hatched91

Hey guys, approximately one month ago, i purchased a 05 cts-v. It has nearly 30k miles, and one engine mount was shot, and the front diff mount was shot. I went ahead and replaced the motor mounts and trans mount with creative steels polyurethane ones, and the diff mount with creative steels bushing. At the same time, i also removed my shifter (found the bushings half backed out), replaced them and performed the "short shift mod". May I say, wow, what a difference!! so much more driveable!

However, before replacing the mounts, i noticed the car rocked side to side when at idle (usually after a mintue or two at idle); as if it had an aftermarket camshaft. I figured replacing the mounts would fix this, but obviously it did not. Also, I noticed that when i jab the gas pedal multiple times at low speeds, i could still hear some clunking going on in the front and rear of the vehicle.

Are there any other common trouble areas that would cause either of these symptoms? Such as bad subframe bushings, etc? I do not think the rocking is due to the engine is misfiring, because it seems smooth and solid and has no CEL's.

Thanks for reading my long post

JOHN STEPHENS

I have replaced everything but the diff bushing, i have it just havnt installed it yet. I believe from my experiences and the things i have read we will never get the clunkiness out of the stock drivetrain. You have to think when the engineers at cadillac were designing this car the were thinking luxury over performance. Point proven with the awesome rear ends they supplied us with. They used lots of rubber to keep noise down and limit vibration, which in return provides more "clunkines". By no means am i bashing the car bc i love mine. Just my .02 cents.

my plan to get rid of clunkiness is do a 8.8 or 9" rear end!

SSmokd U

I am having the same problems. I have not replaced the motor mounts yet but have done everything else. I think a lot of my issues lie in the driveshaft.

hatched91

I did some research and apparantly, this is just "the nature of the beast". After sorting through a bunch of "rocking jokes", I found the rocking is present from the factory.

The clunking in the front should definitely not be present. The rear clunking could be a diff on its way out, since mine whines like a SOB.

How can you tell if a carrier bushing is shot? Mine flexes, but like any bushing, its difficult to determine good working order by visual inspection.

punishmentcycle

iTrader: (6)

if its whining then start saving for a gen 4 diff..mine whined bad and blew not long after.. also it a v8..its gonna rock a little. as far as the clunking its a mix between the driveshaft bearing and play in the diff.. these diffs have a lot of play..even the gen 4's

KamaSutra

Sounds like the majority of the left over clunk is probably due to the stock dual mass flywheel.

SSmokd U

Last time mine was off the ground I did notice an extreme amount of play in the rear diff. Guess I need to think about upgrading soon, too.

hatched91

Granted I am in school, finances are an issue. I will probably just replace the rear diff with a gen 1. I don't drive aggressively much, so it should suffice for the next 8 months.

lollygagger8

iTrader: (7)

Sure sounds like engine mounts to me. Loose bolts maybe? Unless you really do have a cam in it and don't know it?

hatched91

I've owned a two bmw's, mustangs, and a couple of camaros. (i trade cars off often ) none of them have rocked at idle, and all have been v8's. So i agree, i'll double check the bolts, but i am fairly positive none are loose. guess i'll find out

hatched91

the bolts have been checked, all is tight. Another symptom i have noticed, is that when the engine is cold, the start up is VERY rough, as well as shut down. I know i have polyurethane MM and trans mount, but it's much more rough than it should be. It's almost as if the engine is misfiring when starting. As stupid as this sounds, i hear, "crank...crank...crank..pause...fire". I guess i'll have to take a video and post it up. Could my dual mass flywheel possibly be shot?

Andy0x1

Just to chime in here; I have an 05-V, with a cam, headers, exhaust, etc...

I installed a GeForce Axel a few months back with the hopes of it fixing my wheel hop. It didn't.

More recently I bought a BMR Wheel hop kit which included cradle spacers, subframe bushings, and a trailing arm brace.

In order to get my exhaust to clear the bar, I used a floor jack to bend the exhaust out of the way.

Since doing this, I got some nasty noise durring even light acceleration. Put it on the lift and had someone watch from under the car while I loaded the clutch...

Ended up being the catalysts hitting the frame. After using a pry-bar and an extension pipe to pry the catalysts away from the frame, it fixed that noise but:

I'm still getting driveline clunking even just pushing the clutch in at the end of a gear; I'm not sure if it's the exhaust hitting the sub-frame or brace, or if its the subframe unloading due to the BMR spacers being present. It's never made this noise before.

The BMR kit is coming off, but as long as I'm going through the trouble, I'm considering Specter Werkes bushings to replace the TSB ones.

Not sure if its going to be a waste of money or not. I just can't stand the wheel hop (!)

Hope the clunking goes away with the removal of the BMR kit.

Andy0x1

Oh and trying to drive below slightly below 1300rpm results in clunking now too. Used to only buck below ~1100 with no load.

hatched91

if its a clunk you feel in the drivetrain, then its probably mount related. If its a clunk you feel in the body, then its most likely exhaust. It should be simple to find it, just take it to an exhaust shop, and have them check it out. That way, they can make adjustments if the exhaust is the problem. I would think if its drivetain, it would feel severe, whereas exhaust would just be more of a sound than feel.

Derek98z

iTrader: (55)

So you only have 30k miles and these problems? Please do post a video to see if we can help

DMM

I have the same problem after installing the CS mounts...feels like the exhaust is touching the frame but its not. It especially feels like total **** on cold startup and anytime during low RPM's. I have contemplated going with the solid on the drivers side and a factory mount on the passenger side but don't know if it would help or hurt it.

I am honestly thinking that replacing the factory mounts every 10k miles would be better off than dealing with this.

Has anyone tried a solid drivers and factory passenger mount combo?

hatched91

glad to hear that i'm not alone. It might just be a side effect of the stiff CS mounts. I'm going to run a scanner on my car next week and see if there are any misfires or fklc.

JNR_Design

iTrader: (3)

The LS6 will have a rougher idle than the LS2, so think it would have more of a tendency to 'rock' the car...Unless mine (LS2) has a rough idle, the car does not rock, even if I rev it up...Well, it may slightly but not enough to notice. This is with oem mounts that I think are on their way out...I am thinking once I put the CS poly's in (have them just need to install), then it will probably 'rock' some more under load/movement, but this car (chassis) feels tight enough to not transfer too badly...Remember these are unibodies though, so changing to poly will be more noticeable, as for transferring vibes and such; where as my chevelle, being a full frame, you don't notice it near as much...That thing rocks real good when you rev (have poly mounts), but it is a pretty wild engine too in a good way though...I think, as mentioned, you'll always get a degree of that going on with a typical RWD (config) V8 or V6 engine; probably even a 4 banger too (not transverse mounted) as it's just the nature of it to want to "spin" over and the energy has to go somewhere, if that makes sense...

hatched91

Yes, it makes sense. If there was a lopey idle, it would cause a rock. However, since our oem engines do not have a lopey idle, the angular force (clockwise?) should be constant (at constant idle). This would just create a constant push on the passenger mount, and a constant pull on the drivers mount. So, when my car is rocking as if it were in high winds, or as if a person was rocking it with their hands, it spikes me as if something were wrong.

9t8z28

iTrader: (19)

X2! Thats the issue