A/C - Whistle Noise When Coming Off Full Hot Setting
File In Section: 1 - HVACBulletin No.: 43-11-07
Date: November, 1994
Subject:
Whistle Noise from HVAC when Coming Off Full Hot Position (Install Seal)
Models:
1991-94 Buick LeSabre, Park Avenue
1991-92 Cadillac Fleetwood
1991-94 Cadillac DeVille
1992-94 Cadillac Eldorado, Seville
1994 Cadillac Concours
1991-94 Oldsmobile Eighty Eight, Ninety Eight
1991-94 Pontiac Bonneville
Condition
Some owners may comment on a whistle noise when the temperature mix door starts to move away from the full hot position.
Cause
The temperature door seal does not come off its seat evenly, causing a small "leak". The whistle is originating through this leak.
Correction
A foam seal, P/N 52470996, needs to be installed behind the temperature door to prevent whistle. To repair this condition, perform the following procedure:
1. Refer to appropriate Service Manual to remove heater core.
2. Once heater core is removed, identify the temperature door seal and the area where the new seal is to be installed (refer to Figure 1).
3. Place duct tape on top of temperature door, pull upper lip of seal down and toward passenger side of vehicle, then stick tape to door to position seal to gain access to area where new seal will be installed (refer to Figure 2).
4. Thoroughly clean area where seal is to be installed. There should be no oil, dust or debris in this area.
Important:
When installing seal, be sure to align the tapered edge toward the hinge side of the temperature door.
5. To install seal, place double sided tape (available locally) on finger, then place properly oriented seal on finger (sticky side out). Once seal Is on finger, place seal through opening above the temperature door.
6. Remove duct tape from temperature door.
Important:
After installation, verify that the seal is properly positioned so that the tapered edge Is touching the tapered portion of the heater case. A mirror may be used to verify installation.
Also verify that the seal does NOT scrape on the temperature door.
7. Follow Service Manual procedures to install heater core and programmer.
Parts information
Parts are currently available from GMSPO.
Warranty information
For vehicles repaired under warranty, use: