Feel, Hear, See, Smell: Hear Part One

   This week we'll look at some of the things you can hear are wrong with your car. As you drive you can hear many sounds in your car and when something is not right, you will usually hear it. It just doesn't sound right or different from how it normally sounds.

   As with any car problem, the causes can range from a mere inconvenience to major repair. Here are some things to look for when you have a car that doesn't handle or respond properly.

   You should note that these are the most likely causes of a particular problem, but not necessarily the cause of the problem you are experiencing. Some of the possible causes listed may not even apply to your vehicle.

Thumping and Clunking

• Clunking noise during braking:
  When you step on the brakes there is a clunking noise. Depending on how fast you are going and how hard you ally the brakes changes the intensity of the noise. The sound may or may not travel up through the steering column.

  Possible causes:
  

  1. There are worn steering system components: Inspect steering system and replace worn parts as required.

  2. The suspension system is loose or worn: Inspect suspension system and replace worn parts as required.

  3. The disc brake caliper is not mounted properly: Repair or replace mounting hardware as required.

  4. Some of the brake hardware is damaged or missing: or replace disk pad mounting hardware.

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• Clunking from under the car when gears change:
  With either a manual or automatic transmission, when you shift gears there is a momentary hesitation and then a clunking noise. The noise could come from the front or back of the vehicle. This noise started gradually and became worse over time.

  Possible causes:
  

  1. Worn CV-joints: Replace CV-joints.

  2. Worn U-joints: Replace U-joints.

  3. The differential unit may have too much backlash: Check and adjust differential backlash or replace differential. (Generally not a DIY job)

  4. The engine's idle speed may be set too high: Check and adjust ignition timing.

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• Clunking from under the car while accelerating:
  When you accelerate there is a momentary hesitation and then a clunking noise. The noise could come from the front or back of the vehicle. Sometimes the noise occurs if you step on the gas or let up while the car is moving. Many times you can feel the noise in the body of the car. This noise started gradually and became worse over time.

  Possible causes:
  

  1. Shock absorbers are bad: Replace shocks or shock mounts.

  2. Shock mounts are broken: Replace shock mounts.

  3. Loose or broken exhaust parts: Repair or replace exhaust parts as required.

  4. Loose, worn, or broken motor and/or transmission mounts: Replace broken mounts.

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• Clunking from the engine that worsens when engine speed increases:
  When you press on the gas pedal, the engine makes a clunking noise. The noise increases as you press harder on the gas pedal. The noise is there whether you are in gear or in neutral. Sometimes the noise is not noticeable when you are letting the engine idle but occurs as soon as you press on the gas pedal. Normally, the problem begins gradually, but the noise may go unnoticed. As the problem worsens, the noise gets louder.

  Possible causes:
  

  1. Worn engine bearings: Replace engine bearings or engine.

  2. Broken engine parts: Inspect accessory (P/S pump. A/C compressor, etc.) for loose or broken parts, replace as required.

  3. Loose or missing flywheel-mounting bolts: Tighten or replace mounting bolts.

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  Grinding, Squealing, Scraping and Growling

• Growling noise from air conditioner:
  The engine runs well and makes no unusual noises until you turn on the air conditioning. Then you hear a growling or knocking noise only when the air conditioning is on. The noise will get louder and more noticeable over time.

  Possible causes:
  

  1. The bearings in the air conditioning compressor are bad: Replace air conditioning compressor.

  2. The clutch on the air conditioning compressor is weak or worn: Replace air conditioning compressor clutch.

  3. The air conditioning compressor is bad: Replace air conditioning compressor.

  4. A control valve in the air conditioning system is bad: Replace air conditioning control valves.

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