Cadillac CTS-V - 06 CTS-V Motor Vibration Problems???

I bought this 2006 CTS-V for my wife about 6 months ago and I am having problem after problem, I feel I have worked on more then I have drove the damn thing.

The problem I am having now is that I just put some UMI motor mounts in to try and get rid of the clunking and strang noises. Well after the install I now have a violent vibration at around 2000 RPM and when driving it at 1900-2400 RPM it feels like it will vibrate right off the road it is so bad. As of right now, I am suspecting the harmonic balancer just because when idleing it was not very true when rotating. I am also thinking that the clutch or fly wheel might be the problem but don't really want to pull the trans for nothing.

What do you guys think it could be?


P.S.
I have taken to the 1/8 mile drags one time and the best I could ge out of the thing was 8:68@87 with major wheel hoop at launch and evey gear change. Any advice on upgrades would be great.

Don't know what the problem is..but a friend of mine same year just picked his car up from have the same mounts installed and is also saying he has terrible vibrations...maybe it's an ls2 problem?

So, does anyone have a solution for this problem?

P.S.
I have taken to the 1/8 mile drags one time and the best I could ge out of the thing was 8:68@87 with major wheel hoop at launch and evey gear change. Any advice on upgrades would be great.

This will get rid of the wheel hop.

http://shop.gforce1320.com/product.sc?productId=53&categoryId=22

My bad vibration on umi mounts is @ 850 rpms and I idle at 750. Driving I dont' hit it but stop and start it is annoying. I suspect the craptactular flywheel on mine.

order up some creative steel motor mounts...either way, youre gonna need em

I think you're right to look at the harmonic damper and the flywheel.

If it wasn't "very true" then I would have serious concern. If you naturally aspirated, summit has a replacement for under $200.


Also check your trans mount and the driveshaft up and down.


I had a C5 and a rear upper a arm bolt fell off while I was cruising and between 45 and 55 I really thought the car was about to fall apart and my ass would be dragging on the pavement.

i had the vibration problem. found the ring on the balancer walked. replaced with an ASP under drive and no more problems.

Could be either the balancer, flywheel ,or both... I'd replace the balancer first if you can see some lateral movement

Is this the balancer you are telling me about? http://www.summitracing.com/parts/ACF-12603916/

Also, it is a motor vibration and not drive line because I feel it in natural.

I think you're right to look at the harmonic damper and the flywheel.

If it wasn't "very true" then I would have serious concern. If you naturally aspirated, summit has a replacement for under $200.


Also check your trans mount and the driveshaft up and down.


I had a C5 and a rear upper a arm bolt fell off while I was cruising and between 45 and 55 I really thought the car was about to fall apart and my ass would be dragging on the pavement.

I thought the 06-07 did not have the axle problems that caused wheel hop?This will get rid of the wheel hop.

http://shop.gforce1320.com/product.sc?productId=53&categoryId=22

Anything that will work on a 2005 Corvette will work for you verhicle. Depending on if you want to underdrive it or not, will dictate which part.

Stock diameter is 7.5 inches. Summit makes a harmonic balancer that I think will be better than stock and it's ~170 Trick flow also makes one near same price.

ATI part number is 917266 which I know because that's the one I need to order for my project.

Do you think this will do the job? http://www.jegs.com/i/Pro+Race/439/34261/10002/-1Anything that will work on a 2005 Corvette will work for you verhicle. Depending on if you want to underdrive it or not, will dictate which part.

Stock diameter is 7.5 inches. Summit makes a harmonic balancer that I think will be better than stock and it's ~170 Trick flow also makes one near same price.

ATI part number is 917266 which I know because that's the one I need to order for my project.

I have the same problem but I'm leaning more toward flywheel

Do you think this will do the job? http://www.jegs.com/i/Pro+Race/439/34261/10002/-1

From everything I know about the matter, yes.

Honestly, that's the same description summit uses on the summit brand balancers, looks pretty close too. Summit balancer is ~40 bucks cheaper.

Get a tiny mirror and examine the front of your balancer very carefully. My bet is you will find many small cracks in the rubber. Seen stock balancers slide back into the timing cover several times now, mostly on vettes though. They definitely fail over time and I would replace it no matter what if I was in your position just to eliminate that possibility.

Just curious, how many miles are on the car?

Ok, I pulled the balancer off and the rubber is in bad shape, so I had a 04 Vet motor here that I kind of forgot about till I was reading this in my lower garage. I pulled it off that one and installed it and I still have the vibration but not as bad, barely any change.

I am having a hard time understanding how and why the flywheel / clutch assembley gets out of balance. What am I missing here???

