Strange sound while warming up.
Thread Starter
Race Director
Joined: Dec 2004
Posts: 13,760
Likes: 75
From: Haymarket VA
Strange sound while warming up.
I have a Z51 A6 3LT car. When I start it up and for the next few minutes I get a humming/droning sound. It's almost like diode noise but lower in frequency. It sound like its coming from the right side of the car in front of the passenger seat. I don't know if you can hear it outside the car but you definitely can inside. It seems to go away once the car is warmed up for a couple of minutes.
Anyone else have this?
Anyone else have this?
Team Owner
Joined: Sep 2005
Posts: 29,113
Likes: 2,194
From: Big Bend Country, TX
St. Jude Donor '06-'07-'08-'09-'10-'11-'12-'13-'14-'15- '16-'17-‘18-‘19-'20-'21
NCM Lifetime Member
Have you checked ...........
The feeding tray for the mice must be empty. The humming/droning sound you hear is the surviving mice praying over their deceased . . . . . . 
Pro
Joined: Dec 1999
Posts: 545
Likes: 286
From: Lords Valley PA
Yep - I have same sound - - I believe it is the electric 'air pump' to supply extra air for the cats to heat up quicker. Once the cats have 'lit', the air pump shuts down - no more 'whine', and everybody is 'happy'. This is what I 'believe'... but I'm sure others will have additional wisedom on this subject.
Thread Starter
Race Director
Joined: Dec 2004
Posts: 13,760
Likes: 75
From: Haymarket VA
Yep - I have same sound - - I believe it is the electric 'air pump' to supply extra air for the cats to heat up quicker. Once the cats have 'lit', the air pump shuts down - no more 'whine', and everybody is 'happy'. This is what I 'believe'... but I'm sure others will have additional wisedom on this subject.
Thread Starter
Race Director
Joined: Dec 2004
Posts: 13,760
Likes: 75
From: Haymarket VA
I turned everything off but the engine and it still made the noise. I think it is the air pump. Just to confirm, does anyone know where the air pump lives in a C7?
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Thread Starter
Race Director
Joined: Dec 2004
Posts: 13,760
Likes: 75
From: Haymarket VA
Ken,
I'm sure you can make me smarter but this is from the C5 service manual.
According to FSM noise problem could be:
1. loose drive pulley
2. loose mounting bolts/screws
3. worn or dirty bearings
4. faulty diode or faulty stator
I had a similar noise in my C5 and it turned out to be a faulty diode in the voltage regulator/alternator. That's why I described the sound as such.
Kevin
I'm sure you can make me smarter but this is from the C5 service manual.
According to FSM noise problem could be:
1. loose drive pulley
2. loose mounting bolts/screws
3. worn or dirty bearings
4. faulty diode or faulty stator
I had a similar noise in my C5 and it turned out to be a faulty diode in the voltage regulator/alternator. That's why I described the sound as such.
Kevin
Team Owner
Joined: Aug 2007
Posts: 136,140
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From: I live my life by 2 rules. 1) Never share everything you know. 2)
St. Jude Donor '11-'12-'13, '16-'17-'18
Ken,
I'm sure you can make me smarter but this is from the C5 service manual.
According to FSM noise problem could be:
1. loose drive pulley
2. loose mounting bolts/screws
3. worn or dirty bearings
4. faulty diode or faulty stator
I had a similar noise in my C5 and it turned out to be a faulty diode in the voltage regulator/alternator. That's why I described the sound as such.
Kevin
I'm sure you can make me smarter but this is from the C5 service manual.
According to FSM noise problem could be:
1. loose drive pulley
2. loose mounting bolts/screws
3. worn or dirty bearings
4. faulty diode or faulty stator
I had a similar noise in my C5 and it turned out to be a faulty diode in the voltage regulator/alternator. That's why I described the sound as such.
Kevin
Team Owner
Joined: Sep 2005
Posts: 29,113
Likes: 2,194
From: Big Bend Country, TX
St. Jude Donor '06-'07-'08-'09-'10-'11-'12-'13-'14-'15- '16-'17-‘18-‘19-'20-'21
NCM Lifetime Member
Melting Slicks
Joined: Jun 2004
Posts: 2,130
Likes: 54
From: Granbury, Pecan Plantation TX
I have a Z51 A6 3LT car. When I start it up and for the next few minutes I get a humming/droning sound. It's almost like diode noise but lower in frequency. It sound like its coming from the right side of the car in front of the passenger seat. I don't know if you can hear it outside the car but you definitely can inside. It seems to go away once the car is warmed up for a couple of minutes.
Anyone else have this?
Anyone else have this?
Melting Slicks
Joined: Jun 2004
Posts: 2,130
Likes: 54
From: Granbury, Pecan Plantation TX
Also saw a Techlink bulletin that in another model (Not Corvette) there was an exact description of the sound that was related to the Brake Booster pump which last around 20 seconds. So it could be a little longer in the Vette.