Strange whirring/grinding nosie from accessories or fans?
01-19-2004, 05:34 AM
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Car: 88 Camaro IROC T-Top - Gunmetal Grey
Engine: 305 TPI V8
Transmission: Auto
Strange whirring/grinding nosie from accessories or fans?
I start up my car on the drive and leave it a minute or two.
The rad fans are OFF.
Then there is a strange, and rather difficult to explain, whirring/grating noise from the front left hand (as looking at the car) area. The air con and heater etc are swtiched off.
It's not the engine itself for sure, must be an accessory or fan?
Any ideas what it could be?
It don't sound right.
When the fans come on they both come on together (even though the gauge on the dash is nowhere near operating temp yet) and I thought they were supposed to come on seperately anyway?
The rad fans are OFF.
Then there is a strange, and rather difficult to explain, whirring/grating noise from the front left hand (as looking at the car) area. The air con and heater etc are swtiched off.
It's not the engine itself for sure, must be an accessory or fan?
Any ideas what it could be?
It don't sound right.
When the fans come on they both come on together (even though the gauge on the dash is nowhere near operating temp yet) and I thought they were supposed to come on seperately anyway?
01-19-2004, 09:18 AM
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Car: 88' IROCZ
Engine: 388 TPI Motown 350 Race block
Transmission: 700R4
Axle/Gears: 2.77
Noise
Noise could be from idler pulley bearings , or something similar, or it could be the belt itself. Try a belt spray. If it's the A/C pulley, somethings turning the A/C on will either increase, or decrease the noise. You try to pin-point the noise using an engine stethoscope, or a long rod just don't get it caught in the belt, or pulleys.
The fans should turn on independantly. Mine are tied together to the computer.
Only one fan is hard-wired to a coolant temperature switch set to turn on above 200 °F, the other is controlled by the computer that gets its temperature reading from a sensor located on the front to of the intake, depending on engine load and temperature this fan can turn at different times, and can also be turn on by an A/C high pressure switch.
The fans should turn on independantly. Mine are tied together to the computer.
Only one fan is hard-wired to a coolant temperature switch set to turn on above 200 °F, the other is controlled by the computer that gets its temperature reading from a sensor located on the front to of the intake, depending on engine load and temperature this fan can turn at different times, and can also be turn on by an A/C high pressure switch.
01-19-2004, 09:22 PM
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Car: Guess
Engine: Crazy 8
Transmission: So close to being a manual I can taste it
Probably a bearing...Idler on tensioner if so equipped, alternator, PS, water pump too.
Take a stethoscope and listen to the accessories as they turn. Or a long screwdriver works sometimes to. Listen for whatever makes the loudest noise...
Take a stethoscope and listen to the accessories as they turn. Or a long screwdriver works sometimes to. Listen for whatever makes the loudest noise...
Last edited by 92 zzz28; 01-20-2004 at 01:00 PM.
01-20-2004, 11:12 AM
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Car: 88 Camaro IROC T-Top - Gunmetal Grey
Engine: 305 TPI V8
Transmission: Auto
I'll give it a try this weekend.
Cheers guys!
I was just puzzled as it was really loud and just suddenly started up after a few mins.
Cheers guys!
I was just puzzled as it was really loud and just suddenly started up after a few mins.
01-22-2004, 04:09 PM
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Car: 1989 TTA
Engine: LC2
Transmission: Worn-out 200R4
Axle/Gears: BW 9-bolt, 3.27's
My water pump was going south, it made more of a grinding noise, not much of a whine, though. Sounded terrible, till I replaced it. Now I can her my diff clutches doing wierd things when they're warm and I turn the wheel, plus, the water pump racket masked the fact that my u-joint's loose, too. 
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