noise from turbo
 

Hi everyone
this may be a silly post but I am slightly worried about the noise coming from my turbo/compressor when the engine is turned of after a short but not aggressive 5 minute run

I have just bought my98 uk impreza. I have recently done a full flush of the coolant as the car has been stood in a barn for over a year it recently passed its mot only needing new D's & P's and a wing mirror now i am waiting for the end of the month to tax it so in the mean time I have been cleaning it up on the inside and under the bonnet.

anyway every few days I start it up l& et the engine water temp get up to quarter
then take it for a short run down were it is kept (private road and land) a few minuets later I pull up but only after driving in 4th @ 30mhp for a minuet or two then take the key out but the turbo timer kicks in for 30 secs

when I've lifted the bonnet I can hear a faint bubbling sound at first I thought it might be the head bubbling like the head gasket has gone or going as of the new coolant change but

1 I have a good lot of heat coming from the heaters
2 no loss of coolant
3 no overheating
4 no bubbling from expansion tank or headers
5 the coolant lowers when engine is revved and raises when revvs dropped
6 no milky water or oil in the engine or coolant
7 no excessive steam from exhaust

any way today I took it for a run like above I popped the bonnet and I am 99% sure its the turbo bubbling and gargling then stopped surly this is not a good sign :cry:

do you thinks the turbo is on its way out?
the car has covered 106k miles &! I am the 10th owner (it had 4 owners within its first 40k)

thanks for looking
Jim

I forgot to mention when boosting the turbo seems louder than the last impreza I had.
the first time I drove her I thought I had a pressure leak somewhere because of the noise