General Miata Chat A place to talk about anything Miata

Loud grinding/rumbling/vibration on full boost / high rpm

Thread Tools
 
Search this Thread
 
Old 08-03-2016 | 02:12 PM
  #1  
Jack P's Avatar
Thread Starter
Newb
 
Joined: Jun 2016
Posts: 20
Total Cats: 0
From: Kent, United Kingdom
Default Loud grinding/rumbling/vibration on full boost / high rpm

Afternoon all,

Another day, another problem, recently finished my turbo conversion on my 1.8 93 enous. This problem all started after I had the car mapped.

When I put my foot down and accelerate hard, from about 5k revs onwards and at high speeds I am getting a very rough grinding/vibration but I cannot put my finger on it, the noise goes away if I put my foot on the clutch, lift up and it comes straight back.

Absolutely no noise under 70 mph or cruising a low revs.

When doing the conversion the engine was out, changed the clutch to an XTD stage 2 with a new clutch release bearing.

Ideas anyone?

Cheers
Old 08-03-2016 | 02:13 PM
  #2  
Jack P's Avatar
Thread Starter
Newb
 
Joined: Jun 2016
Posts: 20
Total Cats: 0
From: Kent, United Kingdom
Default

Forgot to add, had the car up and cannot notice anything obvious rubbing anywhere
Old 08-03-2016 | 03:12 PM
  #3  
fredb's Avatar
Junior Member
iTrader: (1)
 
Joined: Feb 2009
Posts: 274
Total Cats: 36
From: Kamloops B.C.
Default

Id start with seeing if the exhaust is contacting the chassis when the drivetrain is torqued over under load. Start with the simple stuff first.
Old 08-03-2016 | 06:04 PM
  #4  
sixshooter's Avatar
Moderator
iTrader: (12)
 
Joined: Nov 2008
Posts: 21,117
Total Cats: 3,142
From: Tampa, Florida
Default

I was going to guess motor mounts allowing something to contact.
Old 08-03-2016 | 07:27 PM
  #5  
Jack P's Avatar
Thread Starter
Newb
 
Joined: Jun 2016
Posts: 20
Total Cats: 0
From: Kent, United Kingdom
Default

Originally Posted by sixshooter
I was going to guess motor mounts allowing something to contact.
thanks guys, with motor mounts what would you check on that?

im going to have another look tomorrow however before I read this I noticed the rear baffle on the straight (before the backbox) is touching a chassis bar but I didn't see any obvious marks on the exhaust or chassis, I will try moving it or wedging some rubber in there tomorrow and see if it eliminates the problem
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
saedrin
Cars for sale/trade
6
03-10-2017 12:20 AM
Neilv
AEM
1
07-24-2016 04:23 PM
Thr33GenAccord
General Miata Chat
4
07-14-2016 07:05 PM




All times are GMT -4. The time now is 08:16 AM.