Firenza L4-121 2.0L (1983)
Labor Operation Number:
T4655
Labor Time:
.2 hrs.
Trouble Code:
92
Technical Service Bulletin # 88T1536F
Date: 900201
Exhaust System - Moan or Boom At 1900 RPM and 2400 RPM
SUBJECT
EXHAUST MOAN - INSTALL DAMPENER ON EXHAUST
PIPE REAR OF CATALYTIC CONVERTER
MODELS/YEARS
1982-88 FIRENZA MODELS EQUIPPED WITH 4-
CYLINDER ENGINES
NUMBER:
88-T-153
CORP.REF.NO: 076601R
DATE:
February 1990
SECTION:
6F
Some customers may comment about an exhaust moan or boom that occurs primarily at 1900 rpm and at 2400 rpm.
This condition can be corrected by installing a mass dampener, (P/N 10137382) using a 2-inch exhaust clamp (P/N 25517282) per the following
instructions and illustration.
1.
Remove the nuts and saddle from the clamp assembly. Discard one of the nuts.
2.
Locate clamp assembly on exhaust pipe rearward of the exhaust pipe to catalytic converter flange. The clamp assembly may be located directly
behind the catalytic converter flange, as long as there is sufficient clearance to heat shields.
Do not install the dampener/clamp assembly rearward of the downward bend in the exhaust pipe; there will not be enough ground clearance at
this location.
3.
Position the saddle on the clamp and install the dampener hand-tight onto one side of the clamp (whichever side has the most clearance from the
underbody heat shields).
4.
Install one nut on the other side of the clamp and torque it to 20 N-m (15 lbs.ft.). Check the torque of the dampener to make sure that it is at least
20 N-m (15 lbs.ft.). Do not over-torque the dampener or the clamp nut, or the exhaust pipe may be crushed.
5.
Do NOT install a nut on the dampener side of the clamp assembly.
Parts are currently available from GMSPO.
