159 Gearbox 'slap'
I wonder if anyone can help me?... Although this problem is quite hard to describe:
I have an Alfa 159 Ti 2.4JTDm. It is 4 years old and in it's life it has suffered endless episodes of engine hesitation which, even after a cylinder head replacement under warranty (not convinced why Alfa thought it was this) has never fully disappeared. But the nature of the hesitation certainly has not been the same over this time. The one thing common to all my hesitation events has been that it always occurs when you're hovvering between acceleration and deceleration.
Recently, I have started to develop a new theory and wonder whether the hesitation that I still have is not an engine management issue or some problem with the EGR, but maybe instead from gearbox 'slap'...
What I mean by this is the idea that within the gearbox there might be quite a finite 'zone' of non-cog contact as cogs transition between accelarating (the cogs leading edge being driven by the engine) and decelarating (the cogs trailing edge being arrested by the slowing car). So my thought is that the hesitation is in fact simply the gearbox "taking up the slack" as it moves between these two states. Is that possible or understandable? Or am I going mad?
I also now have quite an interesting noise coming, I think, from my gearbox when I go between acceleration and deceleration and vice versa, i.e. if you are pootling along in a low gear (e.g. 2nd), then gently accelerate then decelerate then acelerate, etc, I get this odd squeek appearing on each transition. I have convinced myself that it is not the suspension because I now hear it for a very brief moment when starting the car as well. I'm beginning to get nervous and wonder if anyone has the slightest idea if my explanation vaguely fits an issue that is known or might need attention.
Any help or thoughts would be appreciated.