Engine mounts 997

[steve1968]

Want to change my engine mounts to sharpen things up but can’t decide RS or OEM type, car 2005 997 at 82K so expect either will be an improvement .
What are other owners experiences ?

[Discombobulate]

Standard unless NVH doesn't worry you...

[abucd4]

I went OEM at 90k and the difference was huge, don’t regret not going for stiffer at all it’s ideal. It’s amazing how much slop we’re in the originals despite them not having failed, gear change is hugely improved.

RS would likely be fine but obviously be aware vibration will increase. Depends on your use case, mine is a daily so wouldn’t want that all the time.

I’m yet to meet anyone who has managed to stick with RSS unless it’s a track car.

[Adrian-9iafn]

My car has just hit 40k miles and a 2011, I wonder if replacing with factory new would be noticeable, my car has just had all new KW V3, front / rear arms and bushed where there were any signs of wear, so hopefully a tight chassis

[Discombobulate]

Adrian-9iafn said:

My car has just hit 40k miles and a 2011, I wonder if replacing with factory new would be noticeable, my car has just had all new KW V3, front / rear arms and bushed where there were any signs of wear, so hopefully a tight chassis

They should still be OK. One simple test is to look at how low your exhaust tips are (Google for more details). The mounts stretch as they age allowing the engine to drop more.

[RiccardoG]

I replaced mine at 81k miles with the OEM items. Could feel zero difference! Was rather dissapointed and would say to save your money. On the other hand, pleased that the original ones were still good.

Tbf, there were no signs of deterioration, such as fluid leaks or drooping exhaust tips. Just all the chat about people getting them done goaded me into doing them. That and the fact that is they break you're stranded. So, on age alone decdied to to ahead.

Edited by RiccardoG on Monday 16th October 17:06

[Paynewright]

I changed them on my 996 and fitted 993 RS mounts which are metalastic type. The difference was night and day though I didn’t realise how bad they were until the new type were fitted.

Basically, the engine was like a big pendulum on undulating roads and it really unsettled the car. When the car was going down into a bump the engine was still going up!

The new mounts transformed the handling. There is no noticeable change in NVH.

At the time I researched the various options, buying new std mounts and filling the void with PU adhesive was suggested as a way of ‘firming’ them up a bit.

[steve1968]

Thanks for all replies , quite interesting . Got a price from Porsche Nottingham today at £259 each for genuine parts, however as one post said it’s still money wasted if there’s nothing wrong with my current set . May worth taking the left one out and having a look when I have time ?

[Slippydiff]

Paynewright said:

I changed them on my 996 and fitted 993 RS mounts which are metalastic type. The difference was night and day though I didn’t realise how bad they were until the new type were fitted.

Basically, the engine was like a big pendulum on undulating roads and it really unsettled the car. When the car was going down into a bump the engine was still going up!

The new mounts transformed the handling. There is no noticeable change in NVH.

996 C2 at 60k miles.
After replacing with OE mounts, I experienced exactly what you describe.
Gamechanging.

You’re correct in saying the engine is a big, heavy pendulum, but I suspect the old mounts as they stretch and/or lose their damping qualities, and the engine then moves relative to the body at a harmonic frequency that wasn’t intended by the engineers.
The result is an unpleasant front to rear pitching motion that becomes more noticeable at speed over undulating, cresting roads.
The new mounts fixed the issue which I’d previously attributed to either dampers, or in extremis, a geometry issue.

As regards the tailpipes being a gauge of engine mount condition, when the new mounts were fitted, the tailpipes were less than 7mm higher, so in my experience the sag exhibited by the exhaust tailpipes is not an accurate indicator.

[Rich_]

Another 996 owner here. I also fitted 993 RS mounts as well, plus a Powerflex gearbox mount. I did however notice some increase NVH in my case. But it's not my daily driver, so I can deal with it.

[Discombobulate]

Slippydiff said:

996 C2 at 60k miles.
After replacing with OE mounts, I experienced exactly what you describe.
Gamechanging.

You’re correct in saying the engine is a big, heavy pendulum, but I suspect the old mounts as they stretch and/or lose their damping qualities, and the engine then moves relative to the body at a harmonic frequency that wasn’t intended by the engineers.
The result is an unpleasant front to rear pitching motion that becomes more noticeable at speed over undulating, cresting roads.
The new mounts fixed the issue which I’d previously attributed to either dampers, or in extremis, a geometry issue.

