If the turbine whistles, it may be due to a leak or damage to the impeller. Refurbished turbines are often as good as new ones if they are made well. A new one is a safer but more expensive choice.

For your Mercedes, consider Mercedes turbos from the reconditioned turbo series. This will help restore performance with minimal costs. Such options are in demand among Jaguar and Audi owners, especially for Jaguar turbos and Audi turbos, where reliability is important.