Back in November 2022 I replaced the engine and transmission mounts on my 2011
Cayman
Base. The mounts were shot, especially the engine mount which was torn and causing heavy vibration. It was the original mount. When I got the engine mount uninstalled, I saw the flappy rubber pieces on either side of the center part of the mount and some seriously degraded flappy foam pieces
next
to the rubber These parts are known as the engine mount "stops".
Porsche Engine Mount Stop Genuine Porsche 9A137525701 9A1 375 257 01 9A1.375.257.01 9A1-375-257-01 | Pelican Parts
For the 987.2, they are two piece stop that has a rubber and a foam component bonded together. I believe the 987.1 was originally a thick piece of rubber but was updated to the rubber/foam arrangement. The foam degrades over time from engine movement and such. The foam parts on my original mount were 80% gone. At the time, I did not know that these stops were an integral part to the mount and I simply reinstalled the original stop with just the rubber stop and tossed the foam. I didn't think anything of this as Japanese cars I've worked on the past two decades often had thin rubber flappy pieces and their only job appeared to keep dirt out of the rubber main mount. With the new mount and old stop, the engine vibrations were quite reduced at first. However, after about 2 weeks and as the rubber in the mount loosened up a bit, I started to feel some minor vibrations and general graininess on cold starts and through the rpm range, especially at 1900rpm and a bit 4000rpm whether in neutral or when driving. There was also a faint, but obvious thud on the 1-2 shift. The vibrations weren't terrible at all, but I was surprised that a Porsche would have this amount of vibration/graininess. A few months later after reading forum posts, I figured out that foam part of the stop helps isolate minor vibrations and is integral to the mount.
After about 8 months of putting it off, I finally got around to dropping the engine mount again and installing new stops a few weeks ago. Wow. What a difference those little foam pieces make. Gone is the vibration, graininess, and 1-2 shift thud.
Why did I put it off so long? Because getting the mount out and back in is a royal pain, at least the first time I did it. Getting the bolts out is easy (three from under the car and one through the front engine access). The problem is the two coolant hoses that sit below the mount and the width of the mount itself. It's a seriously tight fit and the first time I did the job, I squeezed, stretched, and manipulated the coolant hoses like hell to get that mount out and back in. I really thought I was going to tear a hose or crack a coolant pipe. One of the coolant lines at the connection point to the motor actually temporarily leaked at its O-ring because I was bending them so hard. This time around though, I worked smarter, not harder. I removed the central lower body panel and removed both cross braces that secure and hold the coolant pipes in place. There's one brace just aft of the engine mount and another one just under the area where the shifter is. On my first removal/install, I only removed the brace aft of the mount. This time I removed both. By undoing the braces, the coolant pipes/hoses, will drop quite a bit more thus giving you a lot more room to get the mount out and back in. It's not remotely as difficult to install once you do this. I had the mount out in 30 seconds and back in within a minute and nothing was being taxed.
So long story short, check those engine mount stops. The condition can be assessed by simply getting under the car and looking. These parts are definitely required if you want to keep NVH at bay. I imagine the foam on the stops only last 5 or so years before it starts to degrade as the middle part of the mount really does torque around a lot.
Great writeup - if only there were a few photos.....
Mine is over 14 yrs old and I'm not noticing excessive NVH. Actually, I'm old-school and I expect a sports car to have Noise, Vibration, and Harshness. So if it's not present I'd probably think something's wrong.
Here is a photo of the orientation stops mounted in the mount (foam side inwards) and a photo of my original mount with 67K miles. You can see that the foam had degraded and was no longer doing anything.
https://cimg5.ibsrv.net/gimg/********.com-vbulletin/719x551/engine_mount_6a67c92c48e08b1d46ddc6973471e1ff164bfac4.jpg
https://cimg8.ibsrv.net/gimg/********.com-vbulletin/1305x905/stop_d80119a95e14f7a6a9cef9a3e1038e36ec7d97b1.jpg
Rather than try to construct an engine stop which may or may not work, I would highly recommend Function First front engine insert with a new oem mount. Orange is the softest of three stiffness.
No thanks for my car. The engine mount stops are an OEM piece and do their job. I don't want to firm up the engine mount more than stock and risk creating more NVH. Yeah yeah, I know, the inserts are claimed to not create any more NVH, but I'm not willing to risk it. I've been modding cars since the mid 1990s and have made the mistake MANY TIMES of believing people's opinions and that such and such mod doesn't create more NVH, drone, etc. Then I did the mod and did exactly the opposite of what many people said it would. So many thousands of dollars wasted on certain aftermarket parts. I've learned race car parts rarely work well on street cars. The OEM engine mount is already pretty firm when it's not torn.
I've had this setup for 3 years now. Yes the first 6 months I had NHV at startup, but after break in of the OEM mount most of that NHV went away. Now, the Function First Orange insert and the OEM motor mount work extremely well. What
LSD
do you have?
I've got about 1000 miles on OEM new
porsche
mount and powerflex yellow engine mount inserts as sold by
FCPEURO
on my 2009
987.2
2.9
My original ones were ripped apart and allowed movment of the engine on and off the throttle.
The inserts and new mount stopped that. There is a slight bit more "rumble" mainly felt through your seat at idle but no untoward vibration or noise with this set up compared to what I had. (Mind you they were old worn out mounts)
Clutch and shifting are much more predictable and smoother.
I have no idea what OEM only would feel like but I can't imagine it being noticably smoother.
