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98' STS
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39 Posts
Discussion Starter #1
So I purchased a 1998 STS this fall. New engine, new wheels, suspension and breaks. However, towards the ends of winter I noticed a whine when I started the engine. The whine is most prevalent at around 1,200-1,900 rpm. At around 2,000 rpm it seems to quiet down or disappear. The transmission is working properly, I was thinking it could be the power steering pump. When I go to put the car in drive it seems very hard to turn in either direction (eventually when it is a bit warmer it is easy to turn). I was also thinking it could be the idler pully. Any thoughts would be greatly appreciated, other than the annoying sound the car runs and drives wonderfully.:D
 

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98' STS
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39 Posts
Discussion Starter #3
I checked the P/S fluid, it was a bit low. So filled to the app line. Sound still persists, but it was running low, could not find any visible leaks.
 

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Super Moderator
2010 DTS
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87,433 Posts
It could be any of those and more. The only way to find out is an inspection, preferably with a stethoscope.
 

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98' STS
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39 Posts
Discussion Starter #5
Turns out the idler pulley was replaced last summer. Will try the stethoscope, but it is just odd it disappears or diminishes at that particular rpm window.
 

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98' STS
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Discussion Starter #6
So I used the stethoscope I have in the garage, could not find anything conclusive. Any more suggestions?
 

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2002 Seville SLS, all black--261,000 miles
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934 Posts
So I used the stethoscope I have in the garage, could not find anything conclusive. Any more suggestions?
Uh, shooting in the dark, turn off radio and HVAC. Take off the splash shield underneath and get somebody in the car to rev through the 1200-1900 rpm range while you listen to locate the sound with your ears. Try it on your knees, left, right, front. Jiggle some stuff. Scope on the water pump. Foot on the brake, shift from forward gears to reverse to forward to reverse...always listening...Check trans fluid and oil levels...Make sure serpentine belt is perfectly on track.

If I were you what would bug me the most is that there's this loud repeatable sound that doesn't come from anywhere in particular. Any vibrations anywhere?
 

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98' STS
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39 Posts
Discussion Starter #8
Thanks. I will give that a try tomorrow! Im guessing based on what I've read it is the water pump pulley as they tend to have bearings go around 50k. Either that or power steering. Other than that no vibrations whatsoever, the car is solid and pulls as hard as ever, no acceleration problems. I just finished replacing the front and rear suspension, so it is essentially a brand new car. Any hints with the water pump? aka, any easy way to get at it?
 

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2010 DTS
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Im guessing based on what I've read it is the water pump pulley as they tend to have bearings go around 50k.
Not true. My '97 had the original WP at 107K when I sold it. They are quite reliable. The shaft seal will usually go before the bearings. The tensioner pulley is another story, but it's on the other end of the engine from the accessories.
 

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2002 Seville SLS, all black--261,000 miles
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934 Posts
Thanks. I will give that a try tomorrow! Im guessing based on what I've read it is the water pump pulley as they tend to have bearings go around 50k. Either that or power steering. Other than that no vibrations whatsoever, the car is solid and pulls as hard as ever, no acceleration problems. I just finished replacing the front and rear suspension, so it is essentially a brand new car. Any hints with the water pump? aka, any easy way to get at it?
Check out the Tech Tips section. I hear there's a special tool attachment that really eases the job. I've never done a water pump on this car, so I can't say much.
 
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