Heater noise on 2000 Silverado when rpm is speed up: No engine codes

Question:

It is starting to get cold and my heater is making a funny noise every time I rev up the engine speed. I tried flushing the coolant system but it did not make any difference. The parts store told me that I need a new heater core but I want to run this by you before buying it.

ATS Advisor:

GM trucks like yours have this problem for a while and this is caused by a strong flow of coolant inside your heater core. To eliminate this, there is a rubber restrictor in the inlet side of the heater hose installed in it. This restrictor or orifice might have broken and must be replaced. Make sure to check this and replace if necessary.

ATS Tip:

While you are doing this, check all your hoses for connections and see that the hoses are not swelling and properly routed away from exhaust. When done, do a pressure test on the coolant to make sure every thing is tight and secure including the elimination of air in the system.(this is discussed in ATS past newsletters).