Notices
RX-8 Discussion General discussion about the RX-8 that doesn't fit in one of the specialty forums.

Buzzing noise from engine bay @ certain RPM

Thread Tools
 
Search this Thread
 
Rate Thread
 
Old 04-04-2007, 07:06 PM
  #1  
Registered
Thread Starter
 
Mobile's Avatar
 
Join Date: Mar 2007
Location: Victoria, BC
Posts: 221
Likes: 0
Received 0 Likes on 0 Posts
Buzzing noise from engine bay @ certain RPM

Not sure if this is normal or not - so I thought I would ask.

My '07 8 has about 2000 km on it. I noticed this sound right after break-in was completed and I started reving the motor, and pushing the car a bit.

I hear a light metalic buzzing noise coming from the engine bay. It sounds like there is something vibrating. One of those noises that if you put your hand on the vibrating object, it would stop.

This noise can't be reproduced by reving the engine in neutral, or slowly bringing the car up to speed - it requires load on the car for it to happen, as if it may be suspension related.

Under medium to hard acceleration, the noise starts at 6K, lasts for maybe 500rpm, then goes away. It then restarts around 7500/8K and lasts through to redline.

Sounds to me like there is just something in there that needs to be tightened up - but I thought I would see if anyone experienced a similar noise that ended up being related to the engine (which is my concern).

Last edited by Mobile; 04-04-2007 at 07:56 PM.
Old 04-04-2007, 08:27 PM
  #2  
Registered
 
Groundrush's Avatar
 
Join Date: Apr 2006
Location: Ohio
Posts: 335
Likes: 0
Received 0 Likes on 0 Posts
I have something that sounds a lot like this with mine, which is an 05 with 12k miles. Oddly, I get the same kind of rattling, during acceleration, only under load, and ONLY when the car is cold. Not reproducable with the car in neutral. Only thing is, my car does it at lower RPMs, not higher like yours. Drivin' me nuts...
Old 04-04-2007, 08:38 PM
  #3  
Registered
Thread Starter
 
Mobile's Avatar
 
Join Date: Mar 2007
Location: Victoria, BC
Posts: 221
Likes: 0
Received 0 Likes on 0 Posts
I don't rev my car when it's cold - but temp does not seem to be a factor. Does your noise seem to come from deep within the engine bay?
Old 04-04-2007, 10:35 PM
  #4  
Laid back in the pocket
 
Rhythmic's Avatar
 
Join Date: Mar 2006
Location: Blacksburg, VA
Posts: 522
Likes: 0
Received 0 Likes on 0 Posts
I've got something like this. Mine is at high rpm and usually when its cold outside. I think this could be the TSB for a rattle under the cowl. Check to see if this TSB applies to your car.
Old 04-05-2007, 08:01 AM
  #5  
DGAF
iTrader: (1)
 
Rootski's Avatar
 
Join Date: Jan 2006
Location: Austin, TX
Posts: 1,953
Likes: 0
Received 0 Likes on 0 Posts
Mine did this.. it turned out to be a loose heat shield on my aftermarket cat. If you have any aftermarket parts, check them.
Old 04-05-2007, 08:17 AM
  #6  
Banned
 
eviltwinkie's Avatar
 
Join Date: Jan 2007
Location: everywherez...
Posts: 2,756
Likes: 0
Received 1 Like on 1 Post
I started hearing a rattle after replacing the cat with a midpipe...starts at 4k...goes away...comes back at 7-8k...

Very annoying...it sounded like something metallic vibrating against something else...the only thing I am thinking is that its perhaps the factory cat-back...but since it does not really happen when in neutral its hard to pinpoint driving while the windows are down...
Old 04-05-2007, 09:35 AM
  #7  
1.21 Jiggawatts
 
Stavesacre21's Avatar
 
Join Date: May 2006
Location: Lima, OH
Posts: 1,330
Likes: 0
Received 0 Likes on 0 Posts
Originally Posted by Rootski
Mine did this.. it turned out to be a loose heat shield on my aftermarket cat. If you have any aftermarket parts, check them.
I'd say reguardles sof aftermarket or not, this is a possibility. It is likely something that wasn't quite tightened down initially. I've had problems with those heat shields over the cat in numerous cars. It can be a HUGE pita.

and it's an 07 you say? Heck...drop that sucker off at the dealer. Their problem then...not yours.
Old 04-05-2007, 11:09 PM
  #8  
Mu ha.. ha...
 
