A flaw in engine mounts that could lead to unwanted vibration will delay the sales launch this month of General Motors Corp.’s new cross/utility vehicles but only temporarily, the auto maker says.

GM recently sent dealerships a “stop sale” notice for the ’07 Saturn Outlook and GMC Acadia after engineers discovered water was getting into the engine mounts of test-fleet vehicles.

If the water freezes, it could cause “undesirable” engine vibration when starting the vehicles, a GM spokeswoman says.

GM already has shipped about 550 Acadias and Outlooks to dealers for the sales launch at the end of this month.

The auto maker now is sending bulletins to the dealerships explaining how to fix the cold-weather defect, which involves drilling holes in the engine mounts to prevent water from collecting.

The same fix is under way at the Lansing Delta (MI) Plant that produces the new models.

The necessary modifications won’t hold up sales by more than a few days, a spokeswoman says.

“We’ve got it all covered now at both ends,” she says, adding the engine-mount flaw did not interrupt production of the new models.