Ronnie G

I searched for an engine mount thread and wasn’t able to find one, so I figured I’d start this one!

What engine mounts are your favorite for the 997 and why? I’ve begun looking at replacing mine and there are myriad options to buy.

I want to get some opinions from you guys before pulling the trigger and I’m sure someone else will find it helpful too! Thanks in advance!

Wharf Rat

I went with the Function First. They are stockers with some added urethane. I had a tiny, tiny bit of a vibration with them for a few 100 miles then it was gone. I replaced mine when I bought the car with only 50k and the originals were shot. Made an immediate improvement in handling.

Ronnie G

I’m at 54k on mine and the mufflers are sagging and I’ve got sticky gears between first and second. Hoping some new mounts will help with that and improve the rest of the experience as well

Wayne Smith

I went Rennline for appearance but more importantly tuning capability.

I started full hard figuring I could always go softer if necessary but I probably wouldn't go harder if I started softer. I ended up staying with the full hard. NVH wasn't bad at all. 2010 C4S PDK with 148K miles. Note: I also added the stiffest (black, racing) Function First transmission mounts.

I installed the same motor mounts on a friend's 997.1 and backed down to the softest. His sunroof still rattled badly so we went back to OEM. I've installed stiffer mounts on several friends' cars now without problems except for this one case.

FWIW, I had this same friend drive my car for comparison and he felt no NVH. So YMMV.

bheit1

Just stay with OEM and you won't have to worry about setting of your knock sensor and messing up your timing.

Butzi 997

I installed WEVO yellows on my 997.2 and, over time, had to admit that the impact harshness of the car on road imperfections was pretty uncomfortable. But I'd also added a Bilstein Pro-Kit (Eibach lowering springs and Bilstein B12s) so I didn't know which mods were the problem.

I saw Jack Raby's video of his take on stiffer than OEM engine mounts and replaced the WEVOs because it was the easiest thing to do.
Improvement in the ride was immediate. Take a look-

Petza914

Have RSS mounts on my car. Very happy with them.

plpete84

I highly suggest the OE RS mounts like these - https://rennpart.com/product/rs-engine-mount-upgrade/ They are a perfect happy medium between stock and stiffer aftermarket mounts. Had mine for over a year and very happy. Once the rubber breaks in there is no unwanted resonance in the cabin but you can certainly feel the stiffness over stock. Very happy with my choice.

Khloesdad

+1 on the RSS's. Plus they claim they do not interfere with knock sensor.

TheMurse

Another +1 for the RSS mounts - Installing them was like properly lacing up a sneaker, everything felt tighter and more connected. No unwanted vibration/harshness at idle or under power and 18 months after adding them I've seen no evidence of any change in fuel trims.

BHMav8r

^This^

Rattled my sunroof some but 95% went away after some miles. Have not noticed any knock sensor issues. But I dont redline very much.

Alfnado

Another happy Function First customer here. Went with the trans inserts at the same time. This thread is the first I am hearing of knock sensor issues. I’ve never had them.

Medford997

I just installed FuntionFirst moounts a few days ago. zero MVH and just the right stiffness, super happy. Previously had Rennline mounts with yellow (soft) bushings. They were very nicely made, however too much of an MVH increase for me.

Wayne Smith

You will find this on multiple threads on this Forum. From what I know this can occur at any rpm. Jake Raby has run dyno tests which confirm the phenomenon.

I'll make a couple statements that may or may not be true ...

1. This is not a problem with the knock sensor on GT3 cars which have harder motor mounts from the factory.

2. This is not a problem in 997.2 cars that have DFI (but which can suffer from LSPI which is one of the reasons to change to DI40 oil ... that oil can compromise the catalytic converters but it is not clear to what affect).

Don't take either of the above statements as gospel. I put them here to encourage discussion. Neither is clear to me and I'd love to have more information on both.

idylldon

I have Function First motor and orange transmission mounts and couldn't be happier.

Cheers,
--
Don