Northstar Engines and System Technical Discussion Discussion, 98 SLS screeching noise from egen. in Cadillac Engine Discussion; Hi all new hear
Theres been a screeching noise coming from the front
of the egen.
It was just a ...
There are TWO belts and tensioners in a 98 SLS: the water pump belt is in the "rear" (driver's side) of the engine, behind the water pump cover which is bolted to the coolant crossover. The pump is driven off the front intake cam by a small belt and tensioner. The main accessory drive is in the front (passenger side).
If your noise is in the front (passenger side) of the engine, and replacing the main serpentine belt tensioner did not help, then there are 3 more possibilities: the idler pulley bearing, the alternator bearings, or the a/c compressor clutch bearings are going bad.
If the noise is, in fact, coming from the water pump area, then there's a whole different procedure to remove and change that setup.
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Sorry its a 96 not 98 Wifes car
squealing New belt tensioner,and idler arm pully And alternator.
So the water pump is on the driver side
The pump is driven off the front intake cam by a small belt and tensioner
The main accessory drive is in the front (passenger side).
Could this be the noise it sounds like its cooming from the top front side
96 SLS 104000 mi
Thanks Mike H Livoina MI
Automobile(s): White Diamond '03 DHS (with DTS floor shift)
Re: 98 SLS screeching noise from egen.
"Top front side" of the motor is the passengers side. I would suspect the idler or tensioner pulley bearing. Release the tension on the tensioner with a 1/2" breaker bar. Put the drive lug in the square hole on the back side and use it as a lever. Then spin each pulley by hand and see if there is any looseness, roughness or noise. If they are OK, check the A/C compressor clutch down below.
I know this is going to sound stupid, because it sounds like a belt or bearing from what you describe, but check the backfire valve on the end of the intake manifold by the P/S pump. It can make a high pitched whistling that gets very annoying. Move it a bit with a screwdriver or other object to try to get it to seal. My '97 STS did this and I thought for a minute it was the alternator. Another thing that can make a whistling/high pitched sound is the EGR tubes (flex pipes) running to the throttle body and coolant crossover. If they aren't sealed properly they can emit a very annoying sound too.
When you have it figured out let us know- we're curious!