So, your dryer suddenly started making a noise you don’t recognize. You tried listening harder to what it has to say but realized, that dryers can’t talk. Or can they? The specific noise your dryer is making may be the key to figuring out what the problem is, how serious it is, and whether you should start shopping for a new one. 

Dryer Is Making a Grinding Noise.  
Nothing is more alarming than the sound of metal grinding against metal—especially when there is an appliance running. If your dryer is making a grinding noise, the culprit is usually the drum bearing. The drum bearing is in the back of the appliance behind the dryer drum. When this part gets worn down, the drum rubs against the back of the casing and causes a distinct grinding noise. Sometimes this grinding is also accompanied by a high-pitch squealing or squeaking noise. The drive belt will need to be removed to diagnose such a problem. So, for that reason, it’s best to call a dryer repair professional as soon as you hear a grinding sound.  

Dryer Is Making a Screeching Noise. 
Another common, but unsettling dryer noise is a loud screeching sound when you turn it on. The screeching noise when you turn the dryer on is usually caused by a broken idler pulley, sometimes called a tensioner. To identify if this is the problem, follow these steps. 
Unplug your dryer, and carefully move it to an area where you have enough room to inspect the back of the appliance. You may need to disconnect the air vent duct.  
If your dryer is gas-powered or hardwired to your home’s electrical system, stop here. The safest next step is consulting a professional who is highly qualified to inspect the dryer without causing an additional problem to the existing connections. 
If you are able to move the unit away from the wall, inspect the idler pulley. It looks like a wheel on a moveable bracket just above the dryer belt that loops around the drum. (The drive pulley is just beneath the belt; don’t confuse this part with the idler pulley.) If you can turn the idler pulley manually, it’s in working order. If it doesn’t turn or is difficult to turn, have it replaced by an expert.  

Dryer Is Making a Thumping Noise.  
A dryer that is making a thumping noise is perplexing indeed. If it is making a thumping noise while running, you’ll need to determine if there are any balled-up towels or heavy objects in the dryer drum that may be causing of the sound. If you’ve inspected your laundry and can’t find any reason for the noise, it’s most likely coming from one of the dryer’s inner components.  
A flattened roller. If you don’t use your dryer frequently or it’s been sitting unused for a while, it may have a flattened roller. The thumping noise could be from the flat spot on the roller making the rotation as the drum spins. Try running an empty cycle to allow the roller to re-shape. If this doesn’t resolve the problem, you’ll need to have the roller repaired. 
A worn-out roller. When your dryer is making a loud noise, whether it’s thumping or creaking, a worn-down roller is often the cause. When this part no longer makes a solid connection with the drum, you’ll hear a sound as the drum rotates. The part will need to be replaced entirely. 
A damaged belt. If your roller is in good condition, the thumping may be coming from a damaged or frayed dyer belt. However, most repair companies will replace your roller, belt, and idler pulley at the same time to ensure all three are working correctly together and wearing out evenly. 

SOURCE: mrappliance.com

So, your dryer suddenly started making a noise you don’t recognize. You tried listening harder to what it has to say but realized, that dryers can’t talk. Or can they? The specific noise your dryer is making may be the key to figuring out what the problem is, how serious it is, and whether you should start shopping for a new one. 

Dryer Is Making a Grinding Noise.  
Nothing is more alarming than the sound of metal grinding against metal—especially when there is an appliance running. If your dryer is making a grinding noise, the culprit is usually the drum bearing. The drum bearing is in the back of the appliance behind the dryer drum. When this part gets worn down, the drum rubs against the back of the casing and causes a distinct grinding noise. Sometimes this grinding is also accompanied by a high-pitch squealing or squeaking noise. The drive belt will need to be removed to diagnose such a problem. So, for that reason, it’s best to call a dryer repair professional as soon as you hear a grinding sound.  

Dryer Is Making a Screeching Noise. 
Another common, but unsettling dryer noise is a loud screeching sound when you turn it on. The screeching noise when you turn the dryer on is usually caused by a broken idler pulley, sometimes called a tensioner. To identify if this is the problem, follow these steps. 
Unplug your dryer, and carefully move it to an area where you have enough room to inspect the back of the appliance. You may need to disconnect the air vent duct.  
If your dryer is gas-powered or hardwired to your home’s electrical system, stop here. The safest next step is consulting a professional who is highly qualified to inspect the dryer without causing an additional problem to the existing connections. 
If you are able to move the unit away from the wall, inspect the idler pulley. It looks like a wheel on a moveable bracket just above the dryer belt that loops around the drum. (The drive pulley is just beneath the belt; don’t confuse this part with the idler pulley.) If you can turn the idler pulley manually, it’s in working order. If it doesn’t turn or is difficult to turn, have it replaced by an expert.  

Dryer Is Making a Thumping Noise.  
A dryer that is making a thumping noise is perplexing indeed. If it is making a thumping noise while running, you’ll need to determine if there are any balled-up towels or heavy objects in the dryer drum that may be causing of the sound. If you’ve inspected your laundry and can’t find any reason for the noise, it’s most likely coming from one of the dryer’s inner components.  
A flattened roller. If you don’t use your dryer frequently or it’s been sitting unused for a while, it may have a flattened roller. The thumping noise could be from the flat spot on the roller making the rotation as the drum spins. Try running an empty cycle to allow the roller to re-shape. If this doesn’t resolve the problem, you’ll need to have the roller repaired. 
A worn-out roller. When your dryer is making a loud noise, whether it’s thumping or creaking, a worn-down roller is often the cause. When this part no longer makes a solid connection with the drum, you’ll hear a sound as the drum rotates. The part will need to be replaced entirely. 
A damaged belt. If your roller is in good condition, the thumping may be coming from a damaged or frayed dyer belt. However, most repair companies will replace your roller, belt, and idler pulley at the same time to ensure all three are working correctly together and wearing out evenly. 

SOURCE: mrappliance.com