DEMonte1997
Aficionado
Name : Rick
Age : 45
Location : CT
Joined : 2009-03-03
Post Count : 1429
Merit : 37
 | | Subject: Medium to high pitched harmonic sound at around 1500rpms.... Tue Feb 02, 2010 10:36 pm | |
| I'm guessing one of my pulleys is about to take a dump... The sound is intermittent. First heard it a few days ago. It went away and then came back tonight. Only hear it around 1500-1800rpms. Any revs under or past that and it goes away. Sound in the cabin almost seems like the HVAC fan but turning the CC off totally doesn't change anything. I'm leaning towards an idler or tensioner but haven't ruled out the alt. Anyone else come across a similar issue? I've never had a pulley frag on me before... :/ | |
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Rickw
Guru
Name : Rick
Location : Lancaster, MA
Joined : 2008-09-13
Post Count : 6282
Merit : 119
| | Subject: Re: Medium to high pitched harmonic sound at around 1500rpms.... Tue Feb 02, 2010 11:39 pm | |
| Would be best to try and duplicate it while in park and have someone else bring the RPM up while you listen to the various pulleys or, pumps, AC compressor and SC. Basically everything that rotates.
Don't rule out the A/C compressor as it runs also in the winter time. Turn on the Defroster to listen to just that.
Edit: Never mind about the AC compressor, I just re-read your post and you said you've listened with the climate control turned off.
Deek's suggestion below is even better if you can't determine which one it is.
How many miles on this engine.?
What's the history of pulley and belt changes.?
It may be due to have all the pulleys changed if it hasn't been done and your near 100K miles. Usually when one goes the rest are soon to follow.
Last edited by Rickw on Wed Feb 03, 2010 9:00 am; edited 1 time in total | |
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deekster_caddy
Master
Name : Derek
Age : 52
Location : Reading, MA
Joined : 2007-01-31
Post Count : 7717
Merit : 109
| | Subject: Re: Medium to high pitched harmonic sound at around 1500rpms.... Wed Feb 03, 2010 8:37 am | |
| Take the belts off their tensioners and spin everything by hand. | |
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AA
Administrator
Name : Aaron
Age : 46
Location : C-bus, Ohio
Joined : 2007-01-13
Post Count : 18448
Merit : 252
| | Subject: Re: Medium to high pitched harmonic sound at around 1500rpms.... Wed Feb 03, 2010 8:58 am | |
| It does seem to be the symptom of a failing idler or tensioner pulley. Do you have more than 85k miles on the car?
If it is a pulley, you may have less than 200 miles to get this fixed before all heck breaks loose. Have this diagnosed asap! _________________ '05 GTO 6.0L • 6-spd • 95k miles • 0-60: 4.8s • 16.9 avg MPG • Nelson Ledges Lap: 1:26'95 Celica GT 2.2L • 5-spd • 165k miles • 0-60: yes'98 SC Riviera • 281k miles • 298 HP/370 TQ • 0-60: 5.79s • ET: 13.97 @ 99.28 • 4087 lb • 20.1 avg MPG • Nelson Ledges Lap: 1:30
3.4" pulley • AL104 plugs • 180º t-stat • FWI w/K&N • 1.9:1 rockers • OR pushrods • LS6 valve springs • SLP headers • ZZP fuel rails
KYB GR2 struts • MaxAir shocks • Addco sway bars • UMI bushings • GM STB • Enkei 18" EV5s w/ Dunlop DZ101s • F-body calipers
EBC bluestuff/Hawk HP plus • SS lines • Brembo slotted discs • DHP tuned • Aeroforce • Hidden Hitch^^^ SOLD ^^^  '70 Ninety-Eight Holiday Coupe 455cid • 116k miles^^^ SOLD ^^^ | |
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DEMonte1997
Aficionado
Name : Rick
Age : 45
Location : CT
Joined : 2009-03-03
Post Count : 1429
Merit : 37
| | Subject: Re: Medium to high pitched harmonic sound at around 1500rpms.... Wed Feb 03, 2010 11:31 am | |
| Car has 145,000. I don't think the pulleys have ever been done previous but it has newer belts. I'm going to replace all the pulleys in the next day-hopefully before one frags and takes a belt out with it.
Thanks for the suggestions guys!!! | |
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DEMonte1997
Aficionado
Name : Rick
Age : 45
Location : CT
Joined : 2009-03-03
Post Count : 1429
Merit : 37
| | Subject: Re: Medium to high pitched harmonic sound at around 1500rpms.... Wed Feb 03, 2010 3:41 pm | |
| I changed out the accessory tensioner, supercharger tensioner and ribbed supercharger idler pulleys today and the sound is gone. I hope that takes care of it until it gets warmer out. I'll do the crappy idler then. lol Thanks to Derek for selling me a couple of his metal pulleys a few months ago. Saved me a LOT of $$!!  | |
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