You sure the balancer you installed is good?

You sure the balancer you installed is good?

I hope it is, it looked almost brand new compard to the one I took off, the rubber looked perfect and it turns true unlike the one I pulled off, but I still have a vibration. :bang:

Check spark plugs and wires. Very cheap option and I've heard of that fixing vibe problems. Most ppl are due for that maintenance anyways

Doubtful its randomly picked up a miss when he changed motor mounts...At this point it could be your flywheel, but I think you would have felt it with the old mounts too. Possible that one of the weights is sticking on the flywheel.

Dose it vibrate when the clutch is drepressed and you rev the engine while not moving? Or, does it only do it driving?

OK, so far I have changed the balancer, plugs and wires. I am still having a pretty good vibration at 1900 - 2700. The vibration is still there when clutch is in not moving or moving. It is not the drive line, this is a motor issue.

So can someone tell me how the flywheel gets out of balance?

Also is a LS7 flywheel and clutch a good upgrade or is there a better way to go?

I don't know much about the dual mass flywheels other than they suck. LS7 clutch/flywheel is one of the consensus upgrades if staying under ~ 450 wheel and you don't drag race a lot. At least you're narrowing down the problem. Very interested to see it fixed.

Is there good clearance between the bellhousing and body of vehicle? Also, around the back of the heads?

Can you get a video of the motor bay when this happens (maybe have someone rev it)?

Is there a flywheel you can use to replace the dual mass style that will work with the stock clutch and throw out bearing for people that are planning on staying mostly stock?

The flywheel can get out of balance of one of the springs fail..weights move outward as the rpm rises (dual mass) . It could very well be your problem...or the truck motor is just trying to jump out of your car and into a pickup :-)

Is there a flywheel you can use to replace the dual mass style that will work with the stock clutch and throw out bearing for people that are planning on staying mostly stock?

I have not heard of anyone doing "just" a flywheel. They usually get the ls7 package that has a new clutch and flywheel together.

If you go to single mass flywheel, you get the katech spacer to use your stock throw out bearing.

The LS7 throwout will work and you will not need to get the spacer with this one.

Did you check your motor mounts?

Completely sounds like the DM flywheel to me. I changed mine out and a lot of the vibrations went away along with the huge shutter at shut down... and this is with stock motor mounts on a 100k car. There are still some slight vibes at idle, but I'll attribute those to the motor mounts and nature of the engine.

Did you check your motor mounts?

As in installing the new UMI mounts correctly ?

I installed my UMI mounts a few days ago, and I also get an engine vibration. I can feel it at all rpms, but mostly 2500+. I'm thinking its the flywheel also. and I also get the vibration at 800-900 rpms that feels like the car is going to shake apart (feels more like a typical engine grounding out), but I'm guessing that's a result of the almost solid design of the mounts.

I think a lot of this is the nature of the mounts, i just put them on my car too (w/32000 miles, vibes are noticeable at idle, if bogging the engine a little, and in that 1900-2500 rpm range. although on the highway i can't tell the difference.

I have not had a chance to dig around on the car any, the balance does appear to have a slight wobble to it when running, but i don't know what new looked like either.

I installed my UMI mounts a few days ago, and I also get an engine vibration. I can feel it at all rpms, but mostly 2500+. I'm thinking its the flywheel also. and I also get the vibration at 800-900 rpms that feels like the car is going to shake apart (feels more like a typical engine grounding out), but I'm guessing that's a result of the almost solid design of the mounts.

This is why I asked UMI if they could make the mounts with softer rubber bushing vice the solid poly bushings in their introduction thread...and I was labeled an asshole for doing so. Shocking that everyone finds them too rigid for installation in a Cadillac.

This is why I asked UMI if they could make the mounts with softer rubber bushing vice the solid poly bushings in their introduction thread...and I was labeled an asshole for doing so. Shocking that everyone finds them too rigid for installation in a Cadillac.

I agree, I think regular rubber bushings would be perfect. I'm pretty sure mine came with the part numbers of the Prothane bushings they used. I'll see if I can cross reference them to see what application they are used for and if softer rubber ones are available.

I thought the 06-07 did not have the axle problems that caused wheel hop?

Oh no. GM decided not to correct this. But that vibration complaint makes me wonder. I have a weird noise on take off from a stop that occurs at no other time. I'm going to do UMI motor mounts and CS trans and diff bushing along with the LS7 clutch within the next year. I hope that dumbass noise goes away. I ran my Camaro today while revving with the throttle cable and watched the whole body torque to the driver's side (its got prothane motor and trans mounts). I need my V to be like that.