Razz1's Avatar
 
Join Date: Aug 2004
Location: Cali
Posts: 14,361
Likes: 0
Received 3 Likes on 3 Posts
Look for something loose under da hood.
Old 04-06-2007, 01:15 AM
  #9  
Club Marbles Member
 
Raptor2k's Avatar
 
Join Date: Jul 2005
Location: DFW, TX
Posts: 3,252
Likes: 0
Received 0 Likes on 0 Posts
Exactly what I've had for a couple years. Welcome to the marbles club!

It's the intake manifold's opening of fuel valves...3rd injectors come on around 7300. It ruins the sound of hitting redline a bit, but my new MS exhaust seems to have cancelled it out enough for me to stop caring.

Search, it's normal, and dealerships aren't going to fix it.

Last edited by Raptor2k; 04-06-2007 at 01:17 AM.
Old 05-12-2007, 05:37 PM
  #10  
Learning to drive
iTrader: (5)
 
PRL 84U's Avatar
 
Join Date: Oct 2006
Location: NJ
Posts: 58
Likes: 0
Received 0 Likes on 0 Posts
Reviving this thread (from a search), I've been experiencing the same problem recently, seems to be around 3000-4000 rpm, definite metal rattling, for those who have had this problem, was it the heat shield? Going to take it in soon to have it checked out. Thanks guys!
Old 05-12-2007, 06:01 PM
  #11  
Shock and Awe
 
NoTears316's Avatar
 
Join Date: Oct 2004
Location: North Carolina
Posts: 3,871
Likes: 0
Received 4 Likes on 4 Posts
Check your engine mounts. A cracked one will vibrate.
Old 05-12-2007, 08:12 PM
  #12  
Registered
Thread Starter
 
Mobile's Avatar
 
Join Date: Mar 2007
Location: Victoria, BC
Posts: 221
Likes: 0
Received 0 Likes on 0 Posts
It's going into the dealership next week to take a look. They seem to think it is the heat shield. This is not a "marble" sound.
Old 05-13-2007, 12:47 AM
  #13  
1.21 Jiggawatts
 
Stavesacre21's Avatar
 
Join Date: May 2006
Location: Lima, OH
Posts: 1,330
Likes: 0
Received 0 Likes on 0 Posts
Originally Posted by PRL 84U
Reviving this thread (from a search), I've been experiencing the same problem recently, seems to be around 3000-4000 rpm, definite metal rattling, for those who have had this problem, was it the heat shield? Going to take it in soon to have it checked out. Thanks guys!

If you're hearing the rattle with a sunroof open, be sure to confirm that it's actually the ENGINE rattling and not the sunroof. 04/05's have been synonymous with the rattling sunroof, which was even finally offered a TSB.

Just a thought.
Old 05-13-2007, 01:13 AM
  #14  
II SOCIETY
 
Phantom Menace's Avatar
 
Join Date: Nov 2006
Location: The Bay Area
Posts: 1,077
Likes: 0
Received 0 Likes on 0 Posts
You've got marbles! Search...there is a fix!
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
BigMikeATL
RX-8's For Sale/Wanted
12
05-26-2016 12:31 AM
uZu
New Member Forum
13
12-30-2015 12:35 PM
rx8inator
RX-8 Parts For Sale/Wanted
9
09-01-2015 07:18 PM
rx8inator
West For Sale/Wanted
1
08-14-2015 10:53 PM
iSki123
Series I Trouble Shooting
7
07-27-2015 12:41 PM



You have already rated this thread Rating: Thread Rating: 0 votes,  average.

Quick Reply: Buzzing noise from engine bay @ certain RPM



All times are GMT -5. The time now is 11:34 PM.