odd vibration at 2500 rpms'ish

DubC

DubC

Greenie N00B Member
Greenie Member
quick background:

installed Damond passenger side mount and trans mount. already had a stage 2 cpe rmm. did a few other bolt-on mods (downpipe and tmic). i'm now hopefully finishing up some tuning with Hypnotic.

this was all done 473 miles ago.

have been noticing in the last few days that there is this odd vibration around 2,500 rpms no matter what gear i'm in. 6th gear is much less noticable. the vibration stops if i press in the clutch and the rpms drop. it goes back to normal. anything above that and it pretty much goes away as well.

i thought it was some tire issue as my tires are getting low treadlife and i'm about to replace them. they do drone around 70 mph, but this isn't that.

so i retorqued the motor mount bolts (was about time to do it anyways). the passenger side might have needed it a tiny bit. the trans mount bolts, however, were still solid at 40 ft lbs. i couldn't do the main bolt (70 ft lbs) since it's blocked by the plate.

Anyone have any idears or other things to check before i drive it again? shifting seems fine and i don't hear anything. i feel that vibration thought hot and heavy in the seat. i know that these mounts can add quite a bit of vibration but this wasn't there initially.
 
so might have found a post about this on .... the other forum. if you google 'mazdaspeed3 transmission vibration' it's the first hit. i don't wanna link it cuz i'm not sure i supposed to. but the gist of it is, according to one feller:

"Just so you guys know, it's a harmonic issue with the dual mass flywheel. It's nothing to worry about other than being annoying.
I've seen this on multiple applications already. It's always there, it's just exaggerated by the stiffer mounts. Some DMFs will be worse than others when it comes to this it seems.
Edit: You know this is the case if you push the throttle (or clutch pedal) and it goes away."

so...maybe this.
 
On a stock clutch it is normal, same way with some timing chain noise from the PMM. Yes, we have a noisy clutch and as long as the noise and vibes go away when you step on the clutch, it should be fine. IIRC the noise we get from our engine typically happens between 2500-3200 rpms.

The mounts will break in and the NVH will reduce. On DM mounts, I think mine settled in 300 miles, compared to the old JBR's that took like 3k to fully settle.
 
Yeah it goes away when I engage the clutch. Maybe it was more pronounced since I was in rush hour and in that range longer coasting.

Glad to hear it’s nothing out of the ordinary. With all my changes at once I hear and feel all kinds of new things and it’s hard to tell what’s fine and what’s not.


Sent from my iPhone using Tapatalk
 
Hi I have similar vibrations happening and I have Damond trilogy. I first noticed it after the rmm install and it's never settled since. It only happens under certain circumstances however, like during aggressive driving and the shift hangs right at 3k, during some deceleration at 3k, and other unmemorable reasons. My throw out bearing also sucks which I imagine makes it worse. Just here to confirm your issue [emoji2371]

It is also resolved when I push the clutch in and rpm's drop below the problem area, usually 2600ish

Sent from my meat puppet's electric box
 
deeAYEennENNwhy said:
Hi I have similar vibrations happening and I have Damond trilogy. I first noticed it after the rmm install and it's never settled since. It only happens under certain circumstances however, like during aggressive driving and the shift hangs right at 3k, during some deceleration at 3k, and other unmemorable reasons. My throw out bearing also sucks which I imagine makes it worse. Just here to confirm your issue [emoji2371]

It is also resolved when I push the clutch in and rpm's drop below the problem area, usually 2600ish

Sent from my meat puppet's electric box
Click to expand...
This is normal with mounts. I had them with dammond, although not as bad, and my jbr 88duro trilogy. Just put a dildo in the seat and enjoy.
 
Last edited:
DubC said:
Yeah it goes away when I engage the clutch. Maybe it was more pronounced since I was in rush hour and in that range longer coasting.

Glad to hear it’s nothing out of the ordinary. With all my changes at once I hear and feel all kinds of new things and it’s hard to tell what’s fine and what’s not.


Sent from my iPhone using Tapatalk
Click to expand...
 
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