Work Flow

CUSTOMER INTERVIEW

Interview the customer if possible, to determine the conditions that exist when the noise occurs. Use the Diagnostic Worksheet during the interview to document the facts and conditions when the noise occurs and any of the customer's comments; refer to MIR-39, "Diagnostic Worksheet". This information is necessary to duplicate the conditions that exist when the noise occurs.

• The customer may not be able to provide a detailed description or the location of the noise. Attempt to obtain all the facts and conditions that exist when the noise occurs (or does not occur).

• If there is more than one noise in the vehicle, be sure to diagnose and repair the noise that the customer is concerned about. This can be accomplished by a test drive with the customer.

• After identifying the type of noise, isolate the noise in terms of its characteristics. The noise characteristics are provided so the customer, service adviser and technician are all speaking the same language when defining the noise.

• Squeak – (Like tennis shoes on a clean floor) Squeak characteristics include the light contact/fast movement/brought on by road conditions/hard surfaces = higher pitch noise/softer surfaces = lower pitch noises/edge to surface = chirping
• Creak – (Like walking on an old wooden floor) Creak characteristics include firm contact/slow movement/twisting with a rotational movement/pitch dependent on materials/often brought on by activity.

• Rattle – (Like shaking a baby rattle) Rattle characteristics include the fast repeated contact/vibration or similar movement/loose parts/missing clip or fastener/incorrect clearance.

• Knock – (Like a knock on a door) Knock characteristics include hollow sounding/sometimes repeating/often brought on by driver action.

• Tick – (Like a clock second hand) Tick characteristics include gentle contacting of light materials/loose components/can be caused by driver action or road conditions.

• Thump – (Heavy, muffled knock noise) Thump characteristics include softer knock/dead sound often brought on by activity.

• Buzz – (Like a bumble bee) Buzz characteristics include high frequency rattle/firm contact.

• Often the degree of acceptable noise level will vary depending upon the person. A noise that a technician may judge as acceptable may be very irritating to the customer.

• Weather conditions, especially humidity and temperature, may have a great effect on noise level.

DUPLICATE THE NOISE AND TEST DRIVE

If possible, drive the vehicle with the customer until the noise is duplicated. Note any additional information on the Diagnostic Worksheet regarding the conditions or location of the noise. This information can be used to duplicate the same conditions when the repair is reconfirmed.

If the noise can be duplicated easily during the test drive, to help identify the source of the noise, try to duplicate the noise with the vehicle stopped by doing one or all of the following: 1) Close a door.

2) Tap or push/pull around the area where the noise appears to be coming from.

3) Rev the engine.

4) Use a floor jack to recreate vehicle “twist”.

5) At idle, apply engine load (electrical load, half-clutch on M/T model, drive position on A/T model).

6) Raise the vehicle on a hoist and hit a tire with a rubber hammer.

• Drive the vehicle and attempt to duplicate the conditions the customer states exist when the noise occurs.

• If it is difficult to duplicate the noise, drive the vehicle slowly on an undulating or rough road to stress the vehicle body.

LOCATE THE NOISE AND IDENTIFY THE ROOT CAUSE

1. Narrow down the noise to a general area. To help pinpoint the source of the noise, use a listening tool (Engine Ear or mechanics stethoscope).

2. Narrow down the noise to a more specific area and identify the cause of the noise by:
• Removing the components in the area that is are suspected to be the cause of the noise. Do not use too much force when removing clips and fasteners, otherwise clips and fastener can be broken or lost during the repair, resulting in the creation of new noise.

• Tapping or pushing/pulling the component that is are suspected to be the cause of the noise.

Do not tap or push/pull the component with excessive force, otherwise the noise will be eliminated only temporarily.

• Feeling for a vibration by hand by touching the component(s) that is are suspected to be the cause of the noise.

• Placing a piece of paper between components that is are suspected to be the cause of the noise.

• Looking for loose components and contact marks.

Refer to MIR-37, "Inspection Procedure".

REPAIR THE CAUSE

• If the cause is a loose component, tighten the component securely.

• If the cause is insufficient clearance between components: - Separate components by repositioning or loosening and retightening the component, if possible.

- Insulate components with a suitable insulator such as urethane pads, foam blocks, felt cloth tape or urethane tape. These insulators are available through the authorized Nissan Parts Department.

CAUTION:
Never use excessive force as many components are constructed of plastic and may be damaged.

NOTE:

• URETHANE PADS
Insulates connectors, harness, etc.

