Clattery when cold
Join Date: Feb 2012
Location: United Kingdom
County: Greater London
I have to say I would still suspect the clutch slave cylinder. It's quite possible for a seal to let air in but not leak fluid, losing operating travel. Or it may be a problem at the master cylinder, which will almost certainly have two seals - the primary inner seal leaks fluid, the outer secondary does not. Again there's no external sign of an issue, just lost movement. I have had exactly this fault with brakes (master) on a non-Alfa car and on a motorcycle clutch (slave).
If you find a quick pump of the clutch pedal eases changing gear, that would confirm. By that I mean press the clutch pedal, allow it to quickly return, then immediately press again and change gear, see if it's easier. Because this fault really does sound like clutch drag.
My clutch slave is leaking, although it's working fine. It's only 20k and a couple of years since it was replaced by the previous owner. Obviously it is rubbish, to fail so quickly. There are many mfrs of these cylinders - I found 4 when looking the other day. TRW, Bosch, Sachs, FTE. Price and (very likely) quality vary between £32+VAT and £65+VAT from discount suppliers. I know mine cost £40 from a not particularly cheap supplier, and I suspect I got a POS.