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Discussion Starter · #1 ·
got PADM fail warning light few days ago.'
it says okay to drive but im thinking about what would happen if I do not change the mount and still drive as usual(aggressively)? would it cause any further damage to the car or I just give up the option to stiffern the drive train?
 

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I drove approx 1500 km with a padm failure on 1 left mount, not completely without limits. Just try it out. I wouldn’t risk damaging more than only the transmission mount (PDK itself is quite expensive), would you? I was wondering if I changed them with fixed mounts, howmuch comfort I would loose. At the end I swapped the left mount for a new dynamic mount.


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Discussion Starter · #3 ·
I drove approx 1500 km with a padm failure on 1 left mount, not completely without limits. Just try it out. I wouldn’t risk damaging more than only the transmission mount (PDK itself is quite expensive), would you? I was wondering if I changed them with fixed mounts, howmuch comfort I would loose. At the end I swapped the left mount for a new dynamic mount.


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i wouldnt want to risk as well, but I've heard about this PADM fail is just failure on the coil thing, not the mount itself. which means it is still physically "mounting" but just no longer have the option to stiffen up and only stays in soft mode. the car is no longer under the warranty anymore since its 2014, trying to find out the way to save money but not making it worse for sure.
 

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I drove mine normally for over a year after failure without issue. As stated the mount still works, its just no longer adaptive and will not firm up in response to the G force changes on the car or the sport mode changes, so essentially in standard mode all the time now. You likely wont even notice the difference driving it other than the fault that will appear at every start.
 

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Discussion Starter · #6 ·
I drove mine normally for over a year after failure without issue. As stated the mount still works, its just no longer adaptive and will not firm up in response to the G force changes on the car or the sport mode changes, so essentially in standard mode all the time now. You likely wont even notice the difference driving it other than the fault that will appear at every start.
that makes sense
 

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Resurrecting old thread. I’ve had my ‘15 981C for a month now and when I was going through the Carfax originally for the purchase I remember hesitating about one thing and one thing only… the fact that “transmission mounts” were replaced just over three years into service exactly four years ago.

I was on my way to the barber shop today driving spiritedly and in a right to left flowing chicane the PADM failure triggered on the dash. After reading up it sounds like a lot of cars with PADM from the mid-teens have this issue. Usually it’s the left mount to go first. Sure enough after running diagnostics I had a “left drivetrain mount pressure sensor, short circuit to ground in signal line” error message.

What I’m wondering is could there be damage to one of the wires external to the mount or does this sound like something internal to the dynamic engine mount itself? I guess this is just a remove and replace with new type of deal. Other question is I noticed the latest part number is updated-were there revisions to the original units to make the design better? And what the hell made these things so reliably faulty to begin with? Frustrated Porsche didn’t issue a TSB or something with these dynamic mounts that had a far less than intended lifespan.
 

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Resurrecting old thread. I’ve had my ‘15 981C for a month now and when I was going through the Carfax originally for the purchase I remember hesitating about one thing and one thing only… the fact that “transmission mounts” were replaced just over three years into service exactly four years ago.

I was on my way to the barber shop today driving spiritedly and in a right to left flowing chicane the PADM failure triggered on the dash. After reading up it sounds like a lot of cars with PADM from the mid-teens have this issue. Usually it’s the left mount to go first. Sure enough after running diagnostics I had a “left drivetrain mount pressure sensor, short circuit to ground in signal line” error message.

What I’m wondering is could there be damage to one of the wires external to the mount or does this sound like something internal to the dynamic engine mount itself? I guess this is just a remove and replace with new type of deal. Other question is I noticed the latest part number is updated-were there revisions to the original units to make the design better? And what the hell made these things so reliably faulty to begin with? Frustrated Porsche didn’t issue a TSB or something with these dynamic mounts that had a far less than intended lifespan.
They did do as TSB for the 911 models which use essentially the same mounts with different length connection bolts on them. The 911 uses them as motor mounts since their engines are flipped around 180° from ours. They created a rubber cover for their mounts, some of which were failing within a week on a new car, but nothing for the 981 models that I am aware of. I have no idea if they have changed something on the newer models though?

This makes me wonder if its just a water issue as mine failed like many others, and its always the same error people get when checking codes of " signal line shorted to ground" so its an electrical failure. They are exposed under the car with a square electrical plug snapped into the top of them, so it is possible for water to be splashed up there, but all except the plug is completely sealed. I would at least place some dielectric grease on the plug when replacing to waterproof the connectors, and probably not a bad idea to do proactively anyway

Mine was $1,700 to replace, and the part alone is $1,300 of that, even if you DIY. They are the parts circled in red on the below image
 

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This is infuriating. Porsche has to be aware that there is some inherent design/manufacturing flaw to these parts or the conditions and environment they are subjected to and chose not to reconsider. Read about brand new 718s on the 718 forum from 20/21 model years with PADM failures within the first 5k miles. They're all luckily covered with warranties but mine was out of Porsche certified warranty as of 8 months ago. No how-to videos other than a 911 on youtube but it sounds like it would be a relatively straightforward swap.

ICNU, thanks for the dielectric grease idea that's certainly worth doing. Car is going into Porsche for my side axle carrier recall and they said they'll check it our for me. I'll just wait to get some feedback and then tackle it myself. I literally bought this car to work on it and challenge myself. Bring it!!
 

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Yes, these PADM mounts have a history of spontaneous failures for more than 10 years since they were first introduced. Sad to hear its still happening, even on the current 718 models. Ive considered swapping them out for the standard mounts if another one of mine fails, considering they are only about $500 a pair.

