knocking sound
Thread Starter
Heel & Toe
Joined: Nov 2011
Posts: 20
Likes: 0
From: Houston Texas
Pro
Joined: Aug 2003
Posts: 620
Likes: 45
From: Raleigh NC
Was told "It's normal".
Service rep said he went out to a 427 and it did the same thing.
Hmmm, not sure if I buy that.
I'm going to ask about it at one of the technical sessions at the Bash later this month.
Get a second opinion.
Service rep said he went out to a 427 and it did the same thing.
Hmmm, not sure if I buy that.
I'm going to ask about it at one of the technical sessions at the Bash later this month.
Get a second opinion.
Thread Starter
Heel & Toe
Joined: Nov 2011
Posts: 20
Likes: 0
From: Houston Texas
Yeah, can't be normal, my 07 Z51 didn't do it!
Le Mans Master
Joined: Dec 2004
Posts: 5,492
Likes: 808
From: West coast CA
It sounds just like an HVAC failure I've encountered on several other cars.
The usual setup consists of an air door that's actuated by a bell crank at the end of a little plastic gearbox driven by a stepper motor.
One of the plastic gears inside the box strips and makes that sound. The HVAC control unit cycles the motor repeatedly trying to get the door to swing.
The usual setup consists of an air door that's actuated by a bell crank at the end of a little plastic gearbox driven by a stepper motor.
One of the plastic gears inside the box strips and makes that sound. The HVAC control unit cycles the motor repeatedly trying to get the door to swing.
Pro
Joined: Aug 2003
Posts: 620
Likes: 45
From: Raleigh NC
It sounds just like an HVAC failure I've encountered on several other cars.
The usual setup consists of an air door that's actuated by a bell crank at the end of a little plastic gearbox driven by a stepper motor.
One of the plastic gears inside the box strips and makes that sound. The HVAC control unit cycles the motor repeatedly trying to get the door to swing.
The usual setup consists of an air door that's actuated by a bell crank at the end of a little plastic gearbox driven by a stepper motor.
One of the plastic gears inside the box strips and makes that sound. The HVAC control unit cycles the motor repeatedly trying to get the door to swing.
I'm annoyed they brushed it off so quickly as normal.
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Brett Foote
Race Director
Joined: Apr 2000
Posts: 15,344
Likes: 4,009
From: Texas
: on the service adviser. If it was normal he should have taken you out to the 427 so you could hear it. FWIW, my 2013 GS does not have the noise.
Team Owner
Joined: Jun 2005
Posts: 46,295
Likes: 2,596
From: Northern, VA
St. Jude Donor '15
"In honor of jpee"
It sounds just like an HVAC failure I've encountered on several other cars.
The usual setup consists of an air door that's actuated by a bell crank at the end of a little plastic gearbox driven by a stepper motor.
One of the plastic gears inside the box strips and makes that sound. The HVAC control unit cycles the motor repeatedly trying to get the door to swing.
The usual setup consists of an air door that's actuated by a bell crank at the end of a little plastic gearbox driven by a stepper motor.
One of the plastic gears inside the box strips and makes that sound. The HVAC control unit cycles the motor repeatedly trying to get the door to swing.
If I'm wrong I'd be glad to hear it. But after driving around for about a year with that clacking sound, mine got worse and I just paid for it to be done about three months ago.
Good luck.
Pro
Joined: Aug 2003
Posts: 620
Likes: 45
From: Raleigh NC
Sorry to resurrect this old post.
After I was told the clicking noise was normal, I learned to live with it, because it didn't bother me that much.
That was back in April.
Since then I did find out that when it was in bi-level mode, even with the fan on its highest setting, little or no air would come out of the dash vents. It was coming out of the defrost vents.
A-ha!
Something concrete I could show them.
So this morning I take it in for it's 10,000 service.
I show them this.
They call me back and let me know their diagnosis.
Blend mode actuator.
Hmmm, the EXACT thing I told them it was 5 months ago.
They are working on replacing it as we speak.
So...long post short...OP, that's what the problem is.
After I was told the clicking noise was normal, I learned to live with it, because it didn't bother me that much.
That was back in April.
Since then I did find out that when it was in bi-level mode, even with the fan on its highest setting, little or no air would come out of the dash vents. It was coming out of the defrost vents.
A-ha!
Something concrete I could show them.
So this morning I take it in for it's 10,000 service.
I show them this.
They call me back and let me know their diagnosis.
Blend mode actuator.
Hmmm, the EXACT thing I told them it was 5 months ago.
They are working on replacing it as we speak.
So...long post short...OP, that's what the problem is.
Last edited by JPJR; Sep 3, 2013 at 03:04 PM. Reason: added text
Pro
Joined: Aug 2003
Posts: 620
Likes: 45
From: Raleigh NC
Driving to work this morning, I hear the ticking again.
So I switch it to bi-level to check the airflow.
Fan on highest setting.
Some air is coming through the dash vents, but not as much as I would have thought.
I know it is splitting the flow between floor and dash in this mode, but I thought there'd be more.
Oh well.
I'll have them check it again at my next oil change.
Added bonus...now my seat rocks. Not sure what they did to get that started. OY.
Safety Car
Joined: Dec 2006
Posts: 4,642
Likes: 9
From: Dalllas/Ft Worth Area TX
Hey guys....
Hey guys, that is a "stock answer" by stealerships, that response has been quoted numerous times on the CF. Any thing to get you to go away!
Pro
Joined: Aug 2003
Posts: 620
Likes: 45
From: Raleigh NC
This morning, I decided I wanted to just cruise into work with no radio, just enjoy the ride.
Tick tock tick tock tick tock.
I will be taking it back for the 4th time to address this.
1st time: "it's normal"
2nd time:"that's not right...replaced blend door actuator"
3rd time: after the ticking came back..."it's normal"
This time the sound is coming from behind the passenger side dash.
Maybe there's another actuator on that side.
I can make it do it by fiddling with the passenger climate controls.
I emailed the assembly plant via their website but never heard back.
Didn't really expect to.
They are probably so deep in C7 now that they don't really care about C6 issues anymore.
Other than this, and the rocking/popping seat, I absolutely love my car.
These are my only two complaints.
Tick tock tick tock tick tock.
I will be taking it back for the 4th time to address this.
1st time: "it's normal"
2nd time:"that's not right...replaced blend door actuator"
3rd time: after the ticking came back..."it's normal"
This time the sound is coming from behind the passenger side dash.
Maybe there's another actuator on that side.
I can make it do it by fiddling with the passenger climate controls.
I emailed the assembly plant via their website but never heard back.
Didn't really expect to.
They are probably so deep in C7 now that they don't really care about C6 issues anymore.
Other than this, and the rocking/popping seat, I absolutely love my car.
These are my only two complaints.
Melting Slicks
Joined: Mar 2010
Posts: 2,861
Likes: 8
From: DC Metro
DC Area Events Coordinator
Cheers,
JB
Racer
Joined: Mar 2013
Posts: 437
Likes: 40
From: Vero Beach FL
I've got a 13 GS with the same issue but mine has had the blend doors and the actuators replaced. Mine also makes the noise when the car is not running and the FOB is not in my pocket. I can hear it hours after parking the car.
