Issue #1 - Belt Slippage
Experience a squealing noise that occurs during the operation of your engine and may continue after the warm-up period. This squealing would come from the belt area and could also be catagorized as a "whine". It is recommended that you resolve this issue by replacing the belts, as they may have been weakened if they have been slipping for very long. The cause is either a bad belt or belts, or a tensioner is bad / improperly installed. It could also only make the annoying squeal until it warms up. This can be caused by a leaking water pump or thermostat housing onto the belts. After the car warms up and the belts have created enough friction to dry up the leaking coolant the noise goes away. (Make sure the there is absolutely no leakage onto the belts by checking for coolant stains at or around the belt route under the car)
Issue #2 - Bad Tensioner Pulley (the one that I experienced)
I was experiencing a squealing noise that occurs during the first 5-10 minutes after startup. I was suffering from this squealing at the belt area and I was sure that it was not (issue #1). A few months earlier I had replaced my plastic impeller water pump and bakelite thermostat housing and while I was at it I thought I would rid myself of this issue by replacing the belts. However, the problem noise was still there. It only makes the annoying squeal when I first start it and drive for about 5 minutes then it goes away completely. There is absolutely no leakage onto the belts either (issue #1). I am starting to suspect the idler pulley...the problem is which one? The other suspect was the alternator (issue #3) ...I checked it out extensively and used all of the shade-tree mechanic tricks I could remember. Using an old radiator hose, and putting it to my ear, trying to isolate the noise, anyway...I found where I thought it was coming from. The culprit was the upper belt tensioner pulley next to the alternator. It was squealing like a bitch and I used a small tube (3/8" vacuum line) to direct some WD-40 to the backside of the pulley bearing. The squealing went away instantly when the WD touched the bearing race. I realize now that it was probably when I repalced the belts to do the water pump that I tapped the tensioner pulleys to remove several ounces of dust/dirt that was in the bearings. I think once the dust was removed they loosened up and started to make noise. I eventually replaced the tensioner pulley with a new one about a week later when the WD-40 must have dried up (very easy job). Hope this helps who ever else has this issue.
Issue #3 - Bad Alternator Bearings
Experiencing a squealing noise that occurs during the first 5-10 minutes after startup or continuously while engine is running. The squealing sounds like it is at the belt area and be sure that it was not (issue #1 or issue #2). Be sure that there is absolutely no leakage onto the belts either (issue #1). The suspect is now the alternator. This is more costly. I recommend checking it out extensively and used all of the shade-tree mechanic tricks you can. Old radiator hose to the ear to try to isolate the noise.
Text Source:
http://www.geocities.com/thesynic/E36squeal.html
Experience a squealing noise that occurs during the operation of your engine and may continue after the warm-up period. This squealing would come from the belt area and could also be catagorized as a "whine". It is recommended that you resolve this issue by replacing the belts, as they may have been weakened if they have been slipping for very long. The cause is either a bad belt or belts, or a tensioner is bad / improperly installed. It could also only make the annoying squeal until it warms up. This can be caused by a leaking water pump or thermostat housing onto the belts. After the car warms up and the belts have created enough friction to dry up the leaking coolant the noise goes away. (Make sure the there is absolutely no leakage onto the belts by checking for coolant stains at or around the belt route under the car)
Issue #2 - Bad Tensioner Pulley (the one that I experienced)
I was experiencing a squealing noise that occurs during the first 5-10 minutes after startup. I was suffering from this squealing at the belt area and I was sure that it was not (issue #1). A few months earlier I had replaced my plastic impeller water pump and bakelite thermostat housing and while I was at it I thought I would rid myself of this issue by replacing the belts. However, the problem noise was still there. It only makes the annoying squeal when I first start it and drive for about 5 minutes then it goes away completely. There is absolutely no leakage onto the belts either (issue #1). I am starting to suspect the idler pulley...the problem is which one? The other suspect was the alternator (issue #3) ...I checked it out extensively and used all of the shade-tree mechanic tricks I could remember. Using an old radiator hose, and putting it to my ear, trying to isolate the noise, anyway...I found where I thought it was coming from. The culprit was the upper belt tensioner pulley next to the alternator. It was squealing like a bitch and I used a small tube (3/8" vacuum line) to direct some WD-40 to the backside of the pulley bearing. The squealing went away instantly when the WD touched the bearing race. I realize now that it was probably when I repalced the belts to do the water pump that I tapped the tensioner pulleys to remove several ounces of dust/dirt that was in the bearings. I think once the dust was removed they loosened up and started to make noise. I eventually replaced the tensioner pulley with a new one about a week later when the WD-40 must have dried up (very easy job). Hope this helps who ever else has this issue.
Issue #3 - Bad Alternator Bearings
Experiencing a squealing noise that occurs during the first 5-10 minutes after startup or continuously while engine is running. The squealing sounds like it is at the belt area and be sure that it was not (issue #1 or issue #2). Be sure that there is absolutely no leakage onto the belts either (issue #1). The suspect is now the alternator. This is more costly. I recommend checking it out extensively and used all of the shade-tree mechanic tricks you can. Old radiator hose to the ear to try to isolate the noise.
Text Source:
http://www.geocities.com/thesynic/E36squeal.html
