Enormous Vibration at 1000-1300 RPM
12-27-2019, 05:17 PM
#1
Registered
Thread Starter
Join Date: Dec 2019
Posts: 15
Likes: 0
Received 0 Likes
on
0 Posts
Enormous Vibration at 1000-1300 RPM
Hi guys, I have 07 RX8 auto, it jas 115000 miles. I had an issue, where the car would vibrate at the stop when I'm in gear. I replaced spark plugs and wires, didn't replace coils yet, I'm saving for the BHR ones. Car also has BHR Midpipe with no cat. So to fix the issue of vibration on the redlight I decided to replace the motor mounts and replaced them with the RX8Performance ones. The car now doesn't vibrate when I'm stopped at all, but when I start to accelerate, it vibrates enormously bad between 1000 and 1300 rmp and vibration dissapears above 1300 and below 1000. Vibration is so bad that the whole interior is shaking. I don't know what to do now. By the way, the original mounts I replaced were not broken. Should I keep the new mounts and replace coils or should I put the old mounts back? I know many people have issue with vibration at the stop but I couldn't find anyone with problem like mine. Thank you!
12-27-2019, 06:35 PM
#5
Registered
Thread Starter
Join Date: Dec 2019
Posts: 15
Likes: 0
Received 0 Likes
on
0 Posts
Well, my concern is that it fixed vibration at idle but now there is vibration at 1000-1300 RPM, I'm wondering if it is due to new mounts or what caused it. Maybe the new mounts have to be broken in and it will dissapear with time.
12-27-2019, 06:42 PM
#8
Registered
Thread Starter
Join Date: Dec 2019
Posts: 15
Likes: 0
Received 0 Likes
on
0 Posts
12-27-2019, 06:47 PM
#9
Registered
Thread Starter
Join Date: Dec 2019
Posts: 15
Likes: 0
Received 0 Likes
on
0 Posts
Yes, I can feel they are more stiff than the factory ones, but this vibration at those rpms is really bad and loud. I actually texted RX8P to send me pictures of mount's assembly since there is a lot of washers and parts and maybe I messed up and assembled them in a wrong order, but it poped on perfectly and I didn't have issues installing them.
12-27-2019, 06:49 PM
#10
Registered
Yes, I can feel they are more stiff than the factory ones, but this vibration at those rpms is really bad and loud. I actually texted RX8P to send me pictures of mount's assembly since there is a lot of washers and parts and maybe I messed up and assembled them in a wrong order, but it poped on perfectly and I didn't have issues installing them.
12-27-2019, 06:51 PM
#11
Registered
Thread Starter
Join Date: Dec 2019
Posts: 15
Likes: 0
Received 0 Likes
on
0 Posts
12-27-2019, 06:57 PM
#13
So the vibration went from idle to 1000-1300 rpm when you changed the mounts.
The vibration was there before...the same? just moved to a different RPM? Or its worse after the mounts?
Kinda hard to tell whether the issue is from the mounts, got worse after the mounts? or just moved up the RPM band a bit?
The vibration was there before...the same? just moved to a different RPM? Or its worse after the mounts?
Kinda hard to tell whether the issue is from the mounts, got worse after the mounts? or just moved up the RPM band a bit?
12-27-2019, 06:59 PM
#14
Registered
Thread Starter
Join Date: Dec 2019
Posts: 15
Likes: 0
Received 0 Likes
on
0 Posts
Yeah, I already emailed him, however I'm not sure if he's going to anwer me tommorow since it is Saturday. I will try to clean MAF sensor and throttle body, and change air filter tommorow and see what happens. Thanks a lot for your all replies.
12-27-2019, 07:02 PM
#15
Registered
Thread Starter
Join Date: Dec 2019
Posts: 15
Likes: 0
Received 0 Likes
on
0 Posts
So the vibration went from idle to 1000-1300 rpm when you changed the mounts.
The vibration was there before...the same? just moved to a different RPM? Or its worse after the mounts?
Kinda hard to tell whether the issue is from the mounts, got worse after the mounts? or just moved up the RPM band a bit?
The vibration was there before...the same? just moved to a different RPM? Or its worse after the mounts?
Kinda hard to tell whether the issue is from the mounts, got worse after the mounts? or just moved up the RPM band a bit?
12-27-2019, 07:20 PM
#17
Russia, Ukraine, possibly Belarus? The reason I suggested compression because auto trans rotary engines seem to have more of this issue. If you have a rotor face or two with substantially different compression it can result in a harmonic frequency imbalance under certain conditions. But it might be a coil too. Need to spark-load test them.
12-27-2019, 07:22 PM
#18
Registered
Thread Starter
Join Date: Dec 2019
Posts: 15
Likes: 0
Received 0 Likes
on
0 Posts
So the vibration went from idle to 1000-1300 rpm when you changed the mounts.
The vibration was there before...the same? just moved to a different RPM? Or its worse after the mounts?
Kinda hard to tell whether the issue is from the mounts, got worse after the mounts? or just moved up the RPM band a bit?
The vibration was there before...the same? just moved to a different RPM? Or its worse after the mounts?
Kinda hard to tell whether the issue is from the mounts, got worse after the mounts? or just moved up the RPM band a bit?
Last edited by Oleg; 12-27-2019 at 07:33 PM.
12-27-2019, 07:25 PM
#19
Registered
Thread Starter
Join Date: Dec 2019
Posts: 15
Likes: 0
Received 0 Likes
on
0 Posts
Russia, Ukraine, possibly Belarus? The reason I suggested compression because auto trans rotary engines seem to have more of this issue. If you have a rotor face or two with substantially different compression it can result in a harmonic frequency imbalance under certain conditions. But it might be a coil too. Need to spark-load test them.
I don't know anyone in New York who is really good at rotary and could do a compression test. I only have a rotary car for a month.
Thread
Thread Starter
Forum
Replies
Last Post
Vasichko
Series I Tech Garage
14
12-17-2007 05:24 PM