Cadillac Owners Forum banner

1 - 8 of 8 Posts

·
Registered
08 CTS DI
Joined
·
2,301 Posts
Discussion Starter #1
Symptoms: Sudden onset of a fine vibration felt through the car (you know your car so when it happens you'll notice it), followed by onset of a bump in the seat area to the center of the car that might make you suspect the drive shaft carrier bearing. As the mount worsens, the sensation localizes to the front area of the car. By that time a regular and variable vibration sets in that is regulated to a degree by A/C compressor cycling.


I watched the video on youtube regarding this procedure and decided to tackle the driver side first since it was the toughest. I have since discovered that specifying rear wheel drive, or AWD is important because the two use different mounts which work with different engine cradle assemblies. Both mounts were difficult to remove and took most of the day thinking and wrenching to get them out.

For the driver side, the starter and catalytic converter has to be removed following supporting the subframe and removing the front wheels and the felt dust shield on the inside of the wheel well (not the plastic liner). Support the front end of the oil pan with a piece of 2x4, or equivalent between it and the jack, unbolt the bottom of the mounts and carefully raise the engine until resistance is felt.

I don't know about the AWD cars, or those with the LY7 motor, but this only provides limited clearance as you will discover. The driver side engine mount bracket has to be unbolted next after which the assembly can be wiggled out and off of the car. Reinstallation of the new mount, pre bolted to the bracket will be a challenge but it will go back in place.

On to the passenger side which has less to remove, but is only slightly easier. It was at this stage that I discovered by a blessing of an incidental, that the upper stud on the RWD mounts can be screwed out of the mount, not so on the AWD mount. You would think this would make matters easier, but it's more of a tease. The stud has a molded ring around the mid section that will not pass through the bracket, so it will continue to be an obstacle. I needed a second jack to leverage the right side of the oil pan to twist the motor enough to pry it out.

I was cautious with the engine raise because I didn't know what was actually limiting the upward movement, the transmission, or something on the back end of the motor being compressed between it and the car that could be damaged.

The driver mount was so bad that before I removed it from the car I thought the upper bolt had come loose. I took a before and after picture of the gap between the strut tower brace and the top of the intake manifold. You can see the difference in the pictures. As the mounts wear (likely abrupt rupture on the driver side) the brackets get closer to the shoulders of the motor mount and eventually rest on them (note the shiny areas on the mounts) and that's probably the point where the vibration starts. The driver side mount ruptured and leaked oil, the passenger side was not leaking but was still clearly warn out.

The distance between the mount bracket and the shoulders of the new mounts is about a half inch, maybe a little more and can easily be eyeballed from underneath the car. The distance is a little less between the strut bar and manifold because of the location relative to the mounts.

The difference between the old mounts and the new is night and day. There is no vibration of any kind now and with the music going you might have difficulty telling that the motor is running. It was well worth the trouble and if I have to do it again in the future it will be easier now that I know how to approach it.
 

Attachments

·
Registered
CTS 2008 3.6DI Sport Luxury
Joined
·
1,027 Posts
What mileage?
It is not so difficult as you described. I remember the only think what had to be disconnected (not removed) were a/c lines from compressor. My mech replaced both mounts in c.a. 2h. I described it in separate post here.
 

·
Registered
2009 CTS 3.6L DI rebuilt to FE3 J55 G80 3.42:1
Joined
·
974 Posts
This is a task all Gen II CTS owners can expect to face. I hired it done, wasn't cheap.
 

·
Registered
08 CTS DI
Joined
·
2,301 Posts
Discussion Starter #4
What mileage?
It is not so difficult as you described.
You do realize you are making that statement without the experience of actually having replaced them yourself without any help, if your mechanic installed them. If your car happens to be AWD the clearances are different because of the cradle differences between the two.

2 hrs of literal labor with all of the special tool benefits that come along with being a mechanic is still a good bit of work. I can't justify owning a lift which would certainly have made the job easier. Disconnecting the A/C lines adds the expense of a recovery and recharge fee for the A/C system.

This cost me time well spent plus $140 worth of OE parts. That's roughly an $800 to $1000 job in my neck of the woods so I did well. I can take the change and buy more music equipment. Despite the challenge it posed it was well worth it.
 

·
Registered
CTS 2008 3.6DI Sport Luxury
Joined
·
1,027 Posts
My CTS is RWD.
My mech is my friend. I am always fully involved in all repairs.
My comment is just to clearify that some of things you did are not required, e.g. "For the driver side, the starter and catalytic converter has to be removed following supporting the subframe and removing the front wheels and the felt dust shield on the inside of the wheel well (not the plastic liner)." We didn't do it.
Yes, I had to service a/c but it is nothing more like normal service, which is recommended once every two, three years.

We followed official repair procedure and it was enough. You did it your way and nothing is wrong with that. You are brave I wouldn't do it by myself.
 

·
Registered
08 CTS DI
Joined
·
2,301 Posts
Discussion Starter #6
My CTS is RWD.
My mech is my friend. I am always fully involved in all repairs.
My comment is just to clearify that some of things you did are not required, e.g. "For the driver side, the starter and catalytic converter has to be removed following supporting the subframe and removing the front wheels and the felt dust shield on the inside of the wheel well (not the plastic liner)." We didn't do it.
Yes, I had to service a/c but it is nothing more like normal service, which is recommended once every two, three years.

We followed official repair procedure and it was enough. You did it your way and nothing is wrong with that. You are brave I wouldn't do it by myself.
That's fine, but I'm speaking from my context. If you have no lift and no help and you don't want to depressurize the A/C system, you almost certainly will have to do all of those things, some for the mere benefit of accessibility (no lift remember). I could have left them in place and still been under the car right now. There are two practical ways to get to the proverbial front yard, you can take the front door, or the back door. One path is a bit longer, but you'll end up at the same place.
 

·
Registered
CTS 2008 3.6DI Sport Luxury
Joined
·
1,027 Posts
Good to know alternative ways... Your input is very valuable.
Worth to say we also didn't have car lifted. My mech has old style workshop with repair pit (canal) and simple manual hydraulic lift under the car.
 

·
Registered
08 CTS DI
Joined
·
2,301 Posts
Discussion Starter #8
Good to know alternative ways... Your input is very valuable.
Worth to say we also didn't have car lifted. My mech has old style workshop with repair pit (canal) and simple manual hydraulic lift under the car.
If I ever have a house built, the in floor pit in the garage floor would be golden. It doesn't get anymore simple than that, the lowest of low maintenance equipment.
 
1 - 8 of 8 Posts
Top