Fault-tracing information

Condition 

Fig 1: Identifying Transmission

Courtesy of VOLVO CARS OF NORTH AMERICA.

The problem occurs when the car is driven beside a wall, in a garage or through a tunnel. It applies to earlier 850 and S/V70 models. For naturally aspirated engines up to and including model year 99, turbocharged engines and diesel engines up to and including model year 98. On later car models remedy the problem using a twin-mass flywheel.

The sound can easily be confused with tire or wind noise. Remember that 205 tires make more noise than 195 tires and that the road surface is important when correctly judging transmission rattle. Test drive the car on a dry, flat road with as little traffic on it as possible. The rattle does not normally occur in a transmission where the temperature is below +30 °C.

Possible Source 

• Incorrect level or type of transmission fluid
• Poor sound insulation around the steering column lead-in on the firewall.

Fault symptom[s] 

• Rattling in the transmission when driving alongside a wall, in a garage or through a tunnel
• Rattling in the transmission when accelerating in first, second or third gears
• The customer complains about wind noise from the tires.

Condition 

Fig 1: Identifying Flywheel

Courtesy of VOLVO CARS OF NORTH AMERICA.

The problem is concept-related and often connected to the engine control system. All cars have this problem. It is most obvious on diesel cars. The noise disappears when the clutch is depressed and the engine started and stopped. It is especially obvious when the transmission is hot.

Possible Source 

• Defective clutch
• Defective twin mass flywheel.

Fault symptom[s] 

• The clutch or twin mass flywheel rattle when starting off or stopping
• The transmission rattles when one starts or stops the engine.