Exhaust System - Rattle/Exhaust Leak From Rear Of Vehicle
Bulletin No: 01-002/13Last Issued: 01/14/2013
Subject:
2009-2012 MAZDA6 - RATTLE NOISE AND/OR EXHAUST LEAK NOISE FROM REAR OF VEHICLE
BULLETIN NOTE
*^ This bulletin supercedes the previous bulletin 01-025/12, issued on 11/16/12. The DESCRIPTION has been revised.
^ Changes are noted by asterisks.*
APPLICABLE MODELS/VINS
2009-2012 Mazda6 vehicles produced before June 7, 2012
DESCRIPTION
*Some vehicles may exhibit exhaust leaking noise from the rear of the vehicle. The noise may be caused by a gap between the exhaust hanger bracket and flange, which allows moisture *containing road salt* to enter and cause the exhaust studs to rust and possibly break off.
The welding location of the exhaust hanger bracket and flange has been changed to ensure the hanger bracket and flange are flush, with no gaps *that could allow intrusion of moisture containing road salt.*
*The purpose of the bulletin is to cute and clean the welding location of the exhaust hanger bracket and re-attach it, so the hanger bracket and flange are flush with no gaps. to prevent intrusion of moisture containing road salt.*
Customers having this concern should have their vehicle repaired using the following repair procedure.
REPAIR PROCEDURE
Replace any broken or missing exhaust studs between the main silencer and pre-silencer.
1. Verify customer concern.
2. Safely raise vehicle on hoist.
3. Locate the exhaust joint between the main silencer and pre-silencer as shown.
4. Inspect for broken or missing exhaust studs:
- If either stud is broken or missing, proceed to the next step.
- If neither stud is broken or missing, refer to the instructions on MS3 online or the Workshop Manual for further troubleshooting information.
5. Remove the main silencer:
a. Spray rubber hanger that supports main silencer to ease the removal from the body hanger.
b. Remove stud nuts and discard them.
c. 3.7L Only: Remove nuts from the crossover pipe, then discard the nuts and gaskets.
d. While supporting the main silencer, remove the rubber hanger from the body hanger, then place the main silencer on a work bench.
e. Remove gaskets and discard them.
6. Press out both broken and unbroken studs from main silencer flange that mates with the pre-silencer flange:
a. 3.7L engine right main silencer shown below (2.5L engine is similar).
b. Using a wire brush, remove any loose rust on the flange the studs were removed from.
7. Locate the hanger bracket that supports the rear of the pre-silencer.
a. Remove the rubber hanger from the rear hanger and support the pre-silencer with the tall jack stand.
b. With an angle grinder, remove the welds (A) that attach the hanger bracket to the flange (in order to separate the bracket from the flange).
c. Remove any weld or weld splatter from the nut tightening surface of the hanger bracket (B). Also, remove the remaining weld from the flange that was attached to the bracket and make it a smooth surface.
d. Remove any loose rust from flange surface behind the hanger bracket and the hanger bracket itself.
8. Prep rubber hangers and install separated pre-silencer hanger bracket:
a. Spray liquid lubricant on rubber hanger for the main silencer where it connects to the body and the rubber hanger that is used for the rear pre-silencer hanger bracket.
b. Install the separated hanger bracket to the rear pre-silencer rubber hanger.
9. Reinstall the main silencer:
a. Lift the main silencer up and attach the rubber hanger to the body hanger.
b. 3.7L Only: Attach the crossover pipe to the left main silencer after installing the new gasket and hand start the new nuts.
c. Align the main silencer flange, pre-silencer flanges, separated pre-silencer bracket (front of pre-silencer flange) and new gasket.
d. Insert new bolts from the main silencer side and hand start the nuts to the bolts from the pre-silencer separated hanger bracket side as shown below.
e. Align the flange edges so there is no overlap on any side.
f. Torque the joint by putting the torque wrench on the bolt head and hand wrench on the nut.
Tightening Torque: 36.9 ft. lbs. {50 N-m, 5.1 kgf-m)
g. 3.7L Only: Torque the joint between the crossover pipe to the left main silencer.
Tightening Torque: 33.2 ft. lbs. {45 N-m, 4.6 kgf-m)
10. Verify repair:
a. 3.7L Only: Check that all the joints have been secured.
b. Check that the rubber exhaust hangers are in correct position.
c. Start the engine and confirm the noise has been eliminated.
PART(S) INFORMATION
WARRANTY INFORMATION
Disclaimer