350Z V6-3.5L (VQ35HR) (2007)
c. Use blunt pinch clamps to pinch the heater core inlet and outlet hoses; this will stop the water flow through the heater core.
d. Start the engine and check for the noise; gradually increase engine RPM to 3500.
NOTE:
Do not run the engine for more the 5 minutes with the heater hoses pinched.
^
If the noise is gone, this bulletin applies, go to step 2, below.
^
If the noise is still there, this bulletin does not apply; return to ASIST and the Service Manual for further diagnostic and repair information.
2. "Back-Flush" the heater core as follows:
a. Follow Service Manual procedures (section CO) to drain the cooling system.