Howling Noise
If any noise is present check the transmission
fluid level. This is done by accessing the transmission from underneath the
car. The transmission is equipped with a fluid level inspection port on the side
of the transmission case. This port is accessed by removing a plug that is held
in with threads much like a nut and bolt assembly works. The fluid level should
be at the bottom of the port, if the fluid level is low re-fill as needed and recheck.
(Never rotate the transmission when checking fluid level).
Transmission Fluid Level Inspection Port Servicing an Automatic Transmission - Automatic transmissions make specific noises when a malfunction occurs. An automatic transmission is a hydraulic pressure driven system and it can make different noises than a manual transmission. If the transmission filter becomes plugged due to debris, it can make a howling noise. If the fluid level is low, you might hear a gurgling sound, caused by the pump scavenging fluid inside the transmission pan. Most internal failures are due to bearing, clutch or hard part failure. When such a failure occurs the transmission can make grinding, howling sounds or no noise at all. When a transmission has a major failure you might hear a loud pop which could mean a drive component inside the transmission has failed and the car will stop moving.
Transmission Planetary Gear Set
Anytime you here an automatic transmission noise inspect the fluid level by starting the car on level ground and allow the engine it idle. Next remove the fluid level dipstick and using a shop or paper towel to whip the stick clean. Reinsert the stick completely and remove it it inspect the fluid level. Add fluid as needed, also inspect the fluid condition, it should be a clear pink or red color with a normal hydraulic oil odor. If the fluid condition is dark and has a pungent smell it probably means the transmission is having a problem and needs to be rebuilt or replaced. If the transmission filter is plugged it can also cause a howling noise as the pump is fighting to pull fluid through it. To check for this condition remove the transmission oil pan and inspect the filter condition and replace if needed. Some transmissions have no fluid level dip stick, these vehicles require replacement whenever a transmission malfunction occurs.
Locate and Remove the Transmission Fluid Level Indicator Checking Engine Accessory Bearings - Engine accessories such as alternator, water pump, power steering pump and air conditioner compressor utilize bearings. These bearings can create a howling noise has malfunctioning while the engine is operating. To check for this condition shut the engine off, then remove the serpentine belt. With the belt removed spin the accessories and check for noise or rough spots while a particular accessory is rotating. If a noise or rough spot is present replace that accessory with a new or rebuild unit.
Typical Engine Accessory Configuration Checking a Fan Clutch - The engine cooling fan system in your car is designed to move air through the radiator when the vehicle is at slower speeds or stopped. This air flow removes heat from the coolant created by the engine using the radiator as a conductor. A clutch fan has the ability to disengage when not in use allowing the engine to work more efficiently while allowing a better user experience. When a clutch fan fails it causes the coolant to retain heat, forcing the engine to run hot and eventually overheat. A clutch fan is engaged and disengaged from operation by a temperature produced from the radiator. This fan clutch is constructed using a silicon grease and temperature sensitive coil spring that expands and contracts with heat. As the spring absorbs heat it expands engaging the clutch fan utilizing engine power to drive the fan. As the engine coolant cools the fan clutch will disengage. A clutch fan can fail one of two ways, it can either lock the fan to the clutch causing poor mileage and a howling sound, like an airplane is taking off next to you. Or the silicon grease can start to leak causing the fan clutch not to lock up allowing the fan to "freewheel", failing to pull air through the radiator when needed. To check a fan clutch condition the engine must be off. Inspect the fan clutch for leakage at the front or rear of the unit (input shaft and temperature controlled expansion spring). If leakage is observed the fan clutch has failed and needs replacing. Next, take the fan blade and turn it, the fan blade should free wheel, if you cannot turn the fan blade the clutch has locked up and needs to be replaced. Also, there should be no or very little play as you turn the fan, if excess play exists replace the fan clutch.
Engine Fan Clutch (fan blade not attached) If further assistance is needed, our certified car repair technicians are ready to answer your car questions. Related Car Repair Information
Transmission Fluid Level Inspection Port Servicing an Automatic Transmission - Automatic transmissions make specific noises when a malfunction occurs. An automatic transmission is a hydraulic pressure driven system and it can make different noises than a manual transmission. If the transmission filter becomes plugged due to debris, it can make a howling noise. If the fluid level is low, you might hear a gurgling sound, caused by the pump scavenging fluid inside the transmission pan. Most internal failures are due to bearing, clutch or hard part failure. When such a failure occurs the transmission can make grinding, howling sounds or no noise at all. When a transmission has a major failure you might hear a loud pop which could mean a drive component inside the transmission has failed and the car will stop moving.
Transmission Planetary Gear Set
Anytime you here an automatic transmission noise inspect the fluid level by starting the car on level ground and allow the engine it idle. Next remove the fluid level dipstick and using a shop or paper towel to whip the stick clean. Reinsert the stick completely and remove it it inspect the fluid level. Add fluid as needed, also inspect the fluid condition, it should be a clear pink or red color with a normal hydraulic oil odor. If the fluid condition is dark and has a pungent smell it probably means the transmission is having a problem and needs to be rebuilt or replaced. If the transmission filter is plugged it can also cause a howling noise as the pump is fighting to pull fluid through it. To check for this condition remove the transmission oil pan and inspect the filter condition and replace if needed. Some transmissions have no fluid level dip stick, these vehicles require replacement whenever a transmission malfunction occurs.
Locate and Remove the Transmission Fluid Level Indicator Checking Engine Accessory Bearings - Engine accessories such as alternator, water pump, power steering pump and air conditioner compressor utilize bearings. These bearings can create a howling noise has malfunctioning while the engine is operating. To check for this condition shut the engine off, then remove the serpentine belt. With the belt removed spin the accessories and check for noise or rough spots while a particular accessory is rotating. If a noise or rough spot is present replace that accessory with a new or rebuild unit.
Typical Engine Accessory Configuration Checking a Fan Clutch - The engine cooling fan system in your car is designed to move air through the radiator when the vehicle is at slower speeds or stopped. This air flow removes heat from the coolant created by the engine using the radiator as a conductor. A clutch fan has the ability to disengage when not in use allowing the engine to work more efficiently while allowing a better user experience. When a clutch fan fails it causes the coolant to retain heat, forcing the engine to run hot and eventually overheat. A clutch fan is engaged and disengaged from operation by a temperature produced from the radiator. This fan clutch is constructed using a silicon grease and temperature sensitive coil spring that expands and contracts with heat. As the spring absorbs heat it expands engaging the clutch fan utilizing engine power to drive the fan. As the engine coolant cools the fan clutch will disengage. A clutch fan can fail one of two ways, it can either lock the fan to the clutch causing poor mileage and a howling sound, like an airplane is taking off next to you. Or the silicon grease can start to leak causing the fan clutch not to lock up allowing the fan to "freewheel", failing to pull air through the radiator when needed. To check a fan clutch condition the engine must be off. Inspect the fan clutch for leakage at the front or rear of the unit (input shaft and temperature controlled expansion spring). If leakage is observed the fan clutch has failed and needs replacing. Next, take the fan blade and turn it, the fan blade should free wheel, if you cannot turn the fan blade the clutch has locked up and needs to be replaced. Also, there should be no or very little play as you turn the fan, if excess play exists replace the fan clutch.
Engine Fan Clutch (fan blade not attached) If further assistance is needed, our certified car repair technicians are ready to answer your car questions. Related Car Repair Information