: Proud new owner of an 07 CTS-V . . . have a question



Redline93
11-03-11, 08:01 PM
Hello Everyone,

I purchased my 2007 CTS-V in September from a dealership in Baltimore, MD. The car currently has 44k miles on the odometer and appeared stock to me when I purchased it. The car has some sort of short throw shifter and I've since been under the car and discovered the car has UUC motor mounts and GForce Anti Wheel Hop axles.

It's been a real treat to drive except for one issue that two Cadillac mechanics haven't been able to diagnose properly: There's a serious exhaust leak-type sound that fills the cabin under acceleration. You cannot notice anything when you start the car or just letting it idle, and you cannot notice it while revving the vehicle in neutral. The noise only makes itself known under acceleration - and it's to the point where it rattles the interior pieces if accelerating at a measured pace and the tachometer climbs past 3500-4000. If you accelerate with the windows down, it doesn't appear that the car has any sort of "leak." The noise seems to be coming from the front of the car.

The first Cadillac mechanic tried to blame the sound on the UUC motormounts while another mechanic at a different dealership replaced all of my exhaust bolts from the catalytic converter to the back with no success. I'm kind of baffled by this; usually if there's a bonafide exhaust leak, you can hear it when you rev the car in neutral and/or when accelerating. I only hear mine - and it's very noticeable - while accelerating and with the windows up. If I'm in 6th gear doing 65mph and I accelerate, the sound tends to drone a bit as well.

Anyway, it's great to be here. I love the car and I'm ready to learn all that I can about it. Future modifications remain TBD until I can solve this "noise."

Houdini
11-03-11, 08:06 PM
Congrats on the nice purchase. Welcome to the forums! Let's see some pics of your new ride....

Redline93
11-03-11, 08:23 PM
Thanks Houdini. I will snap a few pics this weekend. Best of luck in your search for a V2 as well!

GDPossehl
11-04-11, 08:01 AM
Sounds like it's time for a full exhaust. Headers and a catback system should solve that problem.

Aurora40
11-04-11, 08:08 AM
The exhaust can be kind of close to the driveshaft, the little crossbrace under the car, and the diff housing. Also there is heat shielding down the tunnel it can be close to.

My guess is it is hitting one of those. I wonder if the UUC mounts are allowing too much movement.

Is the exhaust stock? If so, it's one piece from aft of the cats to the tailpipe, so nothing to get loose.

cts-v avino
11-04-11, 08:42 AM
Is it this sound disscussed in this thread?
http://www.cadillacforums.com/forums/2004-2007-cadillac-cts-v-general/239215-ticking-noise.html
Maybe the mufflers were gutted?

j_Son
11-04-11, 09:52 AM
welcome enjoy the V

Redline93
11-04-11, 11:46 AM
The exhaust can be kind of close to the driveshaft, the little crossbrace under the car, and the diff housing. Also there is heat shielding down the tunnel it can be close to.

My guess is it is hitting one of those. I wonder if the UUC mounts are allowing too much movement.

Is the exhaust stock? If so, it's one piece from aft of the cats to the tailpipe, so nothing to get loose.

Hmm I thought the mounts did the opposite by not allowing much movement . . .

The exhaust and the headers are completely stock. And after reading through the referenced thread by cts-v avino I can say for sure that my sound is different. I would love to purchase headers and a cat-back exhaust for the car but I think I'd like to figure this issue out prior to throwing money at an issue that should have a diagnosis provided a reasonable examination of the noise is performed.

I will let you guys know if/when this gets fixed. If anyone has any other ideas please chime in.

After thinking more about it, the sound in the cabin when accelerating resembles the sound of the jake-brake on a tractor trailor.

jcollege
11-04-11, 12:44 PM
If you are close to the DC Metro area I would take it down to Lindsay Cadillac in Alexandria, they know V's there...to say the least!

JimmyH
11-04-11, 01:21 PM
Welcome to the forums and the V!

Headers are not stock. Unless you mean you have stock manifolds.

Redline93
11-04-11, 02:33 PM
Thanks Jimmy! It's great to be here. And I apologize . . . I have stock manifolds on the vehicle. There aren't headers on the car. I live in C. NJ so I would love to take it to Lindsey but I think it's too far.

JimmyH
11-04-11, 03:36 PM
Many a V owner have driven great distances to take their V to Lindsay. Most of their customers will tell you they are worth the drive.

Redline93
11-04-11, 08:57 PM
Many a V owner have driven great distances to take their V to Lindsay. Most of their customers will tell you they are worth the drive.

Duly noted Jimmy; thanks again.

JimmyH
11-05-11, 10:37 AM
Life is a journey, enjoy the ride :D

Aurora40
11-05-11, 02:58 PM
Hmm I thought the mounts did the opposite by not allowing much movement . . .
That's what they are supposed to do, but it doesn't mean they are doing it. ;)