Motor Mounts

[Scott R]

I don't have access to PET right now so I can't look up the proper orientation of the motor mounts, can the be flipped 180 deg and still be installed?

I just picked up my 951 from the shop today, its been there two months and they could not find my ongoing suspension/ stopping and popping noise. So now I am backtracking all of the repairs that I have ever done to see if I could have done something wrong. This noise may not be suspension related since their are no driveability issues at all. But when the cars weight transitions from front to back and back to front something attached to the chassis POP's. You can feel it in the seats and floorbaords, but you can' tell from where. This is the second shop that has now confirmed that EVERYTHING in the suspension is tip top. IN fact everything down to the castro blocks is new.

So now I am thinking that it may be the aftermarket mounts that I installed when I purchased the car. Could the be installed incorrectly? I remeber that they fit into a housing......

[SoCal Driver]

If your engine mounts have collapsed you will hardly be able to stick your fingers between the crossmember and the oil pan.

Check the trans mounts too.

Could the chassis be cracked? Or the rear suspension bars loose?

[Scott R]

Originally posted by SoCal Driver
If your engine mounts have collapsed you will hardly be able to stick your fingers between the crossmember and the oil pan.

Check the trans mounts too.

Could the chassis be cracked? Or the rear suspension bars loose?

Do you think its possible to have a motor mount failure and not have the traditional "vibration" thats usually associated with it?

The trans mount looks intact visually, I wish there was a better way to check that other than burning the hour dropping the tranny.

The rear bars check out, I have had the car on a dyno recently to try and diagnose this problem, using camers underneat we could not see any excessive play in the rear suspension. I would hate to gut the rear suspension for a diagnoses.

[SoCal Driver]

Grab the trans and give it a good shake. Also look at the clearence between the bottom of the back of the torq tube where it goes over the rear suspension torsion tube.

Could be the top bushings on the struts or even the struts themselves.

Check the strut top bushings first.

[Scott R]

I proactively did new strut mounts earlier this year when I changed the suspension over to coilovers.

This transmission idead intrigues me, about how much clearence should be between the tube and the torsion assy. Also how much movement is execessive, I can move the transmission from side to side a bit.

[SoCal Driver]

Hmmm... Coil overs.

Check to see if the end of the springs are seated properly. Look closely for signs of movement.

[Scott R]

None that I can see, I did however notice just now when I was checking the trans mount (which appears to be in great shape) that the rear sway bar looks to be moving left to right in its bushings. There is a clean are left of each bushing where it moving. The drop links are intact, maybe its a bad bushing, I guess I could drop the rear sway bar out and drive it like that to diagnose.

BTW it was doing this before the coil over swap, which included new 968 control arms, front and rear Koni coils, new castor blocks, and new strut mounts.

I also forgot to add that it happens more frequently when the car is warm.

[RichMason]

Scott,

Did you get this resolved yet? I have eerily similar noises. I know that I have a bad front sway bar link but I'm also thinking that my transmission mounts are bad. I have some vibration in my stick shift, the shifter moves transitioning on and off throttle and I have some play in the drivetrain coming off throttle that makes the car buck a little bit. My clutch is new... Pelase let me know if you find any definitive tests for the transmission mounts.

[Scott R]

Not as of yet, and as SoCal stated I may have a chassis break or some warping. It goes in tuesday to a specialist to have the chassis sounded with some special tool that uses acoustics, with magnetic samplers attached to certain chassis points to find problems.

I have been able to isolate my noise to the front right wheel as it now makes the POP going over speedbumps. Seeing as how the ball joint and everything else is new, I am leaning towards some sort of stress fracture.

[SoCal Driver]

Stress fracture. Not good.

Checked all the bolts and mounts?

Checked the wheel bearings? Large rear nut is tight?

Oh well...

[Scott R]

Checked, and rechecked. In fact the wheel bearings are new and the strut mounts were new when I installed the coil overs last summer.

[SoCal Driver]

Not good. Not good.

Keep us posted on your findings.

[Scott R]

Will do, I think this may be some existing accident damage from some point in my 951's life. When I got the car the castor block was only being held in by one cross threaded 5/8ths bolt. And the passenger tire had been stuffed into the fender well. I did the body work and had the fender repaired, but I think it was a bigger issue.

[Tervuren]

A necromancer is bring this thread from the grave, wondering, what was it? In nine years there was no response.(I was searching for fingers between cross member to see if I had to do engine mounts while I'm in there with the suspension apart.)

[kfanazini]

These two guys had over 14,000 posts between them. That was in 2003, I was a lot younger then.

[John_AZ]

Originally Posted by kfanazini

These two guys had over 14,000 posts between them. That was in 2003, I was a lot younger then.

Actually...

"Ah, but I was so much older then
I'm younger than that now"

Bob Dylan
My Back Pages

[nightheart]

It's nice to see Socals name again. Evertime I searched for an answer to a problem I'd find one of his posts.