Lumina APV V6-191 3.1L (1990)
Technical Service Bulletin # 91279A1A
Date: 920701
A/C - Noise At Highway Speeds/Certain Heater Positions
Number: 91-279-1A
Section: 1A
Date: JULY 1992
Corporate Bulletin No.: 131103R
ASE No.: A7
Subject:
WHISTLE NOISE AT HIGHWAY SPEEDS AND/OR CERTAIN HEATER CONTROL POSITIONS
Model and Year:
1990-91 LUMINA APV
THIS BULLETIN CANCELS AND SUPERSEDES DEALER SERVICE BULLETIN NO., 91-279-1A, DATED APRIL 1991. A NEW ANTENNA
MAST HAS BEEN RELEASED FOR "DIAGNOSIS" STEP 1, ALONG WITH THE PART AVAILABLILITY AND WARRANTY INFORMATION
FOR THE ANTENNA. A SOURCE DISCLAIMER LISTED IN # 1 WAS ALSO ADDED. ALL COPIES OF 91-279-1A SHOULD BE DISCARDED.
Some customers of 1990-91 U-Vans may comment about whistling sounds either while driving the vehicle at highway speeds and/or with the heater
controls in certain positions.
Conditions:
1.
Constant whistle noise while driving at highway speeds or while driving with heater controls in any position EXCEPT MAX.
2.
Whistle noises with the heater controls in the DEFROST OR MIX modes
OR:
with the control in the HEAT, MIX or DEFROST modes with the TEMP LEVER from 0 to 1/4 position and in 3/4 position (opposite the MIX
button).
Causes:
1.
Speed related noises are most likely due to high velocity air passing through the cowl panel grill, that may be mispositioned.
2.
Noises with the heater controls in certain positions may be due to EITHER air leakage past the hinge area of the defroster door
OR:
air passing through the narrow opening between the temperature door baffle and the outside edge of the slave door.
Diagnosis:
May be performed by road testing the vehicle and having a 10 mm wrench in your possession OR by testing the Heater and A/C system with the controls
set in positions as noted in the condition sections above.
1.
Road test the vehicle at speeds between 30 and 55 MPH. Note any noises present and pull off the road into a safe parking area. Using the 10 mm
wrench, remove the antenna mast, retest the vehicle as before and note any change in noise.
-
If the noise changed and no whiste noise is heard, the condition is antenna related.
-
Replace the antenna mast with P/N 10220990. If the noise DID NOT CHANGE, perform Correction # 1 only
Part Availability:
Parts are expected to be available on July 13, 1992. In case of limited inventory, parts will be placed on 400 control to waive VIP surcharges. Only
verifiable emergency VIP orders will be accepted. SPO will make every effort to obtain parts. However, the part will be shipped premium transportation
at dealer's expense and all other order types will be placed on backorder until the 400 control is removed.
Labor Operation Number:
R0220
Use applicable labor time guide for labor hours.
2.
Whistle noises with controls in certain positions may be diagnosed by parking the vehicle in a QUIET area and noting noises while the controls are
positioned as indicated in the condition sections above.
