Muffler - Vibration Noise While Driving

86subaru2

NUMBER 09-22-86

APPLICABILITY ALL 1985 AND 1986 VEHICLES DATE 05-21-86


SUBJECT: MUFFLER NOISE


Should you encounter a muffler that gives off a vibration noise while driving, a simple procedure of drilling a hole in the outer skin can be performed to alleviate the condition.

By drilling a hole in the outer skin of the muffler allows ambient air to travel freely between the muffler skin and the inner plate. The air cools the inner plate to prevent it from warping from heat expansion and resonating on the outer skin.

FIGURE 1:

First verify the noise. Then raise the vehicle and locate the lot number on the support plate at the front of the muffler. If the lot number is not within the range shown in Figure 1, replace the muffler following the repair steps found in the 1986 Service Manual, section 2- 9, page 7. If the lot number is within the range shown in Figure 1, perform the operational steps that follow:

MATERIALS REQUIRED

High Temperature Paint (Spray or Brush-on) All Purpose Grease

TOOLS REQUIRED

Drill 5/64" Drill Bit Drill Stop Hammer Center Punch Tape Measure

FIGURE 2:

STEP 1) Locate a point as shown in Figure 2.

FIGURE 3:

STEP 2) Prepare a 5/64" drill bit with a drill stop located less than 1/8" from the tip of the drill bit. This will stop the drill bit from drilling into the inner plate of the double wall muffler (See Figure 3).
STEP 3) Drill a hole at the point that was located in step one, remembering to drill through the outer wall only. Apply a small amount of grease on the end of the drill bit to prevent the drill filings from falling into the hole being drilled.

STEP 4) Coat the drilled area around the hole with high temperature paint to prevent rusting.

STEP 5) Road test the vehicle to confirm that the muffler noise has stopped.

This procedure can be claimed for vehicles within the terms of the Subaru warranty using one of the following:

Failure Code EAE-25 Operation # A229-281 Muffler Replacement 0.3 hrs
Failure Code EAE-48 Operation # A129-001 Muffler Repair 0.3 hrs