Welcome to the North American Subaru Impreza Owners Club Tuesday March 19, 2024
Home Forums Images WikiNASIOC Products Store Modifications Upgrade Garage
NASIOC
Go Back   NASIOC > NASIOC General > Newbies & FAQs

Welcome to NASIOC - The world's largest online community for Subaru enthusiasts!
Welcome to the NASIOC.com Subaru forum.

You are currently viewing our forum as a guest, which gives you limited access to view most discussions and access our other features. By joining our community, free of charge, you will have access to post topics, communicate privately with other members (PM), respond to polls, upload content and access many other special features. Registration is free, fast and simple, so please join our community today!

If you have any problems with the registration process or your account login, please contact us.







* As an Amazon Associate I earn from qualifying purchases. 
* Registered users of the site do not see these ads. 
Reply
 
Thread Tools Display Modes
Old 04-24-2018, 03:21 AM   #1
masonroese
Scooby Newbie
 
Member#: 482206
Join Date: Feb 2018
Default 08 2.5L Impreza buzzing when decelerating

Hi all,

I have a question about a specific buzzing sound that occurs in my 2008 Impreza 2.5L. It only occurs between the 3.0k and 3.2k RPM, either accelerating or decelerating. The sound occurs in every gear, including neutral at a standstill. I have heard people having heat shield rattles but this sounds more high pitched than any of the heat shields I've listened to. It seems to me to have to do with the engine vibrating at a certain frequency that it causes something else to buzz loudly for a moment, but I am not sure. Any insight on the matter will be much appreciated!
* Registered users of the site do not see these ads.
masonroese is offline   Reply With Quote
Sponsored Links
* Registered users of the site do not see these ads.
Old 04-26-2018, 10:55 AM   #2
Bluefoton
Scooby Guru
 
Member#: 141373
Join Date: Feb 2007
Chapter/Region: E. Canada
Location: Quebec, QC
Vehicle:
2022 Crosstrek Sport
6MT

Default

There are a lot of things that start to rattle after 10 years. Heat shields are the main suspect, and they can make an entire symphony of noises. It's nearly impossible to pinpoint the source based on the decription alone. Check where it comes from. Underneath the engine? transmission? Near a specific belt/pulley?
Bluefoton is offline   Reply With Quote
Old 04-26-2018, 11:27 AM   #3
MNcrew952
Scooby Newbie
 
Member#: 459449
Join Date: Dec 2016
Location: Minnesnowta
Vehicle:
2017 WRX
Lapis Blue Pearl

Default

I had this happen on my 08 impreza(this was in 2012) and low and behold it was the heat shield on the exhaust. A couple metal clamps around it solved the problem, but as Bluefoton said, its an old car and there could be a number of culprits.

Best bet is to have a buddy try to pinpoint it while the car is parked and you manipulate the throttle to recreate the noise.
MNcrew952 is offline   Reply With Quote
Old 04-27-2018, 09:43 AM   #4
Charlie-III
NASIOC Supporter
 
Member#: 30669
Join Date: Dec 2002
Chapter/Region: Tri-State
Location: USA, North NJ, 07456
Vehicle:
1998 Legacy 2.5GT
Silver Sleeper BK, 5MT

Default

I usually jack the car up, get under it, and bang on things with a rubber mallet. That is a fast way to find rattles and buzzes, especially in/on the exhaust.
Start at the front, work your way back.
Charlie-III is offline   Reply With Quote
Old 06-17-2018, 02:14 AM   #5
masonroese
Scooby Newbie
 
Member#: 482206
Join Date: Feb 2018
Default

So sorry to take so long to respond! So I jacked the car up and had a helper recreate the buzzing by putting the car at around 3k RPM. I pressed on a few pieces of the exhaust, which seemed to be where the resonation was coming from, but not find the source. I put a few hose clamps around the heat shield (or what I thought was the heat shield) to no avail.

The buzz definitely goes through the exhaust, but it appears to be originating from the very front of the exhaust; maybe not even the the exhaust at all. Another thing that I noticed today is that if I am in a gear and am decelerating while pushing the shifter into gear more the vibration/buzzing is a little softer. If that didn't make sense, I mean that I am in second gear, decelerating, no clutch engagement, and am pulling back on the shifter with a little force. I will take the car to an exhaust shop on Monday to see what they think.

Final points: do you think that a bad motor mount, transmission mount, or pitch stop mount could cause weird symptoms like this? The vibration is getting worse. In fact, now if I am in the 3k-3.2k range with the AC compressor on, that makes a weird ass humming noise too. It still drives and shifts great, but I am getting very annoyed
masonroese is offline   Reply With Quote
Old 06-22-2018, 12:56 PM   #6
Impresive2009
Scooby Newbie
 
Member#: 255947
Join Date: Aug 2010
Default

you could get one of those stethoscope things the doctors use. I bought one off amazon to help me locate some noises..Not perfect but it helped.
Impresive2009 is offline   Reply With Quote
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump

All times are GMT -4. The time now is 12:54 AM.


Powered by vBulletin® Version 3.7.0
Copyright ©2000 - 2024, Jelsoft Enterprises Ltd.
Powered by Searchlight © 2024 Axivo Inc.
Copyright ©1999 - 2019, North American Subaru Impreza Owners Club, Inc.

As an Amazon Associate I earn from qualifying purchases.

When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission
Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.