Rod knock??? - Subaru Impreza GC8 & RS Forum & Community: RS25.com
 
Private Support i-Trader Ratings Become a Vendor Rules for VendorsModsUsers Contact
Subaru Impreza GC8 & RS Forum & Community: RS25.com
gc8 RSS GC8 Facebook Subaru GC8 Twitter Subaru YouTube Channel Subaru Sticker
 
Login below or Register Now
Register Mark Forums Read FAQ Advertise
Go Back   Subaru Impreza GC8 & RS Forum & Community: RS25.com > >
Rod knock???
Reply
 
Thread Tools Display Modes
Old 07-28-2019, 06:34 PM   #1
Duncan21
1.8L
 
Join Date: Jul 2019
Trader Rating: (0)
Posts: 2
Default Rod knock???

So my 2005 RS sedan has a noticeable knock from 2500-3000. It only knocks under light load, and doesn’t under heavy load or WOT. Although it has most of the symptoms of a rod bearing on its way out, I have been driving my car like this for the past 5,000 kms, and what really makes me confused is that it has not gotten any worse. So I am thinking it may be something else? I’m not sure what else it could possible be. Also note that from oil changes that the oil is relatively clean with no shavings or metal sparkles.
Duncan21 is offline   Reply With Quote
Sponsored Links
Advertisement
 
Old 07-28-2019, 08:00 PM   #2
SoCoNoHa
2.7L
 
Fav Mod: Anything custom
Join Date: Feb 2018
Location: Southern NH
Trader Rating: (1)
Posts: 439
Default

My '02 makes some suspiciously knock-y sounds right around 1500-1800, but it's not gotten any worse. I've been hoping it's piston slap.
__________________
97 LGT / 92 SVX / 95 GM∆
SoCoNoHa is offline   Reply With Quote
Old 07-29-2019, 05:46 AM   #3
silverton
2.0L Turbo
 
Fav Mod: turrrrrbbbbooooo
Join Date: Aug 2012
Location: Burien, WA
Trader Rating: (0)
Posts: 1,170
Default

Is there a possibility that it's a tap and not a knock?
__________________
2001 RS+T - 2001 LGT
silverton is offline   Reply With Quote
Old 07-29-2019, 10:20 AM   #4
Duncan21
1.8L
 
Join Date: Jul 2019
Trader Rating: (0)
Posts: 2
Default

It could definitely be a Tap and not a knock, but what could be making the tapping sound? I would think it would be something in the cylinder head.
Duncan21 is offline   Reply With Quote
Old 07-29-2019, 08:42 PM   #5
crjohnson
2.0L
 
Join Date: May 2014
Location: Melbourne
Trader Rating: (0)
Posts: 93
Default

I've had the same for a while now, I believe mine is piston slap. Sounds bloody terrible..
crjohnson is offline   Reply With Quote
Old 07-30-2019, 08:17 AM   #6
Bast
2.0L Turbo
 
Fav Mod: Prodrive all things
Join Date: Aug 2012
Location: Bay Area
Trader Rating: (4)
Posts: 1,616
Default

Mine does the same thing (MY99) and it was diagnosed with knock. Cruising around 3k rpm it sounds super sloppy. Having the AC on makes it much worse. Although mine has gotten considerable louder the last few months. It's been noticeable for over a year though.. so who knows

It's possible your sound could be the timing belt tensioner? I've heard that can make knocking sounds if it's slightly misaligned.

Take it to a shop maybe?
__________________
Wolves don't lose sleep over the opinions of sheep.
Bast is offline   Reply With Quote
Old 07-31-2019, 03:57 AM   #7
Samurai Jack
1.8L
 
Car: 2002 WRX
Fav Mod: Enemy of Aku
Join Date: Apr 2011
Location: Not In My Own Tme
Trader Rating: (0)
Posts: 35
Default

Quote:
Originally Posted by Bast View Post
It's possible your sound could be the timing belt tensioner? I've heard that can make knocking sounds if it's slightly misaligned.
There have been a number of threads over on NASIOC concerning what was believed to be rod knock but turned out to be the timing belt tensioner.


Several included videos of the sound and it sounded very similar to rod knock, but wasn't.
You might want to peruse NASIOC for rod knock and see if any of what they were experiencing sounds like what you have going on.


YouTube most likely has the same videos.
Samurai Jack is offline   Reply With Quote
Old 08-06-2019, 04:39 PM   #8
rskm1
2.2L
 
Car: 2000 coupe, electron blue pear
Join Date: Apr 2005
Location: MN
Trader Rating: (0)
Posts: 164
Default

A small exhaust leak that's close to the manifold can sound very "knock"-like and metallic. It doesn't sound the same as an exhaust leak near the muffler, because the explosion is *right there* and only audible for 1 of the 4 firing order.

So that might be worth looking into. Watch under the hood and under the car while givin'er a good rev when it's pitch black out. Also poke around with a stethoscope to see if you can isolate the location.
rskm1 is offline   Reply With Quote
Reply


Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
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 -7. The time now is 01:51 PM.


Powered by vBulletin® Version 3.8.9
Copyright ©2000 - 2019, vBulletin Solutions, Inc.
vBulletin Security provided by vBSecurity v2.2.2 (Pro) - vBulletin Mods & Addons Copyright © 2019 DragonByte Technologies Ltd.
Copyright © 2019 VerticalScope Inc.
Designed & Powered by Domain Architect