How do I determine the condition of my engine mounts.

[DCinVA]

I suspect my engine mounts need to be replaced. How can I tell if they are worn. I recall reading somewhere that if the big metal washer thingy was making contact with the other metal part of the mount, then they were bad. Well I dont think mine are making metal to metal contact, but it looks to be pretty close to being metal to metal contact. Is there some test, or measurement, to determine that they are bad?

I did do a search, and read results for a hour, could not find what I needed.

Thanks in advance.

1986 Carrerra
232k miles (engine runs strong, transmission pretty clunky)

[ChkbookMechanic]

You should be able to see the rubber in the motor mounts. If it is cracking or feels brittle, you could need new ones.

[robert walsh]

From a visual aspect the cracking etc. would be visible. If you start the car and leave it neutral and have someone rev it up while you watch for movement related to the mounts, then have them put it in 1st while applying the brake slow let the cltch out and again watch for lifting of the engine, by far the sure fire way is to replace all four, engine and trans, mounts with sport mounts for less than $120.00 and less than an hour of your time, very simple job.

[RWebb]

probe it with a screwdriver to ensure elasticity

rock the whole powertrain back and forth to see how far the excurision is and how quickly it damps out

pay attention to the feel over RR tracks & bumps

[RWebb]

PS - cracks may not be evident since the thing is under compression while in the mounts

[DCinVA]

Thanks everyone. I will have a good look at them tonight, and I will try to take a few pics. I feel pretty confident that they are toast, and for $120 it is probably best to replace them. One thing I have noticed recently is that when I release (engage) the clutch, I get a sense that the engine is moving more than it should, but I really have nothing to compare it to.

[azasadny]

When I dropped my engine a few years ago, my motor mounts crumbled and fell apart and I replaced them. I didn't see any obvious signs that they were bad, but the engine bounced a little on acceleration and after replacing the mounts, the shifting was much smoother.

[robert walsh]

Replace all four and it will keep your entire driveline (eng/trans) in it's palce. My transmission was seemingly lifting durring hard acceleration, the mounts fixed that issue, i did the engine mounts at the same time because they are inexpensive and easy to replace.

[RWebb]

I might have some extras - used but in decent cond. Let me know if you need a set and I'll go thru the pile of stuff for slae and see if they are still there.

[DCinVA]

Here are a couple of shots of the existing mounts.

This pic is passenger side. There is not a lot of rubber between the engine mount base and the big washer on top, but the rubber is still plyable, and not cracked badly.


This pic is drivers side with the car jacked up by the engine base. The rear wheels are barely off the ground, but the entire weight of the car is pushing on the engine mounts. The deflection is about a half inch. The rubber on this
side is plyable as well.



So the rubber appears to be in reasonable condition. It is flexible, its not cracked and turned to dust. The question is this, Is 1/2 inch of deflection OK, for these engine mounts? I am inclined to think that they are OK.

[Peter Zimmermann]

By your pictures and description, your mounts are JUNK!!!

Pic #1: The rubber should not bulge out around the outside of the washer - your washer is actually cutting into the rubber.

Pic #2: There should be almost no deflection when lifting the engine with a jack - are your lower mount washers missing???

If you have a copy of my book, page 91 has a picture of how a mount in good condition should look...

[peppy]

I remember reading somewhere that you start to lift the back of the car with a floor jack under the engine. As you do this watch the engine movement in relation to the car lifting. You do not need to lift the car just put pressure on it.

[dshepp806]

All new,..period...


Best,

Doyle

[DCinVA]

Pictures tell the real story. Thanks everyone!
Pete. I do have your book, and I do see the difference between your pic pic on page 91, and my old mounts. I am ordering a new set tomorrow.
What are the pros and cons of using the standard vs sport mounts.

[slodave]

Sport mounts should allow more engine/tranny noise to transfer to the body and you may feel it. I used the Wevo mounts when I changed mine out a couple of years ago.

[robert walsh]

Sport mounts are what were anre used on the cabriolets and now recommended on all 911SC's because there rubber core is firmer than standard, they are exact same size etc. (do all 4 eng/trams). These are "NOT" the all metal racing mounts which pass along way too much vibration for road use.

[john70t]

+1. Sport mounts (and new coupler bushings) made a huge difference in how the car shifted.
No more gearshift lever rolling around, and the engine feedback makes shifting easier as well.

Use lube and heat when removing the cross bars, in early cars they have been known to break.

[DCinVA]

I am going to order 4 new sport mounts today.

[DCinVA]

I installed my new sport mounts a couple weeks ago. What a difference this made. It changed the whole feel of the car.

Thanks for all of your advice.