As regards the tailpipes being a gauge of engine mount condition, when the new mounts were fitted, the tailpipes were less than 7mm higher, so in my experience the sag exhibited by the exhaust tailpipes is not an accurate indicator.

But they were lower.
If they were not 7mm lower than new then they probably didn't need changing. Not huge I agree, but measurable..

[ATM]

I just bought a pair of these for my 986 but not fitted them yet

Cheap yes

Basically just a solid rubber bush

Shape of the mount is slightly different so not sure fitting is as simple especially on the 986 but thats probably not as relevant on the rear engine cars

You can see on the underside they dont have the square section which helps locate or orient them correctly on the 986 - not seen the 996 setup yet



https://www.ebay.co.uk/itm/234268687380

[Slippydiff]

ATM said:

I just bought a pair of these for my 986 but not fitted them yet

Cheap yes

Basically just a solid rubber bush

Shape of the mount is slightly different so not sure fitting is as simple especially on the 986 but thats probably not as relevant on the rear engine cars

You can see on the underside they dont have the square section which helps locate or orient them correctly on the 986 - not seen the 996 setup yet



https://www.ebay.co.uk/itm/234268687380

They're the 964/993 RS mounts.

I'd say you got a good deal there ...

https://www.carnewal.com/products/964/p93114/RS-Mo...

[Adrian-9iafn]

What to measure and how do you see a 7mm drop ? Ive been looking on google, at pictures of very low mileage cars and non the wiser

My car looks like this, good or bad !?

[Slippydiff]

Discombobulate said:

Slippydiff said:

996 C2 at 60k miles.
After replacing with OE mounts, I experienced exactly what you describe.
Gamechanging.

You’re correct in saying the engine is a big, heavy pendulum, but I suspect the old mounts as they stretch and/or lose their damping qualities, and the engine then moves relative to the body at a harmonic frequency that wasn’t intended by the engineers.
The result is an unpleasant front to rear pitching motion that becomes more noticeable at speed over undulating, cresting roads.
The new mounts fixed the issue which I’d previously attributed to either dampers, or in extremis, a geometry issue.

As regards the tailpipes being a gauge of engine mount condition, when the new mounts were fitted, the tailpipes were less than 7mm higher, so in my experience the sag exhibited by the exhaust tailpipes is not an accurate indicator.

But they were lower.
If they were not 7mm lower than new then they probably didn't need changing. Not huge I agree, but measurable..

Ok, out of these images, in which image/s have the engine mounts been replaced, and in which image/s are the old mounts still installed ?

1.


2.


3.


Here are the tailpipe measurements before the engine mount swap :

Before N/S


Before O/S


And bear in mind that I stated "In my experience the sag exhibited by the exhaust tailpipes is not an accurate indicator"

[RiccardoG]

Slippydiff said:

Ok, out of these images, in which image/s have the engine mounts been replaced, and in which image/s are the old mounts still installed ?

I'd say images 1 and 2 = pre replacement.

[Slippydiff]

RiccardoG said:

I'd say images 1 and 2 = pre replacement.

Next. That's you BTW Discomark

[Adrian-9iafn]

I agree ! 1 and 2 pre replacement ?

[ATM]

Wait

I thought the back box on 996/997 was mounted to the car and has a flexi connecting it with the pipe coming from the engine?

Not like a 986 where the exhaust is all mounted to the engine assembly and moves around as one and in sync. Yes this one is sagging badly.

[Slippydiff]

ATM said:

Wait

I thought the back box on 996/997 was mounted to the car and has a flexi connecting it with the pipe coming from the engine?

Not like a 986 where the exhaust is all mounted to the engine assembly and moves around as one and in sync. Yes this one is sagging badly.

No, the the 996 cats are mounted to the rear engine crossmember (the end "tongue" of which can be seen arrowed in red in the image below) which in turn is attached to the engine mounts and they in turn are attached to the bodyshell)



The silencers are hung off two brackets which are bolted to the cam covers/cylinder heads, which are in turn connected to the rear engine crossmember, which is attached to the engine mounts, which are attached to the bodyshell ...

If those engine mounts sag (and rest assured if someone attached to 250kg of engine/transmission to your ankles and left that weight dangling from them for 22 years, day and night, you're legs might be past their best too ...) all the exhaust comes down with it it.