I would have to live with the warning at every startup though, or see how much the dealer would rip me off to code them out with a PIWIS, if I could even get them to do it for me. It would still be cheaper than replacing them at $1,300 each over and over again, as several guys who had one fail had the other fail as well later on.

My suggestion is to buy the replacements from FCP Euro since they have a lifetime credit swap for everything, even consumables like oil, brakes, etc. You buy the new part, and they will credit you back when you send the old one in. My Indi however would not allow me to provide the part, as they claim they will only warranty their work if they provide the parts.

Its been 2 years and about 10K miles since my first one failed, however my car has not been driven in the rain since that time either since its just a weekend toy, assuming its water that causes these failures. The fact that their solution on the 911 was to add a water tight rubber boot over the connection seems to indicate to me that Porsche knows this is the problem
 

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Yeah I got my car back Friday after they did the left mount and -surprise!- Monday I had the PADM failure message back on the dash. After running diagnostics it’s the right one this time. I should have followed my instincts and just told them to do both at the same time. eyeroll

I’m concerned on the rain portion as well since this is my DD but hey… I’ve got this repair warrantied for 2 years now. So fingers crossed the next time they fail it’s within the next two years!
 

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Do you have any information on this? I'd like to poke around and find a solution if possible.
I was able to dig up the TSB on the 911 PADM mount issue, and it's water just as we suspected! I'm not sure why they did not issue this new rubber cover solution for the 981 or 718 models?

I have a new idea I'm doing to try. It's time for my annual service, so I'm going to see if I can spray both of my electric plugs for the mounts with plasti dip spray which essentially a peelable rubber coating while its up on my lift.

There really isnt anything above them other than the floor pan, so there shouldn't be any complications for overspray on the surrounding area as the stuff will peel just peel off, and if it works, there should never be any future need to be working on anything in that particular area for the life of the car anyway.

It should also be possible for me to stuff some rags around the mount to keep the spray contained more to the plug connection itself as well. It seems this "should" help to prevent water ingress if driving in wet conditions.
 

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I was able to dig up the TSB on the 911 PADM mount issue, and it's water just as we suspected! I'm not sure why they did not issue this new rubber cover solution for the 981 or 718 models?

I have a new idea I'm doing to try. It's time for my annual service, so I'm going to see if I can spray both of my electric plugs for the mounts with plasti dip spray which essentially a peelable rubber coating while its up on my lift.

There really isnt anything above them other than the floor pan, so there shouldn't be any complications for overspray on the surrounding area as the stuff will peel just peel off, and if it works, there should never be any future need to be working on anything in that particular area for the life of the car anyway.

It should also be possible for me to stuff some rags around the mount to keep the spray contained more to the plug connection itself as well. It seems this "should" help to prevent water ingress if driving in wet conditions.
What an idiotic solution...
 

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I was able to dig up the TSB on the 911 PADM mount issue, and it's water just as we suspected! I'm not sure why they did not issue this new rubber cover solution for the 981 or 718 models?
Looking at this TSB it's clear the mounts are a very different design to the tx mounts in the 981/718. I can only find a workshop campaign for the 992.

Below is video I found of a bloke changing the PADM mounts in a 991. The mounts here look pretty much identical to those in the 981/718. It's hard to know where the water is getting in. Whether it's getting in at the plug, top cap or underneath I don't know.

When I had the project car up on the lift the other day looking at the mounts I didn't see a solution other than wrapping the mount entirely, which I think would be very difficult.

It does say in the TSB that the effect of the failure is for it to revert to a normal mount, so replacement for driveability isn't required unless you specifically want the stiffening of the mounts.

Coding out looked simple in PIWIS development mode. Go to the PASM control unit and in manual coding without MCR rules you just select the option that is applicable that would remove the PADM but still include PASM and lowering options fitted to your car.

 

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Yes, the 991 PADM engine mounts look almost identical in a parts diagram to the 981 tranny versions we have other than maybe a little longer threaded stud if I recall correctly. They look completely sealed like a can when looking at them on my car, but I guess there is a possibility of water entry where the bottom stud exits the studded mount to the car, and there seems to be holes in the top portion that cannot be seen in the car as they are up against the floor pan, and this is where the 992 design rubber cover goes.

Why the holes are there in the first place is mystery to me if that is the entry point? Its not possible to see this in detail without them in your hand out of the car, but the attached link gives some detail in the images


This failure has been around for many years, long before the 992 where they appear to have changed the design. I guess the new 992 design still isn't working otherwise there wouldn't be this TSB to add this rubber cover, so its seems its just another multi year/model issue that they cant seem to get a handle on. This PADM mount issue has been happening since they were first released almost a decade ago just like the door panel warping issue.

Its good to know they can be coded out, so thanks for that info. Plan B for me if another one fails is to replace them both with the standard mounts which are far cheaper parts, but I wasn't sure if I would get stuck with the startup dash warning every time if they couldn't be coded out without taking the rest of the Sport Chrono functionality with it
 

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Its good to know they can be coded out, so thanks for that info. Plan B for me if another one fails is to replace them both with the standard mounts which are far cheaper parts, but I wasn't sure if I would get stuck with the startup dash warning every time if they couldn't be coded out without taking the rest of the Sport Chrono functionality with it
I can't be sure but it looked like a bit of a no brainer and it didn't seem to have anything else to do with other Sport Plus items. The options available were all the different combinations of PADM (yes/no), PASM(yes/no) and and suspension lowering level (0, -10, -20). Until you went and did the coding you couldn't be 100% sure of the result

I look at that image from ecstuning and think the only way to possibly seal it well is to remove the mount entirely and spray with some sort of rubber waterproofing material like the underside of the car. You probably wouldn't spray the underside where the shaft comes out as this is the flexible rubber bit that allows the movement.
 
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