C7 Engine Noise
10-03-2014, 01:56 PM
#1
Navigator
Thread Starter
Member Since: Jul 2013
Posts: 9
Likes: 0
Received 0 Likes
on
0 Posts
C7 Engine Noise
My 2014 C7 has developed a engine noise that sounds like a bad bearing in a alternator or water pump. My Vette convertible has the Z51 and Performance Exhaust pkg's. Current milage is 1,900. The noise can be heard with engine hot or just after starting. Turning off A/C and Performance Exhaust makes no difference. Noise does not change with RPM so it would appear to not be the new variable valve system. There are no dashboard warnings nor error checks per my Chevy dealer who is scratching his head over what it could be. No GM service advisories, etc.
can be found. The noise is somewhat new as it was not there when I took Museum delivery and miles added since. It appears to not be the dry sump which bulletins say can be noisy.
Anyone experience this and what the cause was ??? Thanx.
can be found. The noise is somewhat new as it was not there when I took Museum delivery and miles added since. It appears to not be the dry sump which bulletins say can be noisy.
Anyone experience this and what the cause was ??? Thanx.
10-03-2014, 06:04 PM
#2
Race Director
Everything I can think of would change with rpm or amount of air flowing in the intake system. Even exhaust flow changes with power added or subtracted. You say it is like a howl, how loud? Does it start immediately when the engine starts or take a minute or so to develop. Only thing I can think of is something electrical that as current is applied resonates a frequency that sounds like a howl. That would not change with engine power/rpm change. Take a large screwdriver and use it as a stethoscope by holding the screw tip on engine components and placing your ear near/on the handle. Yea, sounds odd, it really works! Maybe you can narrow the sound down to an engine component.
Last edited by Larry/car; 10-03-2014 at 06:14 PM.
10-04-2014, 05:57 PM
#3
Navigator
Thread Starter
Member Since: Jul 2013
Posts: 9
Likes: 0
Received 0 Likes
on
0 Posts
Everything I can think of would change with rpm or amount of air flowing in the intake system. Even exhaust flow changes with power added or subtracted. You say it is like a howl, how loud? Does it start immediately when the engine starts or take a minute or so to develop. Only thing I can think of is something electrical that as current is applied resonates a frequency that sounds like a howl. That would not change with engine power/rpm change. Take a large screwdriver and use it as a stethoscope by holding the screw tip on engine components and placing your ear near/on the handle. Yea, sounds odd, it really works! Maybe you can narrow the sound down to an engine component.
10-04-2014, 09:19 PM
#4
Race Director
The noise is heard at idle. Either right after a cold start or after any trip distance with engine hot. It is a rhythmic mechanical noise that sounds like a bad alternator or water pump from my decades of automotive experience. I did use a auto stethoscope topside around engine cavity and found no localization for noise source. You can hear it up to 100 feet away. It appears that the front wheel wells act like a megaphone to project out. I have attached a mp3 file of the noise recording. You will hear it distinctly on top of the base engine idle sound.
10-11-2014, 03:35 PM
#6
Cruising
Member Since: Aug 2014
Location: San Bernardino California
Posts: 13
Likes: 0
Received 0 Likes
on
0 Posts
The mp3 file will not play on my macbook using itunes, quicktime or VLC.
I have a C5 with 50k miles which makes a sound like a bad alternator bearing or PS pump bearing. When I cold start the car, the sound is not there and then abruptly appears after about 45 seconds or so. I' going to start my own thread in the C5 forum but since I recorded the sound, I thought that it might help if it sounds like yours does.
Good luck!
I have a C5 with 50k miles which makes a sound like a bad alternator bearing or PS pump bearing. When I cold start the car, the sound is not there and then abruptly appears after about 45 seconds or so. I' going to start my own thread in the C5 forum but since I recorded the sound, I thought that it might help if it sounds like yours does.
Good luck!
10-11-2014, 06:15 PM
#7
Team Owner
Member Since: Aug 2007
Location: I live my life by 2 rules. 1) Never share everything you know. 2)
Posts: 136,148
Received 2,400 Likes
on
1,365 Posts
St. Jude Donor '11-'12-'13, '16-'17-'18
Your attachment is NOT an MP3. In fact, Goldwave can't figure out exactly WHAT it is 
10-12-2014, 12:03 AM
#8
Burning Brakes
10-12-2014, 02:49 AM
#10
10-12-2014, 10:16 AM
#11
Instructor
I had a loud, grinding sound coming from the aft part of the engine, and I could only hear it at idle. It ended up being a bad torque tube. After the torque tube was replaced I no longer heard the sound.
10-12-2014, 10:17 PM
#12
Heel & Toe
Member Since: Jun 2012
Location: TN
Posts: 23
Likes: 0
Received 0 Likes
on
0 Posts
Mine was one that had a rod bearing issue. I heard a small very faint chirping sounds (like an alternator bearing sound) before it complete went out. Started for a couple of days and then it died. It was very faint and I was surprised when it did go out. The noise was inconsistent of RPMs, gears, etc..I have a 2014 convertible Z51 auto.
I listened to your audio but did not hear anything that sounded like it. But I was thinking alternator bearing when I heard mine. Hope it is nothing for you.
I listened to your audio but did not hear anything that sounded like it. But I was thinking alternator bearing when I heard mine. Hope it is nothing for you.