I installed the power flex bushing kit about 7yrs/30k miles ago on my ‘05 r53… when I was accelerating from a stoplight earlier this week, I heard a loud/weird sound. Almost like a tire was rubbing the fender - to be fair, the ac and music were blasting, ha. I immediately pulled over and cut the car off. When I restarted the engine, no noise but when the fan kicked on for the ac it happened again. I was about 1/2mile from the house so I limped home. Looking over everything, I saw the clean yellow bushing through the passenger wheel well. Hind sight being 20/20, it turns out the entire engine had shifted forward just enough for something to hit the fan. I attached a couple pictures below.

Yes, I know everything is covered in oil. I’ve had a valve cover leak, oil filter housing and cooler leak for a while. I replaced those gaskets and used 3 or 4 bottles of break clean and degreaser while I waited for a new lower mount to get shipped. Everything is back together and good as new!

 

Wow - That's odd.
Urethane is generally impervious to solvents (with the exception of toluene if not mixed/cured properly)...
I've NEVER seen urethane swell or "break down" like that before.

 

YOWZA!

that is a catastrophic failure!

i remember when i ran that version i thought it was overly vibratory, but i did not remove the black insert which would've made it more compliant because i had concerns about the empty voids making it structurally unsound & by the looks of yours it appears as a collapse because those voids perhaps?

were you running it without the insert?

that 95A insert durometer black formula is super stiff,
the yellow is 70A which is considered soft cruiser style with skateboards




i changed over to the fancy badboy they make, 80A purple/70A yellow
& i love it much

 

Wow so i wasnt the only one!

Funny story.... Mine failed within 300km, only being 3 months old. Purchase was still fresh so I contacted Powerflex, I asked them if I can pay the difference and get the full mount. I ended up talking to poweflex UK, who referred me to US. Somewhere during that transition somebody missed something and the full mount showed up at my door.

can confirm i was running the black insert when it failed. It did vibrate like mad, more then the full mount.

 

thanks for the pics & description

much appreciated!

it always brightens my day & warms my heart when we are actively engaging here on the forum with high-quality helpful postings which expand the first-hand experience account of knowledge base with supercool added bonus of visual documentation.

NAM is the numero uno archive.

interesting that it appears to be the same failure pattern, like a shear, in the very same stress spot.

wonder if they had a bad batch? Or is this an inherent design flaw due to material/construction choice?

 

^^^Agree^^^
Thanks for the pics.
It does make me wonder why the failure/ split in the same location?
Does Powerflex still sell that style of inserts?

I opted for the Yellow Powerflex inserts. Leaving the large end of the bone with the OE black rubber, sandwiched between Powerflex yellow inserts. The small end of the bone was gutted and replaced with Powerflex purple insert.




It's been more than10k so far and all seems well.

 

@Here2Go I have a feeling yours will last. Them voids have to be the cause of failure on our design.

They do still in fact sell the failing one, PFF5-120.
I purchased the Gen 1 handling pack PF5K-1004 which that bushing is part of also.

@JRoze Powerflex has a lifetime warranty providing you are the original purchaser with proof. They were great when i dealt with them, ask them if you can pay the difference for the full mount. Worked well in my favor!

 

I searched NAM and a few of the other forums and didn’t find any other failures- so weird that it did fail. More so that someone else had the same exact problem I did! It was so crazy I had to post it.

I purchased a URO branded mount to get back in the road as this is my daily driver.

I completely forgot about the warranty. I was the original buyer but idk if I’ll be able to find the proof… worth a shot! Thanks!!!!

 

Dig through your email, benefit with purchasing most things online these days, cant imagine hanging onto every piece of flimsy paper.

Dug deeper myself and found all the failure pics, not only did mine fail at one of the openings, but also the up and down offset portion to boot.... almost self explanatory

 

Wow. Interesting. I used to run those bushings in my lower mount, but I had a time where I was stuck in stop-and-go traffic on a big long hill in ~100 deg heat. It honestly felt like I had a broken mount, though it was fine when I removed it. My guess is that it was getting soft in the heat, but I never tried to prove that was the case. I swapped to a Vibra-Technics rubber mount not too long afterwards.

 

IMO -That's a pretty fair assumption @deepgrey .
Although in all my years casting polyurethane in various shores and durometer (non automotive), I'd never subjected them to temps beyond 30°- 75°/room temp.

Kinda wish I was still in that role with access to a full (SXF) shop to test some of the products (e.g: Smooth-On) we used.
But agree - I suspect your theory has merit.

BTW: Are you "running" Vibra-Technics both upper and lower mounts?
If so - How's the level of vibration?
I'm running the Vibra top mount but also considering changing out the lower with Vibra at some point....just for durability/longevity sake.

 

Yes, upper and lower Vibra-Technics mounts. The street density ones, or whatever they call the softer durometer (I might be thinking of 034 Motorsport terms). The trans mount is the original with Powerflex inserts. I have quite a bit of vibration at idle, though I think I currently have more than usual because the car sat for a while. I probably need to run a couple of bottles of Techron through it. I had a pretty bad hunting idle for a little while that improved after driving it some.

I think at the time I searched around the web and ran across some guys with Camaros or Mustangs or something - I forget what exactly - who had issues with poly engine mounts getting hot. It’s nice to have someone else think it’s plausible. It was sitting there baking next to the oil pan over asphalt in the afternoon sun. It must have been well above ambient temps right there.

 

I'm still running the OE lower mount with Powerflex inserts at both ends. It's gonna get hot out here in the desert this summer. I'll definitely pay attention to any changes in vibration with the possibility of the urethane softening.

BTW: I will never forget working a gig outdoors in Atlanta - October 3rd 2018 or 2019 - temperatures soared to a record 110° without a cloud in the sky.

 

I’ll be curious to see if you notice anything. I don’t know that it would have stood out if I wasn’t on that hill (Northside southbound below the railroad bridge south of 75). And there’s also of course the possibility that I just wasn’t driving that great that day, but I really did think I had a failing lower mount.

That gig sounds rough. I hope it was at least reasonable humidity and that you had a nice big hat.

 

Atlanta traffic = ugh!
'used to love being on a hill in a manual with the guy behind you cozing up inches from your rear bumper [sarcasm].

On that last note - I'm pretty happy with the setup/combo I currently have right now (Vibra upper & Poly inserts lower). Now that both mounts are pretty much "broken - in"; vibration inside the cabin is pretty moderate/tolerable.
What I find really impressive, is that when standing outside next to the car, you can't even tell that it's running.

(Yeah - To say that gig was brutal is an understatement. No hat for me (messes up my pompadour )...
Paid crazy money...But never again.)