Loss of power pt2

[hoj]

A week or so ago I asked about a problem I had with my V70 D5 and loss of power
Was it the turbo? was it a fuel filter? was it something else? I opted for a filter and all seemed ok …….until yesterday
Joining the motorway from a slip road I got into 4th gear doing about 60 changed to 5th put my foot down and nothing again no lights no noises no nothing just no more acceleration/power the car ran great when idling at lights or junctions etc and I could get up to around 30/40 mph for 15 miles to home but still no acceleration as such
This morning started first time as usual and all back to normal again
Baffled now any ideas anyone
Thanks

[Thassos]

I too recently had a very similar problem on my D5, couldnt find much initially, but i would suggest taking a look at the intercooler... not easy to see, as its the centre of the 3 radiator sandwich, but if you remove the plastic tray under the rads (just 2 10mm bolts) and unclip, you should be able to see the bottom of the rad stacks, take off the flat plastic sheet on the bottom edge (has some not so great fir tree clips x3) and then youll see it, if you have any sludge like black oil showing, or the edge is bowed like a banana then you have prob got a leaking intercooler.. performance will have dropped to awful, and boost pressure gone, if you have an elm327 bluetooth plus something like torque, youll prob be able to see if your getting boost pressure..