engine mounts
Hi all....just cruising through the last few days and notice a good number of references to motor mounts.....as in having to do them....is this considered a maintenance issue like TBelt/Wpump, or are they prone to failure and fixed on a as needed basis?....my 87 euro auto has 110kms. Is a motor mount failure catestrophic? and how do you know they need replacing.
John
John
HEy Jet, the motor mounts eventually wear out and will collapse. This causes the engine to sit low in the engine bay, and the mounts will actually be making metal to metal contact, causing vibration. It's no catastrophic failure kind of thing, just an annoying vibration.
To check the mounts, jack the car up, putting it on jackstands, then take a look at the "hooks" on the plates attached to the mounts. If there is a large gap between the hooks and their engagement points, like say the width of your little finger, then the mounts are shot.
As far a replacement goes, it's not hard, but is time consuming. I think John Pirtle has a step by step procedure on his web page. Not sure of the web address. You'll have to do a search on his name. Hope that helps.
To check the mounts, jack the car up, putting it on jackstands, then take a look at the "hooks" on the plates attached to the mounts. If there is a large gap between the hooks and their engagement points, like say the width of your little finger, then the mounts are shot.
As far a replacement goes, it's not hard, but is time consuming. I think John Pirtle has a step by step procedure on his web page. Not sure of the web address. You'll have to do a search on his name. Hope that helps.
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Perhaps an even easier way to check the condition of your motor mounts is to start your car, pop the hood, and rev the engine using the throttle linkage. If your motor "rocks" from side to side a little as you rev the engine, your motor mounts are probably OK. If your motor doesn't rock, your mounts are probably flat.
If you have flat mounts and replace them, use Ford truck mounts. I don't know the part #, but other Rennlisters probably will. They're much cheaper than Porsche mounts and fit just fine. New motor mounts will do more to improve the quality of your ride than anything I know. When I replaced mine, I thought I'd been given a new car.
If you have flat mounts and replace them, use Ford truck mounts. I don't know the part #, but other Rennlisters probably will. They're much cheaper than Porsche mounts and fit just fine. New motor mounts will do more to improve the quality of your ride than anything I know. When I replaced mine, I thought I'd been given a new car.
I've done it on an '87 and an '88, and in both cases, the easiest place to look for a clue are the air tubes. On both of those cars, the tubes easily passed under the engine bay cross brace. After new mounts, the tubes were a tight fit and pushed up against the brace. As pointed out, getting under the car and looking at the 'hook' is better, but I believe looking at the air tubes is reasonably reliable for a quick idea of their condition, especially if you're looking at a new purchase.
Originally Posted by bigs
Perhaps an even easier way to check the condition of your motor mounts is to start your car, pop the hood, and rev the engine using the throttle linkage. If your motor "rocks" from side to side a little as you rev the engine, your motor mounts are probably OK.
Thanks all....really appreciate the info. I will look up John Pirtles' site and see if i can find reference to motor mounts...don't think mine are particularly bad but am intrigued by Bigs comment about how new mounts made such a huge improvment in ride quality. If anyone knows the Ford truck part # for the correct mounts i would appreciate it.
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Has anybody tried the Jager Engineering "Shark Speed Mount?" It is basically a cheap & easy fix for worn motor mounts that they claim is 100% effective and does not damage the motor ('though I question that). It is simply a small piece of neoprene that is slipped between the bottom of the motor and the crossmember, transferring some weight to the crossmember and damping vibration through the neoprene at the same time. From an engineering perspective it is brilliant because it is simple and effective (the only two things that matter in engineering). The only thing I question is what kind of damage could be caused by carrying some weight of the motor on the oil pan (although that's how they store them when they sit at a wrecking yard waiting to be bought).
The Jager is a temporary fix at the most. Why bother, mounts are $50 for the pair and a days work under the shark.
Permanent fix for many years.
Best $50 I have spent on my cars.
Roger
Permanent fix for many years.
Best $50 I have spent on my cars.
Roger
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Does it have the "Do It Yourself" manual transmission, or the superior "Fully Equipped by Porsche" Automatic Transmission?
George Layton March 2014
928 Owners are ".....a secret sect of quietly assured Porsche pragmatists who in near anonymity appreciate the prodigious, easy going prowess of the 928."

Does it have the "Do It Yourself" manual transmission, or the superior "Fully Equipped by Porsche" Automatic Transmission?
George Layton March 2014928 Owners are ".....a secret sect of quietly assured Porsche pragmatists who in near anonymity appreciate the prodigious, easy going prowess of the 928."

I've gone the Jager route as a temprary expedient, and there was some improvement... however, when the weather got colder, the improvement went away until the engine was warm... I suspect the neoprene got stiff in the cold. I do intend to do the mounts the proper way this spring.
Originally Posted by Realist D.
The only thing I question is what kind of damage could be caused by carrying some weight of the motor on the oil pan (although that's how they store them when they sit at a wrecking yard waiting to be bought).


