Welcome to the North American Subaru Impreza Owners Club Thursday June 30, 2022
Home Forums Images WikiNASIOC Products Store Modifications Upgrade Garage
Go Back   NASIOC > NASIOC Regional Areas > International Forum

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. 
Thread Tools Display Modes
Old 04-23-2020, 06:03 AM   #1
Scooby Newbie
Member#: 513979
Join Date: Apr 2020
Default Low speed Pinging / Pinking / Spark Knock / Detonation

Ok so I've had 2 UK N/A 160bhp Hawkeye Impreza 2.0R Sports now, EJ204 engine, one 2006 and one 2007, both with roughly same mileage when bought around 70k miles. Replicas of STi/RB320 so with aftermarket exhaust back box or CAT back systems (not sure if that's relevant or not), other than exhaust and cosmetic mods i.e spoilers etc everything else is standard.

Both had exactly the same feel and drive and both developed this issue of pinking at low speeds and possibly hesitation (sometimes) (i think) or certainly the feeling of lack of power at times anyway.

I never got to the bottom of it with my first one and got rid eventually but now its happening with my current one. I can't say when it started happening with this one but i'm sure it wasn't happening when I got it, I've had it just over 12 months now and its on 81k miles.

Now before anyone jumps in with talk about valve chatter, rod knock, piston slap, heatshields, basically anything other than pinging/detonation... it's not that! I've done extensive research into those and pinging and i'm 99.9999999999% positive that is what the noise is. It doesn't happen on idle or revving the engine stationary. It doesn't happen when the engine is cold only when its fully up to temp and while driving. It happens on acceleration under load i.e. it's more prevalent on hills but can happen on level road at low rpm's (not too low!). It happens at low speeds when going back on the throttle after a gear change or slowing up for something and only happens for a second or so. It goes away with increased rpm's or engine speed. It reminds me of a diesel engine noise. Everything I've read describing it when it happens and how its sounds fits with whats happening. It happens less with higher octane fuel but still happens. I know a heat shield noise can tend to happen in those same circumstances but on both cars? the exact same noise in the exact same circumstances?? hmmm i think not and the heatshield has had plenty of attention recently so....

On my first R Sport I tried the following (not in order):

New Plugs (NGK Iridium)
New front o2 Sensor (Denso)
New in-tank fuel filter genuine
New EGR Valve genuine
New PCV Valve genuine
Seafoam clean through throttle body
Redex in petrol (not many though)
ECU Updates from Subaru (was already up to date)
Italian Tune-ups (Many)
No ECU fault codes
Knock Sensor genuine
New air filter
Cleaned MAF (sprayed with electrical contact cleaner)
Reset ECU many times
Oil and filter change (probably aftermarket filter)
Tried higher octane fuels and different brands inc vpower
Both Subaru and a local Subaru specialist couldn't find anything wrong with the car (Probably couldn't be arsed to to look into it if there is no fault codes tbh)
My current R Sport has had:

Plugs (same as above)
Front o2 (same as above) (had gone bad anyway)
Air filter genuine
Maf cleaned (same as above)
Checked banjo bolt filters on AVCS oil solenoids (no filters present)
Oil and filter change (Millers 5w30 Synth + aftermarket filter)
No ECU fault codes
Redex fuel cleaner, Wynns CAT and o2 sensor cleaner in fuel, Millers eco max boost in fuel
Higher octane fuels different brands (Pinging less but still present)
Italian Tune-ups
Neither car had the cambelt done (while I had them) and don't know if they had ever been done (no record but book stamps), both cars should run on 95 octane and always were run on 95 Esso fuel while i had them other than when experimenting with different fuels. Never supermarket fuel (while I had them), been under the bonnet that many times can't see anything a miss no sign of anything dodgy or hoses or anything air leaks etc nothing obvious.

As you can imagine, I'm at my witts end!... Got a vag-kkl cable coming this week hopefully and I have ECU explorer on laptop so will try logging when I can and post results but in the meantime, please can anyone shed any light on this?...

* Registered users of the site do not see these ads.
4NDY1980 is offline   Reply With Quote
Sponsored Links
* Registered users of the site do not see these ads.
Old 07-17-2020, 05:45 PM   #2
Scooby Newbie
Member#: 253331
Join Date: Jul 2010

I'm working on a similar issue with my 08 Stock NA OB.

Have you tried scoping the bores to check for carbon buildup?

How about hooking the knock sensor up to a multimeter and tapping the block near it with a hammer to see if it generates voltage?

I'm thinking I might have a knock sensor issue, but one that doesn't throw a code.
vsi1600 is offline   Reply With Quote
Old 09-06-2020, 05:08 PM   #3
Scooby Newbie
Member#: 518379
Join Date: Sep 2020
Chapter/Region: International
Location: Switzerland
2005 Mercedes e220


Also working with that one, sometimes it is even hard to read guidelines from paper because all written on a foreign language (usually it is deutch or chinese) which is to hard for me to understand so I am using google before every step (youtube,articles,services, exactly like this one https://isaccurate.com/technical-translation-services) which helped me to get almost all technical terms which where written on deutsch, thats too hard for me and I am thinking about going to maintenance service but it is not too easy lol because of a lockdown all stations are closed xd

Last edited by McDaniels; 11-29-2020 at 04:02 PM.
McDaniels is offline   Reply With Quote
Old 01-22-2022, 02:31 PM   #4
Scooby Newbie
Member#: 19378
Join Date: May 2002
Location: Randers,Denmark
1997 STI Type-R 555


Its avcs that makes a knocking noise when its fully Advanced 50degress that it does around 2000-3000rpm ,
It Can be fixed by sending the ecu to russia for a remap
denmark1 is offline   Reply With Quote

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 03:24 PM.

Powered by vBulletin® Version 3.7.0
Copyright ©2000 - 2022, Jelsoft Enterprises Ltd.
Powered by Searchlight © 2022 Axivo Inc.
Copyright ©1999 - 2019, North American Subaru Impreza Owners Club, Inc.

As an Amazon Associate I earn from qualifying purchases.