: Vibes at 2300-2600



JFensty
11-02-11, 05:40 PM
I tried the search but no luck. I am getting vibes in between 2300-2600. I just installed new UMI performance mounts and they are great but I can feel the vibes more now of course. I have a stock clutch so I'm assuming its the flywheel. Would the flywheel also cause a shudder/vibe when starting out? Other than the obvious while you are in there comment, has any ran a lightweight flywheel with stock clutch and pp?

CadzillaTN
11-02-11, 05:56 PM
Could you feel the vibes before the mounts?

Lightweight fw isn't going to cure anything unless the stock is completely shot. How many miles do you have?

JFensty
11-02-11, 06:58 PM
I could feel the vibes before, so I knew they were there. I figured some was the mount. 116k with possibly stock clutch. Previous owner took it to dealer for everything incl oil changes but no mention of clutch replacement. Im assuming the stock flywheel is toast. No slippage in the clutch tho.

darkman
11-02-11, 08:26 PM
Other than the obvious while you are in there comment, has any ran a lightweight flywheel with stock clutch and pp?

I am running the UUC Motorwerks lightweight flywheel, which is a manufacured by Fidanza, with a stock CTS-V pressure plate, clutch disc and other components. It works just fine.

That particular clutch disc is not spring loaded since the original dual-mass flywheel provided the spring dampening. Because the single mass lightweight flywheel is also not sprung there is no dampening between the motor and the transmission. This absence of dampening causes no driveability problems but does result in more gear rattle noise if, and only if, the engine is lugged by attempting to accelerate at low rpm (below 1.5k rpm) at low speeds in very high gears.

DougNuts
11-03-11, 10:21 AM
I also have the same vibration, although mine is closer to 2150-2300 rpms. I have replaced the harmonic damper, clutch/pp/flywheel (LS7) and motor/trans mounts (creative steel), spark plugs and fluids with no luck in eliminating the vibrations.

JFensty
11-03-11, 11:08 AM
Is there to check for items that could cause a rough idle or miss that could cause the vibration. Meaning a leaky injector, bad plug, or the like that would not cause the CEL to come on, but cause problems. I have noticed that under load(accelerating in 4th at 50 approx 1800 or 2000 rpm) there is a slight surge or miss. Most times you wouldn't notice. Maybe I'm just paranoid tho.

Cadillac Cust Svc
11-03-11, 01:43 PM
DougNuts,
If you would like to send me your name and VIN I can check with my resources and see if I can help you find answers to this question.
Breanne
Cadillac Customer Service

CadzillaTN
11-03-11, 06:06 PM
Cars get old. Stiffer, lighter, mod this change that equals chance for vibration. Go back and read threads from day one, zero vibrations. Now 1 of every 3 threads is about vibration.

Here's the solution: drive your car to lansing, have them disassemble and replace every part of the drivetrain with stock parts, balance as a unit, drop the body on, and roll out. :yeah:

vcaddy06
11-28-11, 09:45 PM
I'm getting a very similar vibe, but it starts vibrating while in neutral at 1700 rpms and stopped. Ive never replaced my motor mounts since acquiring the car at 31k (now at 53k) and will be very soon. But I've also considered the flywheel/pp/clutch as a cause of the vibes. How fast do the clutches/flywheels generally start to die on these cars?

darkman
11-28-11, 10:00 PM
A skilled and conservative driver can likely get 100k miles before the clutch disc and pressure plate start slipping. However, based on reports on this forum, I suspect the dual mass flywheel can become an issue sooner regardless of how the car is driven.

CadzillaTN
11-28-11, 11:58 PM
I want to blame the stock clutch, but that would rule out guys like doug with the ls7 and the same issue.

I had the same problem, bad clutch vibration. Dealer replaced fw, I was left with a very pronounced vibration btw ~2000-2600...

I replaced the disc and pp, and the specific 2000's vibration is gone but now I have a nice flat vibration so to speak throughout the rpm range. Kind of annoying but it feels so much better than the old clutch I can live with it. I think it's my engine mounts. I firmed them up by filling them with poly, and the current vibration feels just like when I first put in aftermarket mounts after only having stockers for 3+ yrs.... I think the stock mounts just dampen engine vibes very very well.

I noticed when installing the clutch that even when it's all bolted up tight, you can still press on the edges of the pp and the whole assembly moves on the layer of the fw fixed to the crank. I thought I had not tightened down some bolts, but verified it was normal on another stock clutch I had on hand. The point, the stocker is just a heavy, loosely layered turd. When it begins to deteriorate, it gets ugly.



Which brings us back to doug. I really thought the ls7 would be the ticket but if I can't get rid of vibes im not pulling that trigger. I wish he could nail it down.

As an experiment I'd liked to stick a new set of stock mounts in and see how it feels...i bet if you took a brand new v and put aftermarket mounts in it, it would vibrate. Maybe the ticket is stock mounts and a torque cable....

DougNuts
11-29-11, 02:50 PM
DougNuts,
If you would like to send me your name and VIN I can check with my resources and see if I can help you find answers to this question.
Breanne
Cadillac Customer Service

Breanne, I just saw this and will send you my VIN in a minute. Thank you.


Which brings us back to doug. I really thought the ls7 would be the ticket but if I can't get rid of vibes im not pulling that trigger. I wish he could nail it down.

As an experiment I'd liked to stick a new set of stock mounts in and see how it feels...i bet if you took a brand new v and put aftermarket mounts in it, it would vibrate. Maybe the ticket is stock mounts and a torque cable....


I haven't been working on the Caddy lately.:thepan: I picked up an old Civic and have been repairing and modifying it. I'm guessing I'll tear into the V after the first of the year.

Lately, I have been thinking like you about the mounts. I'm mulling over buying new stock motor mounts and a new stock transmission mount and see if the vibration goes away. On the other hand, I don't really want to do the motor mounts again. :)

I also want to get the LS7 flywheel/PP balanced, but that's hard to do without the motivation to pull the transmission. :D

I should finish repairing the Civic this week and then once we're through the holidays, I will tear into the V and we'll see where that gets us. :thumbsup: