Harmonic Vibration, Balancer ??
05-24-2018, 09:42 PM
#1
Safety Car
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Harmonic Vibration, Balancer ??
Anyone had to have their Harmonic Balancer replaced in their C7 ?
I searched and only found C6 info on Harmonic Balancer replacements.
Just a guess right now on my part.
But I'm getting a slight high low rhythmic vibration when cruising steady.
It's not a strong vibration and mostly noticeable when first taking the car out for a drive.
After it's been driven a while it's barely noticeable and "almost" goes away.
I have the A8 so naturally thought it might be the Torque Converter.
But it's rhythmic and does it in Manual and/or any gear with steady highway cruising.
I don't think it's my wheels/tires since I have 2 sets and it does it with either set on the car.
Any one have an idea what it might be.
I searched and only found C6 info on Harmonic Balancer replacements.
Just a guess right now on my part.
But I'm getting a slight high low rhythmic vibration when cruising steady.
It's not a strong vibration and mostly noticeable when first taking the car out for a drive.
After it's been driven a while it's barely noticeable and "almost" goes away.
I have the A8 so naturally thought it might be the Torque Converter.
But it's rhythmic and does it in Manual and/or any gear with steady highway cruising.
I don't think it's my wheels/tires since I have 2 sets and it does it with either set on the car.
Any one have an idea what it might be.
05-24-2018, 10:10 PM
#3
Le Mans Master
Balancer would have avisible wobble and vibration would increase with engine speed. In or out of powertrain warranty? Road testing with electronic vibration analyzer or reed tach will help identify where to look.
05-24-2018, 11:46 PM
#4
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Will pay more attention to that while steadily increasing speed
05-25-2018, 12:39 PM
#5
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Took it for a drive and put it in Neutral at 80mph.
It had the Very Slight harmonic vibration, but noticeably less than normal and guessing that rules out the TC.
Maybe it's the drive shaft out of balance ?
Checked the Harmonic Balancer and no visible wobble.
The vibration is rhythmic, but the rhythm did not seem to change according to speed except that it's not noticeable around town.
Or cruising back roads between 40-50mph
One other thing I meant to mention is it's more noticeable in cold weather until the car is driven a while and totally warmed up.
Also passengers don't seem to notice it.
And I had it at the Dealers beginning of May to have the Tech take it for a spin.
My intention was to get the Trans flushed, and after we went for a drive with the Tech driving it, in his opinion it was fine.
He's done the flush on some C7's he felt needed it, so I'm trusting his judgement on that.
Still all guess work on my part and warranty is good until Oct 2021
It had the Very Slight harmonic vibration, but noticeably less than normal and guessing that rules out the TC.
Maybe it's the drive shaft out of balance ?
Checked the Harmonic Balancer and no visible wobble.
The vibration is rhythmic, but the rhythm did not seem to change according to speed except that it's not noticeable around town.
Or cruising back roads between 40-50mph
One other thing I meant to mention is it's more noticeable in cold weather until the car is driven a while and totally warmed up.
Also passengers don't seem to notice it.
And I had it at the Dealers beginning of May to have the Tech take it for a spin.
My intention was to get the Trans flushed, and after we went for a drive with the Tech driving it, in his opinion it was fine.
He's done the flush on some C7's he felt needed it, so I'm trusting his judgement on that.
Still all guess work on my part and warranty is good until Oct 2021
05-25-2018, 03:18 PM
#6
Naples FL
Took it for a drive and put it in Neutral at 80mph.
It had the Very Slight harmonic vibration, but noticeably less than normal and guessing that rules out the TC.
Maybe it's the drive shaft out of balance ?
Checked the Harmonic Balancer and no visible wobble.
The vibration is rhythmic, but the rhythm did not seem to change according to speed except that it's not noticeable around town.
Or cruising back roads between 40-50mph
One other thing I meant to mention is it's more noticeable in cold weather until the car is driven a while and totally warmed up.
Also passengers don't seem to notice it.
And I had it at the Dealers beginning of May to have the Tech take it for a spin.
My intention was to get the Trans flushed, and after we went for a drive with the Tech driving it, in his opinion it was fine.
He's done the flush on some C7's he felt needed it, so I'm trusting his judgement on that.
Still all guess work on my part and warranty is good until Oct 2021
It had the Very Slight harmonic vibration, but noticeably less than normal and guessing that rules out the TC.
Maybe it's the drive shaft out of balance ?
Checked the Harmonic Balancer and no visible wobble.
The vibration is rhythmic, but the rhythm did not seem to change according to speed except that it's not noticeable around town.
Or cruising back roads between 40-50mph
One other thing I meant to mention is it's more noticeable in cold weather until the car is driven a while and totally warmed up.
Also passengers don't seem to notice it.
And I had it at the Dealers beginning of May to have the Tech take it for a spin.
My intention was to get the Trans flushed, and after we went for a drive with the Tech driving it, in his opinion it was fine.
He's done the flush on some C7's he felt needed it, so I'm trusting his judgement on that.
Still all guess work on my part and warranty is good until Oct 2021
05-25-2018, 05:07 PM
#7
Le Mans Master
It could be exhaust resonance or something grounded. Try to not if its rpm related. Note rpm when it most noticeable. Then drive in different gears at same rpm and see if it repeats. If it does talk to dealer about possible correction.
