u7t2p7

Is it a forgone conclusion that if your 16-19 year old 993 has the original engine mounts, that they should be refreshed (similar to the suspension)? How much does mileage play into the equation? Mine is a 97 C2S with 126k miles. Starting to feel a little notchy when cold from 1-2. I know that from reading numerous threads that the type of transmission oil can factor into this as well. Really just looking into the decision as to whether to swap the mounts.

Kika

MY belief is that there are too many variables that play into the condition of motor mounts, including age, environment (hot vs. cold), road conditions ( smooth vs. not smooth), hwy vs. city (how much stopping, and how quickly one decelerates), track driving. the more they are subject to being stressed, the shorter their life is likely to be.

In my experience, they last way longer then Mercedes Benz mounts, it seems like we had to replace the mounts on my wife's former 300CE every 2-3 years.

You can inspect the mounts, and if the oil has leaked out, then for sure they should be replaced. It seems like the bigger decision becomes OEM, RS, WEVO, or other...(none of which are really ad choices)

phoneyman

I don't think it is a 'forgone' conclusion, but they are consumable and that's a fair number of miles. I swapped mine when I got the car @ 128k mi. And they were definitely sagging. I was having notchy shifting also, so changed the mounts and tranny fluid. Neither fixed the notchiness unfortunately. But I think I'm a special case as those things have fixed many others people's issues in the past.

EMBPilot

i think it all plays in together.
i was actually getting a sticky shifter coming out of gear while braking hard. after updating the engine mounts with Wevo's and reenforcing the tranny sub support with Function First it totally resolved my issue.

fluid is prob also going to play into this. but checking these other items off your list couldnt hurt.

my transmission is a bit smoother while cold shifting 1 and 2 after switching from Delvac to Shell supplied by Sunset. aside from that, it feels the exact same as delvac did...

nine9six

I agree with Keith's list of variables that affect the life of motor mounts.

It could be that the MM have died long ago and in this instance, there may be no evidence of leaking...

I use the jack method of inspecting MM, by putting a floor jack under the motor case seam, and apply some lift whille observing the gap of muffler tips in relation to the bumper cover.

mpruden

+1 to this ^^^

My experience backs this up. Original mounts and 120,000 miles. No leaking, but a lot of sagging. The muffler tips moved significantly up toward the bumper cover when jacking up by the engine.

I also felt a slight improvement in shifting after replacing the worn mounts with genuine C4 mounts. It could be the placebo effect, though.

911F1

I put the RS mounts on my car at 100k+ miles. Ordered them from Sunset. Best price I found. The car feels more planted in corners and shifts are more direct. A little more vibration at idle. I don't mind the vibration though. Kinda like it.

earossi

The reality is that all the elastomers in your car are probably past their life spans. So, suspension bushings and motor mounts are all suspect at this age. Catastrophic failures of motor mounts, such as the loss of fluid are easy to spot; but, even if the fluid is still captured, the elastomers in the mount are probably failing.

There are several engine mounts available. A lot of folks have gone with WEVO mounts. I chose the economic route to move to the RS mount. As pointed out above, great pricing exists on these mounts from Sunset. Unfortunately, I changed out my transmission at the same time I did the engine mounts, so I don't know which changed my shifting......but, my gearbox is much more precise now than in the past. Feels as good as the gearbox in our BMW 330....which has always been the gold standard for me.

Mike J

I have seen a LOT of worn out motor mounts - but only a few that were leaking. I use the usual test, but I put the car on the lift and then lift the engine and see what happens.

The other mounts to watch out for are the subframe mounts - you can test them with a large bar against the pinch weld and the mount - they will move a bit, but excessive movement means they should also be replaced.

I have a low sample pattern that Turbos consume their motor mounts and subframe mounts at a faster rate than the NA cars, which does makes sense given the difference in torque and HP, and they use the same mount. This conclusion is not statistically significant though...

I would say that after 100,000 miles its pretty well certain the mounts are either shot or well along the way. . The same goes for the front A-arm bushings, and all the rubber bushings should be inspected periodically anyways.

Cheers,

Mike

NC TRACKRAT

Our '95's original mounts failed after only 14,000 easy miles. nine9six's method was the tell-tale sign.

Jay J

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