In mid 21 they did change to an electrically operated IWE and no more vacuum. Bet you just had a bad IWE.So I took my car to the dealer and asked him if this can be changed in my 22 timberline.
Unfortunately they say the vacuum is controlled through the TCM and no such valve exists in this model.
Wonder if that is any true.
If so how can the problem be fixed because I still get the noise occasionally.