



It is a very strange noise, quite low frequency and happens only for a short time; about a second.



If i hold the car at a certain boost it doesnt lengthen the grumble.






Could this be turbo blades rubbing against the housing




I was also thinking that it might be the dump valve, maybe im slightly venting to atmos and recirc at the same time




Basicaly i dont have a clue and would like to find the problem rather than wait for something to fail.


Anyone have any thoughts

Thanks.
