Motor Shakes

Lone Ranger · 12-01-2011, 04:20 PM

Hello all,

First post here, first time Cadillac owner. I just bought a 2005 XLR Light Platinum with black interior, 35K miles, 2 year/24K miles of GMPP Major Guard Warranty. I really like the car, came from a Honda S2000 so having so much luxury is nice.

I think that I have a broken motor mount as the engine shakes violently upon shut down and I hear 2 to 3 large thumps as the engine dies. I have shut the engine off with the hood up to see that the thumps coincide with the rocking of the engine upon shut down. The engine is fine, all of them rock a little when turned off. My question is, how common are broken motor mounts? I have read numerous posts on the Covette forums of motor mount issues and they use the same hydraulic filled mounts as the XLR. I have an appointment to see the dealer tomorrow for an oil change and a verification that the mount(s) are broken.

Looking forward to learning more about my new ride.

Hi Yo Silver Away

mtrocket · 12-01-2011, 09:11 PM

I really haven't heard anybody have any problems with the motor mounts... interesting. Let us know what you find out...

Rob · 12-01-2011, 10:11 PM

I have to agree with mtrocket, however I wasn't aware of Corvette owners having engine mount issues either.

I can tell you that years ago, with older cars, one of the easiest ways to tell if a mount is shot...on your own, is to pop the hood, start the car and while you're standing in front of the engine have someone else stomp on the gas pedal a couple times. If it seems like there is excessive movement with the engine, chances are there is a mount that needs to be replaced.

What concerns me here is that you are noticing it when the ignition is turned off which seems odd to me. How is the car running otherwise? Any performance issues at all?

Sent from my ADR6300 using Tapatalk

Lone Ranger · 12-02-2011, 07:36 AM

Just Google Broken Corvette Motor Mounts

Engine performance is great, idles nice, revs nice. I did raise the hood and rev'ed the engine, it lifted about 1/2". With the car in gear, brake fully pressed I slowly gave it some throttle and the engine lifted about an inch. I have it at my local Cadillac dealer now for a Mobil 1 change, and a visual inspection of the mounts while it is up in the air.

I will report back.

Bill

Lone Ranger · 12-02-2011, 10:52 AM

Technician didn't find anything wrong with the mounts. Once the car was back on the ground I asked the Service Department manager to sit in my car and listen to it start, idle, and shut down. Start up was fine, idle you could here a slight thump that he didn't like, and the couple of thumps at shut down he said were normal for the XLR. Once GMPP has the Major Guard turned on in the system, I will take it back in so he can figure out what the thump in idle is. To my ear it is the same sound during idle and shut down, so hopefully he can track it down and fix it.

Bill

ald42 · 12-05-2011, 06:22 PM

welcome and good luck with your new ride,let us know what they find out.