feel through the wheel coincides with the engine revs suddenly increasing by 200rpm for a couple of seconds, then suddenly dropping to the original amount. This can be on a perfect flat surface where I'm deliberately holding the revs constant, i.e. it's not the usual rev increase/decrease you'll see on the autotronic 'box. It seems to not do it at all until the engine temp is fully warmed up. Then this little revs 'blip' starts occuring, but it's approximately every 20seconds. If I've been driving for a while (e.g. 45 mins) the frequency increases to about every 10 seconds.
Weirdly, it doesn't do it at idle, or if sitting in neutral at 2000rpm, for example, however I notice it happening in the 1600-3500rpm range, certainly at the 1800-2000rpm that would be normal revs at a constant 40mph.
The symptom occurs whether in C or S auto setting, or in manual mode.
I had the car into the dealer to get it checked but they could not find any fault (obviously, there are no warning lights on the dash), although speculated 'could be gearbox related'. I just find it odd that it started occuring a few days after getting the gearbox oil changed.
As if to justify their labour time, I had a new firmware update for the transmission applied, with the classic 'tested and all ok now' on the worksheet. Of course, working in IT for 20 years, I *know* that firmware updates are done to fixe SPECIFIC issues, and random 'I'll just update the firmware anyway' fixes rarely fixes anything ;-) Needless to say, the problem still occurs afterwards.
The car is at 86,000 and I am due to sell it anyway, just very concerned about possibilty of 'new gearbox' and obvious impact on future sale price (it's only worth around £3500 on a trade-in anyway).
Anyone have any ideas? It's almost like a sensor somewhere is playing up... I presume autotronic SHOULD have a working lifespan of much more than 86000? The problem has not got worse since it first started occurring.
