10-03-09-001: Vibration/Pulsation/Thrumming TSB (FIX)

[GotMyG8V8]

I absolutely love it. The service writer even agreed that the vibration was only 90% gone. And he said he was curious to see what was really causing it. I mentioned the TSB and he said the tech looked at it too and didn't do it because he felt that my blizzaks might have been causing the vibration, which is garbage. He was cool about it though, said that if I wasn't happy driving it I could drop it back off and he would drive with me and see first hand and then do what they had to do. Yes the moan I was hearing was noticeably better, but not gone, so the wheel hub was obviously bad. HOWEVER, how could you not notice there is still a moan present when driving the car. And even more so a vibration. Geez my girlfriends cobalt has less vibration in it! lol

[SpeedRacerX]

OK - up to this point, dealer said they did everything on the TSB, except for the propshaft.

So, on Wednesday, I get my car back after the motor mounts were swapped. Still pulls left. Still have some wheel/tire/steering wheel shake. And after a nice road test cruising at 70 mph on Thursday evening, the phasing vibration is STILL there. Actually, I knew it would be because it's obviously coming from the driveline.

I call the dealer Friday am to let them know that the vibration is still there. They say they will order the propshaft and will call me back. They get back to me a few hours later and tell me they talked to GM and they will need my car for 2 days to get all the measurements and readings GM needs before they will OK the propshaft exchange!!!! WTF! Really? What have they been doing with my car during the 3 or 4 visits? I told them 5 times that the TSB was very specific that they had to follow these steps in order for GM to approve the propshaft. I'm beginning to lose patience.

So, I'll try to get my car to them this coming week and let them do what they should have been doing for the last 1-2 months. Hopefully they can exhaust their options and get all the readings they need to justify the propshaft, get it ordered, and get it swapped out.

Sounds like I'm at this for another 2 weeks until it's resolved.

[WickedMom]

The motor mounts are just to address a vibration in AFM mode. Not the complaint most of us have...
The measurements shouldnt take 2 days to do... more like an hour.

[SpeedRacerX]

The motor mounts are just to address a vibration in AFM mode. Not the complaint most of us have...
The measurements shouldnt take 2 days to do... more like an hour.

Yes I know what the new motor mounts were meant to cure and no, it's not the problem I have. I think the dealer wasn't listening but they will be on Monday because my patience has worn thin.

I have no reason to doubt what you say about the hours versus days; let's hope I'm pleasantly surprised.

[Badco]

I have this issue currently. I noticed it today on the highway. Low frequency, rythmic "thrums" and it wasn't the AFM kicking in. It's headed to the shop Monday. We'll see what happens then!

[WickedMom]

my freakin mechanics wife HAD to go have a baby in the middle of my diag on this. He comes back monday...

[Mike P]

my freakin mechanics wife HAD to go have a baby in the middle of my diag on this. He comes back monday...

She could have held it..... lol



...

[VQ35DE]

my freakin mechanics wife HAD to go have a baby in the middle of my diag on this. He comes back monday...

You should have told her to WAIT !

[Adam]

Thanks for the post. It has been on my service write up since the 24 mile mark. still have the issue... 6 services later, I am seeing this and I think it sounds just like my issue.

[Adjusted35]

Thanks for the post. It has been on my service write up since the 24 mile mark. still have the issue... 6 services later, I am seeing this and I think it sounds just like my issue.

Check out my "GM Balanced Driveshaft" thread in the G8 drivetrain section.

There's an after-install review or two of the Dynotech balanced replacement shafts that GM is dropping into the G8's which have resonance at 46Hz (once you convince your dealer to put on the vibration sensing equipment and drive 65 for a mile or two!)

Good luck...if you can get them to bend, it will make your world a nicer place...total elimination of all drivetrain vibrations. Very nice.