How much flex is normal for the passenger side motor mount?

[Bosnian Fiesta]

Car is a 2014 with 40k miles. Daily driver, bought new - no track or race use.

Been dealing with clunks and sloppy shifting since early on. Cobb RMM and Boomba shifter bushings helped some, but didn't eliminate the problem. Recently I pulled the passenger side motor mount to inspect.

Holy hell this thing has a lot of play. Very similar to what you see in the video: https://youtu.be/vk5L3d2F0hQ?t=1m4s

For guys who have pulled the mount, is this normal? No evidence of oil leaks or internal separation, but I'd be shocked this is functioning as designed. It would allow a huge amount of engine movement.

Switching to solid mounts is out of the question for a daily, so I'll use the Powerflex insert to stiffen the OEM mount, but before I do that I want to check if that flex in the old mount is normal or if I should get a new mount?

I appreciate any advice.

 

[koozy]

It's normal unless the center bolt is broken or the fluid has leaked out. Adding the powerflex insert alone will squash a lot of the movement, even on a worn out mount. The passenger side mount is fluid filled with 0W oil, so it won't be solid and will have a lot of play. You can see the plastic baffles in the photo below that the oil flows through.

I've dissected mine and filled it with 80A eurathane; and later paired it with a Black Powerflex insert. The driver side is not fluid filled, but just as soft, I also filled that with 80A before an insert was available from Powerflex. If you're going to get the insert for the passenger side I'd recommend upgrading the center bolt while you have it out. Bolt and insert are available from Whoosh [MENTION=5976]ron@whoosh[/MENTION].

The ARP bolt has a shank and not threaded all the way to the head where most of the breaks have been occurring at. Don't use an impact gun on the centerbolt if you do. You'll need a skinny wrench to grab hold of the center post the center bolt screws into, a 1/2" breaker bar and some gusto to break loose the center bolt because it's held on with red loctite. https://whooshmotorsports.com/colle...r-engine-mount-bolt-upgrade-kit-free-shipping

 

[jeff]

Car is a 2014 with 40k miles. Daily driver, bought new - no track or race use.

Been dealing with clunks and sloppy shifting since early on. Cobb RMM and Boomba shifter bushings helped some, but didn't eliminate the problem. Recently I pulled the passenger side motor mount to inspect.

Holy hell this thing has a lot of play. Very similar to what you see in the video: https://youtu.be/vk5L3d2F0hQ?t=1m4s

For guys who have pulled the mount, is this normal? No evidence of oil leaks or internal separation, but I'd be shocked this is functioning as designed. It would allow a huge amount of engine movement.

Switching to solid mounts is out of the question for a daily, so I'll use the Powerflex insert to stiffen the OEM mount, but before I do that I want to check if that flex in the old mount is normal or if I should get a new mount?

I appreciate any advice.

Yeah yours is toast. I removed mine a few weeks ago and it was solid, like new. I think you need a new mount. Check the insert thread (search for "inserts" iirc), I just posted a detailed install/review/etc. there a few weeks ago for both side mount inserts, I love them.

 

[Bosnian Fiesta]

Actual video of mine: https://streamable.com/8ui0p

A replacement was cheap enough so I snagged one at the local dealer. Looks identical, but significantly stiffer. I could barely get any flex out of it. I installed it along with the PF inserts and will write a review when I get the car buttoned up.

 

[koozy]

can you tell if the new one is still fluid filled? I wonder the part has been superseded with an improved version. You can tell by looking at the bottom of the mount.

 

[Bosnian Fiesta]

It's still fluid-filled. The new mount was recently manufactured (01/2018), but P/N & design are otherwise identical.

It looks like the hydraulic cylinder part of the mount is a carryover from the base Fiesta. Only the aluminum bracket that attaches it to the block is unique to the ST. Kind of a surprising decision given that the ST's torque output is double.

It looks ideally designed for the base trim, too. The hydraulic element reduces NVH in idle to improve refinement of the dated Sigma engine design and the rubber element allows for significant fore/aft flex to absorb the notoriously hard shifts of the PowerShift dual clutch transmission. Clever solution.

That second part also makes it crap for the ST. I'm sure under hard launches the motor moves back and forth like crazy, even though the mount isn't actually broken. If that's true than the upgraded RMMs are actually just a band-aid fix for the real problem, which is the hydraulic upper mount.

Could also be talking outta my ass though. I'll know more when I get the car back on the road.

 

[koozy]

Good reason why some break the center bolt once the rubber in the mount has fatigued, increasing the amount of stress on to the bolt.


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[Bosnian Fiesta]

Quick update: new OEM mount + PowerFlex insert + Motul DCTF fill have significantly improved shifting performance.

Shift clunk is gone, gear selection is now smooth and effortless. NVH increase in idle is negligible but vibrations between 1200 - 3000 RPM are more pronounced. Totally manageable though. The car has a bassy resonance to it now, it's kinda neat. Should settle down as the mount breaks in.

 

[koozy]

Quick update: new OEM mount + PowerFlex insert + Motul DCTF fill have significantly improved shifting performance.

Shift clunk is gone, gear selection is now smooth and effortless. NVH increase in idle is negligible but vibrations between 1200 - 3000 RPM are more pronounced. Totally manageable though. The car has a bassy resonance to it now, it's kinda neat. Should settle down as the mount breaks in.

you need to update us on your fuel pump issue thread if your car is running good now.

 

[Bosnian Fiesta]

Done deal - ended up being a bad HPFP.