• INSULATOR (Foam blocks) Insulates components from contact. Can be used to fill space behind a panel.

• INSULATOR (Light foam block) • FELT CLOTHTAPE
Used to insulate where movement does not occur. Ideal for instrument panel applications.

The following materials, not available through NISSAN Parts Department, can also be used to repair squeaks and rattles.

• UHMW(TEFLON) TAPE
Insulates where slight movement is present. Ideal for instrument panel applications.

• SILICONE GREASE
Used in place of UHMW tape that is be visible or does not fit.

Note: Will only last a few months.

• SILICONE SPRAY
Used when grease cannot be applied.

• DUCT TAPE
Used to eliminate movement.

CONFIRM THE REPAIR
Confirm that the cause of a noise is repaired by test driving the vehicle. Operate the vehicle under the same conditions as when the noise originally occurred. Refer to the notes on the Diagnostic Worksheet.

Inspection Procedure

Refer to Table of Contents for specific component removal and installation information.

INSTRUMENT PANEL

Most incidents are caused by contact and movement between: 1. Cluster lid A and instrument panel 2. Acrylic lens and combination meter housing 3. Instrument panel to front pillar garnish 4. Instrument panel to windshield 5. Instrument panel mounting pins 6. Wiring harnesses behind the combination meter 7. A/C defroster duct and duct joint

These incidents can usually be located by tapping or moving the components to duplicate the noise or by pressing on the components while driving to stop the noise. Most of these incidents can be repaired by applying felt cloth tape or silicon spray (in hard to reach areas). Urethane pads can be used to insulate wiring harness.

CAUTION:
Never use silicone spray to isolate a squeak or rattle. If the area is saturated with silicone, the recheck of repair becomes impossible.

CENTER CONSOLE

Components to pay attention to include: 1. Shifter assembly cover to finisher 2. A/C control unit and cluster lid C 3. Wiring harnesses behind audio and A/C control unit

The instrument panel repair and isolation procedures also apply to the center console.

DOORS

Pay attention to the following: 1. Finisher and inner panel making a slapping noise 2. Inside handle escutcheon to door finisher 3. Wiring harnesses tapping 4. Door striker out of alignment causing a popping noise on starts and stops

Tapping or moving the components or pressing on them while driving to duplicate the conditions can isolate many of these incidents. The areas can usually be insulated with felt cloth tape or insulator foam blocks to repair the noise.

TRUNK

Trunk noises are often caused by a loose jack or loose items put into the trunk by the customer.

In addition look for the following: 1. Trunk lid dumpers out of adjustment 2. Trunk lid striker out of adjustment 3. Trunk lid torsion bars knocking together 4. A loose license plate or bracket

Most of these incidents can be repaired by adjusting, securing or insulating the item(s) or component(s) causing the noise.

SUNROOF/HEADLINING

Noises in the sunroof/headlining area can often be traced to one of the following:
1. Sunroof lid, rail, linkage or seals making a rattle or light knocking noise 2. Sunvisor shaft shaking in the holder 3. Front or rear windshield touching headlining and squeaking

Again, pressing on the components to stop the noise while duplicating the conditions can isolate most of these incidents. Repairs usually consist of insulating with felt cloth tape.

SEATS

When isolating seat noise it is important to note the position the seat is in and the load placed on the seat when the noise occurs. These conditions should be duplicated when verifying and isolating the cause of the noise.

Cause of seat noise include: 1. Headrest rods and holder 2. A squeak between the seat pad cushion and frame 3. Rear seatback lock and bracket

These noises can be isolated by moving or pressing on the suspected components while duplicating the conditions under which the noise occurs. Most of these incidents can be repaired by repositioning the component or applying urethane tape to the contact area.

UNDERHOOD

Some interior noise may be caused by components under the hood or on the engine wall. The noise is then transmitted into the passenger compartment.

Causes of transmitted underhood noise include: 1. Any component mounted to the engine wall 2. Components that pass through the engine wall 3. Engine wall mounts and connectors 4. Loose radiator mounting pins 5. Hood bumpers out of adjustment 6. Hood striker out of adjustment

These noises can be difficult to isolate since they cannot be reached from the interior of the vehicle. The best method is to secure, move or insulate one component at a time and test drive the vehicle. Also, engine RPM or load can be changed to isolate the noise. Repairs can usually be made by moving, adjusting, securing, or insulating the component causing the noise.

Diagnostic Worksheet