Rattle or Buzz Noise from the Instrument Panel (Install Tie Strap on Heater Hoses)

Some customers may comment on a rattle or buzz noise coming from the instrument panel area. The concern may be more noticeable with the transmission in drive and engine speed between 900 and 1500 rpm.

The heater core pipes may be rattling against the inside of the HVAC (heating, ventilation and air conditioning) case.

Technicians are to install a plastic tie strap around the hoses going to the heater core using the following procedure:

1. Open the hood and install fender covers.
2. Remove the coolant reservoir from it's mounting bracket and reposition it to permit access to the heater hoses.
3. Remove the vacuum hose to the power brake booster and reposition it.



4. Install a plastic tie strap around the heater hoses at the heater core in the engine compartment and tighten it to put a slight pressure on the hoses. Make sure the tie strap is installed close to the hose clamps so that it will apply pressure to the heater core pipes inside the heater hoses. If the tie strap is installed too far away from the hose clamps, sufficient pressure will not be applied to the heater core pipes, and the repair will not be effective. Cut off the excess length of the tie strap. Refer to the arrow in the illustration above for the proper tie strap installation location.
5. Install the vacuum hose to the power brake booster.
6. Install the coolant reservoir back into it's mounting bracket.
7. Remove the fender covers and close the hood.

Parts are currently available from GMSPO.

For vehicles repaired under warranty, use: