Cobb RMM problem

[Sil3nt611]

I installed my Cobb rear motor mount on Saturday. Left my parent's place on Sunday to go back home having not driven the car with the mount yet. There is a weird vibration when I turn on the car, but it seemed fine once it was going. After I awhile I started hearing a vibration noise when on certain pavement. I made sure it wasn't something inside the car. I looked under the car when I stopped for gas and all the bolts I could see looked to be on there just fine. I tightened everything down with an air impact gun. Is this normal for the Cobb motor mount or is something loose? I would have jacked it back up to investigate, but I didn't have time last night since my jack and stuff is at my uncles and I can't get over there until this evening to check.

 

[alf45]

Have you try Turning the heather to off just to make sure it is not the vibration from the a/c

 

[frankiefiesta]

Aftermarket mounts will have increased vibrations. If it's new give it a couple weeks to break in.

 

[Zormecteon]

When I had the mountune RMM done, it came with torque specs. Did the COBB one? .. using and air impact gun is NOT the same thing..... and as said above, you'll have more with the AC running, and for a while until it breaks in.

 

[Sil3nt611]

I'll check the bolts and nuts tonight then. Something must be loose.

I did turn off the HVAC system at one point and it was still making noise like something was loose. I know there will be more vibrations, but aside from the vibration noise on startup there's really none to be said of. I know what vibrations are, in stock form and at idle my ZX2 was a vibration machine. You could watch the steering wheel vibrate a good couple centimeters. Anything less than that in vibrations is pretty negligible to me. This is just a noise that sounds more like something is loose.

 

[me32]

Possible not fully tq to proper specs

 

[Sil3nt611]

I found the torque specs are 50 ft/lbs. I needed a good reason to buy a torque wrench anyway.

 

[JasonHaven]

There will be a moderate increase in NVH until it breaks in. I got mine installed a month or so ago and have noticed it's getting a bit tamer in terms of vibrations.

 

[koozy]

did you install the washer?

 

[Sil3nt611]

Yes I installed the washer. It was a loose bolt at the bushing part of the mount. Torqued it to 50 ft/lbs as well as the other bolt and tightened down the other nuts a bit more to be safe and it is much better. No more weird vibration noise on startup. Now that it's properly tight I do get a tiny bit of vibration at idle, but it's nothing I'm worried about at all because that was expected. Considering the vibrations I got on my stock mounts on my ZX2 (that were new), I was on paradise with the lack of actual vibration at idle with the Fiesta stock mounts. With the tiny vibrations at idle now I barely notice it. If you're at all sensitive to the vibrations this mount puts out at idle when properly torqued, sell your Fiesta and go get a luxury car...