Grinding Noise
Thread Starter
Pro
Joined: Sep 2006
Posts: 731
Likes: 9
From: Ivins, Utah
Grinding Noise
My car makes a grinding or groaning noise when I start it, but it doesn't happen all the time, when it does happen it's after it's been sitting for a while.
It grinds for about 5 - 10 seconds and then it's done, no more till next time and it doesn't seem to happen every time I start it.
The noise is comming from the front, like in the engine compartment and it sounds like it's on the right side.
I've looked for anything wrong and I can't see anything.
Any ideas ??
Thanks
It grinds for about 5 - 10 seconds and then it's done, no more till next time and it doesn't seem to happen every time I start it.
The noise is comming from the front, like in the engine compartment and it sounds like it's on the right side.
I've looked for anything wrong and I can't see anything.
Any ideas ??
Thanks
Thread Starter
Pro
Joined: Sep 2006
Posts: 731
Likes: 9
From: Ivins, Utah
Air pump warming up the cats ??
I know what both of these items are I just never knew this happened at all.
Any idea what the air pump is for, I mean, what else does it do ??
The sound does seem to be coming from that general area, although the air pump is more on the left side.
My grinding/ grumbling noise does not seem to be related to the A/C ... I thought for a while it was the ABS brake system, but it doesn't really seem to be. A bad pulley would make the noise all the time.
(My Toyota has a bad alternator bearing and it howls all the time)
(My Toyota is a good car, almost as reliable as my Chevys)
Obviously this doesn't seem to be a common problem.
Thanks
I know what both of these items are I just never knew this happened at all.
Any idea what the air pump is for, I mean, what else does it do ??
The sound does seem to be coming from that general area, although the air pump is more on the left side.
My grinding/ grumbling noise does not seem to be related to the A/C ... I thought for a while it was the ABS brake system, but it doesn't really seem to be. A bad pulley would make the noise all the time.
(My Toyota has a bad alternator bearing and it howls all the time)
(My Toyota is a good car, almost as reliable as my Chevys)
Obviously this doesn't seem to be a common problem.
Thanks
Safety Car
Joined: Dec 2004
Posts: 3,526
Likes: 18
From: Santa Fe TX
I have the same noise (I think) and its absolutely unbearable. It makes me think a rod is going to go through the block, but oil pressure is normal. Its like a metal on metal squeal/grind/high pitched rumble.
Trouble is, in order to troubleshoot (belts pulleys etc), I have to turn off the car, and the noise never returns, even if I do nothing but wait 5 seconds.
My car has done it 2 times in the last month, and always after sitting for more than 2 days, but not everytime it sits 2 days.
Trouble is, in order to troubleshoot (belts pulleys etc), I have to turn off the car, and the noise never returns, even if I do nothing but wait 5 seconds.
My car has done it 2 times in the last month, and always after sitting for more than 2 days, but not everytime it sits 2 days.
Thread Starter
Pro
Joined: Sep 2006
Posts: 731
Likes: 9
From: Ivins, Utah
But it happens after I release the key and when the engine is running.
Stops after a few seconds of running, maybe after it's been running 5 - 10 seconds, sometimes maybe 15 seconds.
Thanks
Burning Brakes
Joined: Dec 2003
Posts: 1,066
Likes: 9
From: Eddy Texas
May well be the A.I.R. pump. It runs for a few seconds on startup. Can you verify also that it is not the starter hanging. I haven't heard of any C5s with that problem, but it happens.
Here'a link that explains the A.I.R. system.
http://forums.corvetteforum.com/show....php?t=1932324
Here'a link that explains the A.I.R. system.
http://forums.corvetteforum.com/show....php?t=1932324
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Racer
Joined: Sep 2007
Posts: 320
Likes: 28
May well be the A.I.R. pump. It runs for a few seconds on startup. Can you verify also that it is not the starter hanging. I haven't heard of any C5s with that problem, but it happens.
Here'a link that explains the A.I.R. system.
http://forums.corvetteforum.com/show....php?t=1932324
Here'a link that explains the A.I.R. system.
http://forums.corvetteforum.com/show....php?t=1932324
my best bet would be the starter gear hangin up
Safety Car
Joined: Dec 2004
Posts: 3,526
Likes: 18
From: Santa Fe TX
Starter hanging could be OP's problem - but mine doesn't happen right after crank. Only after idle for 1-2 minutes. Oil pressure is fine when it happens. I'm leaning towards Air pump or Clutch throwout bearing or belt. Unfortunately the two times it has happened over the last month, it was so nerve racking that I quickly shut off the engine...Didn't return on restart.
Tech Contributor
Joined: Dec 2003
Posts: 19,384
Likes: 87
From: Horncastle Lincolnshire, England
2023 C5 of the Year Finalist - Unmodified
Do you have Twilight Sentinel selected on. Does the grinding start when the headlamps raise in the garage? If so its the headlight gears.
Thread Starter
Pro
Joined: Sep 2006
Posts: 731
Likes: 9
From: Ivins, Utah
I still haven't checked my codes, I should do that.
It's not the starter hanging up, I know that god awful noise and this is not that.
It's not the headlight gears either, Twilight Sentinel is not on, headlight do not move when I start the car.
I honestly thought it was the A/C clutch, but the A/C works fine all the time.
Thanks
It's not the starter hanging up, I know that god awful noise and this is not that.
It's not the headlight gears either, Twilight Sentinel is not on, headlight do not move when I start the car.
I honestly thought it was the A/C clutch, but the A/C works fine all the time.
Thanks
2nd Gear
Joined: Mar 2008
Posts: 2
Likes: 0
I have the same problem on my 2004. It started when the car was 1.5 years old (about 2.5 years ago) and has done it off and on since. Nobody seems to know what it is or they can't duplicate it. It seems to be on the left side of the engine and lasts consistently about 30 seconds. It also seems to happen more frequently in warmer weather.
Thread Starter
Pro
Joined: Sep 2006
Posts: 731
Likes: 9
From: Ivins, Utah
I have the same problem on my 2004. It started when the car was 1.5 years old (about 2.5 years ago) and has done it off and on since. Nobody seems to know what it is or they can't duplicate it. It seems to be on the left side of the engine and lasts consistently about 30 seconds. It also seems to happen more frequently in warmer weather.
Check your harmonic balancer to see if it is wobbling, it could be grinding into the front cover
Check your harmonic balancer to see if it is wobbling, it could be grinding into the front cover
I've watched the balancer while it's running and I don't see a wobble, should I shut the engine off and try moving it by hand ??
Thanks
2nd Gear
Joined: Mar 2008
Posts: 2
Likes: 0
Since I am new to this forum, I'm not sure if I should bring this up but I contacted GM directly at cac@chevrolet.com about this subject last Wednesday and I at least got a reply the next day. They ended up putting me in touch with Quality Chevrolet in Escondido, CA, the dealer that couldn't fix it while the car was under warranty. I'm not sure if anything will come of it. Maybe if enough Corvette owners contact them, something will be done?
Thread Starter
Pro
Joined: Sep 2006
Posts: 731
Likes: 9
From: Ivins, Utah
I think I've found my noise, it seems to be coming from the A/C unit, only at start up.
When it's making the noise I can turn the A/C off and the noise goes away not to return till I've started it about 5 - 10 more times, it doesn't happen very often, maybe just the A/C clutch ... gives me something to look at anyways.
When it's making the noise I can turn the A/C off and the noise goes away not to return till I've started it about 5 - 10 more times, it doesn't happen very often, maybe just the A/C clutch ... gives me something to look at anyways.
