Intercooler pipe keeps blowing off on 2.5tdi

Hi, I have an A6 2.5Tdi 2002 and after a recent cambelt service the intercooler pipe behind the foglamp blew off. I was in 5th gear just passing another car on an dual carriageway. A big pop, lots of smoke and no power. I put the pipe back on myself and the servicing garage also rechecked all the pipework due to some strange noises and judders through the car. Basically, if I am at low revs say 1200 and put my foot down the car judders and then smoothes off.

Today however I was joining a dual carriageway and the same thing happened, a judder and before I could back off to chage down a gear the pipe blew off.

I am due to to call the garage in the morning, but what is going on, what is causing the judder and then the pipe to blow off? too much pressure somewhere, something broken in the pipework?

Any advice would be appreciated before I call the garage tomorrow.

Thanks

Alan

Most likely a blocked/jammed VNT mechanism, however the ECU should see the overboost and put the car in limp mode. You will need a diagnostic check to see what fault codes are logged in the memory.

Thanks! If it is a VNT mechanism, can I check it, or even better fix it while the turbo is on the car, or it is a turbo out job? Just waiting for the garage to call me back.

I might be stating the obvious here, but have you checked the condition of the hose, the pipe it attatches to and the clip/band holding it on?